Caffeine (capsules, gum and anhydrous powder) trials recruiting now
40 registrations that name caffeine as a study arm and are recruiting or about to, as ClinicalTrials.gov listed them on Oct 20, 2026. Read each listing for its full criteria and current status.
Kymata never assesses eligibility. Each listing names its own criteria; only its study team can say whether someone can join. Trial doses are given under the trial's monitoring and are not a schedule for anyone outside it.
Filter 40 registrations
Status
Phase
13US sites across 10 states
1
2 to 4
5 to 19
20 or more
All 40 registrations
RecruitingNCT07665723
An Early-Stage Study in Multiple Clinics of How Afimkibart May Affect the Body's Processing of Medicines That Rely on Cytochrome P450 Enzymes in Participants With Ulcerative Colitis
Phase 1
Hoffmann-La Roche
About 25 people
Started Jun 29, 2026
In plain words A Phase 1 study of caffeine in people 18 to 60, run by Hoffmann-La Roche. It plans to enroll about 25 people at 18 sites, 3 of them in the US.
Who it lists and where
Who the trial lists, as registered
Lists people 18 to 60. Conditions: Active Ulcerative Colitis.
Body weight >= 40kg
Agreement to adhere to the contraceptive requirements
Confirmed diagnosis of UC with supportive clinical, endoscopic, and histopathological evidence
Active UC confirmed by endoscopy (flexible sigmoidoscopy or colonoscopy) extending >=15 cm from the anal verge
1 more inclusion criterion and the exclusion criteria are on the listing.
What it tests, as registered
Afimkibart; Caffeine; Warfarin; Omeprazole; Dextromethorphan; Midazolam; Vitamin K
Registered summary
The purpose of this study is to evaluate the disease-drug-drug interaction (DDDI) potential of afimkibart (also known as RO7790121). This will be assessed by the characterization of the pharmacokinetics (PK) of cytochrome P450 (CYP) enzyme substrates alone and after administration of afimkibart in participants with moderately to severely active ulcerative colitis (UC).
Where, as registered
3 US sites in 2 states; also Poland (9), United Kingdom (3), Belgium (2), Germany (1).
RecruitingNCT05588934
Caffeine Optimization Versus Standard Caffeine Dosage (2B-2)
No phase
University of Arizona
About 180 people
Started Jun 9, 2023
In plain words A study of caffeine in people 18 to 39, run by University of Arizona. It plans to enroll about 180 people at 2 US sites.
Who it lists and where
Who the trial lists, as registered
Lists people 18 to 39; healthy volunteers accepted. Conditions: Sleep Deprivation; Caffeine.
Age 18-39 years of age
Must demonstrate adequate comprehension of the protocol by achieving a score of at least 80% correct on a short multiple-choice quiz
The exclusion criteria are on the listing.
What it tests, as registered
Caffeine Gum; Placebo Gum
Registered summary
This clinical trial will be a comparison between personalized recommended caffeine dosing regimen versus the standard recommended caffeine dosing regimen for sustaining performance during sleep deprivation and minimizing side effects and subsequent sleep disruption. The full summary is on the listing.
Where, as registered
2 US sites in 1 state.
RecruitingNCT07339722
A Study of LY4515100 in Healthy Participants
Phase 1
Eli Lilly and Company
About 123 people
Started Jan 15, 2026
In plain words A Phase 1 study of caffeine in people 18 to 65, run by Eli Lilly and Company. It plans to enroll about 123 people at 1 US site.
Who it lists and where
Who the trial lists, as registered
Lists people 18 to 65; healthy volunteers accepted. Conditions: Healthy.
Are overtly healthy as determined by medical evaluation including medical history, physical examination, laboratory tests, vital signs, and cardiac monitoring.
Have a body mass index within the range of 18.5 to 32.0 kilograms per square meter (kg/m²) (inclusive).
Individuals not of childbearing potential (INOCBP) may participate in this trial.
The exclusion criteria are on the listing.
What it tests, as registered
LY4515100 via SAD; LY4515100 via MAD; LY4515100; Itraconazole; Caffeine; Digoxin; Iohexol; Metformin; Rosuvastatin; Placebo
Registered summary
The main purpose of this study is to assess the safety and tolerability of LY4515100 when given orally to healthy participants. LY4515100 will be given by itself or with other medicines. Blood tests will be performed to investigate how the body processes the study drug and how the study drug affects the body. The study will have 3 parts and will last about 50 days. For each participant in Part A, the study will include a stay in the Clinical Research Unit (CRU) lasting about 6 days. For each participant in Part B, the study will include a stay in the CRU lasting about 15 days. The full summary is on the listing.
Where, as registered
1 US site in 1 state.
RecruitingNCT07262060
Improving Preterm Kidney Outcomes With Caffeine
Phase 2
University of Wisconsin, Madison
About 114 people
Started May 28, 2026
In plain words A Phase 2 study of caffeine in people 12 hours to 96 hours, run by University of Wisconsin, Madison. It plans to enroll about 114 people at 1 US site.
Who it lists and where
Who the trial lists, as registered
Lists people 12 hours to 96 hours. Conditions: Kidney Injury; Pre-Term.
Gestational age at birth between 23 0/7 and 29 6/7 weeks.
Able to have near-infrared spectroscopy (NIRS) monitoring of cerebral and kidney oxygenation.
Able to receive IV medications.
Indwelling umbilical arterial catheter (UAC), umbilical venous catheter (UVC), peripheral arterial line (PAL), or peripherally inserted central catheter (PICC) already in place that can draw blood.
2 more inclusion criteria and the exclusion criteria are on the listing.
What it tests, as registered
Caffeine citrate; Placebo
Registered summary
This study is being done to see if additional caffeine citrate (20 milligrams per kilogram IV bolus) helps babies with low kidney oxygenation already being treated with caffeine citrate (20 milligrams per kilogram IV bolus on day of life (DOL) 1 followed by 8 milligrams per kilogram daily maintenance). The investigators hypothesize that additional caffeine will improve kidney oxygen levels, while not causing any brain injury, and may reduce rates of acute kidney injury compared to placebo. The full summary is on the listing.
Where, as registered
1 US site in 1 state.
RecruitingNCT06538584
Dex +/- Caffeine Sedation in a Post-MRI Recovery in a Pediatric Population
Phase 1 and 2
University of Chicago
About 100 people
Started Sep 9, 2024
In plain words A Phase 1 and 2 study of caffeine in people 3 to 12, run by University of Chicago. It plans to enroll about 100 people at 1 US site.
Who it lists and where
Who the trial lists, as registered
Lists people 3 to 12; healthy volunteers accepted. Conditions: Enhanced Recovery After Surgery in a Pediatric Population.
Undergo Magnetic Resonance Imaging (MRI) scan
Age ≥3 and ≤ 12 yr old
Both Male and Female
Weight ≤33.3 kg
7 more inclusion criteria and the exclusion criteria are on the listing.
What it tests, as registered
Caffeine citrate 15mg/kg; 0.9% Sodium Citrate
Registered summary
Dexmedetomidine (Dex), a selective α2-adrenergic receptor agonist, is the most used sedative for procedural sedation in children and in pediatric Intensive Care Unit (PICU) because it is associated with less respiratory depression and also less neurotoxicity; rather Dex appears neuroprotective. Unfortunately, Dex is associated with very long emergence times and may cause bradycardia and hypotension. The full summary is on the listing.
Where, as registered
1 US site in 1 state.
RecruitingNCT07216365
Caffeine Optimization for Oxygen Saturation Index in ELBW Infants
Phase 2
University of Rochester
About 40 people
Started Jul 15, 2026
In plain words A Phase 2 study of caffeine in people 0 days to 27 weeks, run by University of Rochester. It plans to enroll about 40 people at 1 US site.
Who it lists and where
Who the trial lists, as registered
Lists people 0 days to 27 weeks. Conditions: Neonatal Apnea; Infants.
URMC Inborn Newborn infants born with gestational age of 22 weeks 0 days - 27 weeks 6 days or infants OR ≥ 28 weeks with a birthweight < 1000 grams
The exclusion criteria are on the listing.
What it tests, as registered
Caffeine Citrate
Registered summary
The goal of this clinical trial is to determine whether a higher dose of caffeine citrate can improve breathing and reduce health complications in extremely premature infants, specifically those born before 28 weeks of pregnancy, known as ELGAN infants. These babies often struggle with breathing due to underdeveloped lungs, and caffeine is commonly used to help support their respiratory function. However, the most effective and safest dose has not yet been clearly established. The full summary is on the listing.
Where, as registered
1 US site in 1 state.
RecruitingNCT07570121
Pharmacokinetics and Placental Transfer of Caffeine
Phase 1
Indiana University
About 30 people
Started Jun 1, 2026
In plain words A Phase 1 study of caffeine in female participants 18 and older, run by Indiana University. It plans to enroll about 30 people at 1 US site.
Who it lists and where
Who the trial lists, as registered
Lists female participants 18 and older. Conditions: Preterm Labor With Preterm Delivery; Premature Birth; Apnea of Prematurity; Respiratory Distress Syndrome; Bronchopulmonary Dysplasia.
Pregnant women with risk of preterm delivery at 23 - 31+6 weeks with singleton gestation who are inpatient without a plan for discharge before delivery.
Informed consent provided for participation.
Cesarean delivery.
The exclusion criteria are on the listing.
What it tests, as registered
Caffeine citrate
Registered summary
The goal of this study is to learn how a pregnant person's body processes caffeine and how much caffeine crosses the placenta to the baby. A small dose of caffeine will be given to each pregnant participant before delivery. Blood will be drawn to measure caffeine levels in the pregnant mother. Blood will also be taken from the placenta and from the newborn to measure caffeine levels. This data will be used to form a computer model of the metabolism of caffeine during pregnancy.
Where, as registered
1 US site in 1 state.
RecruitingNCT07854223
Effects of Pre-Run Nutritional Supplements During a Fixed-Pace 5 km Treadmill Run
No phase
St. Louis University
About 20 people
Starts Oct 2026 (estimated)
In plain words A study of caffeine in people 18 to 35, run by St. Louis University. It plans to enroll about 20 people at 1 US site.
Who it lists and where
Who the trial lists, as registered
Lists people 18 to 35; healthy volunteers accepted. Conditions: Exercise Physiology; Nutritional Supplementation.
Age 18-35 years
Healthy adult
Able to provide written informed consent
Regularly engaged in running-based aerobic training at least 3 times per week for at least 30 minutes per session during the past 3 months
3 more inclusion criteria and the exclusion criteria are on the listing.
This study will examine how three commonly used pre-run nutritional supplements-caffeine, L-citrulline, and an exogenous ketone supplement-affect physiological and perceptual responses during a fixed-pace 5 km treadmill run in healthy, physically active runners. Participants will complete one screening and baseline visit followed by four experimental visits in a randomized order. At each experimental visit, participants will receive caffeine, L-citrulline, an exogenous ketone supplement, or placebo before completing a fixed-pace 5 km treadmill run. The full summary is on the listing.
Where, as registered
1 US site in 1 state.
RecruitingNCT06763172
Effects of Caffeine on Reinforcement Learning in Healthy Adults Using PET/MRI
Phase 4
Hsiao-Ying Wey
About 12 people
Started May 17, 2023
In plain words A Phase 4 study of caffeine in people 18 to 45, run by Hsiao-Ying Wey. It plans to enroll about 12 people at 1 US site.
Who it lists and where
Who the trial lists, as registered
Lists people 18 to 45; healthy volunteers accepted. Conditions: Healthy; Caffeine; Adenosine; Dopamine D2/3 Receptor Availability.
1 more inclusion criterion and the exclusion criteria are on the listing.
What it tests, as registered
Caffeine (200 mg); Placebo
Registered summary
This research study aims to determine whether and how caffeine intake affects learning process through reward feedback compared to placebo. The data acquired from this study would improve our understanding on the consequence and mechanism of caffeine intake in the aspect of learning process. Participants will perform a reinforcement learning task (i.e. Probabilistic Selection Task) and a motor inhibition task (i.e. Go/NoGo task) in a brain scan. The scan will be done with the Siemens Biograph mMR positron emission tomography (PET)/ magnetic resonance imaging (MRI) 3 Tesla scanner. The full summary is on the listing.
Where, as registered
1 US site in 1 state.
RecruitingNCT07212803
Effects of Energy Drinks on Cardiovascular Endpoints
Phase 4
University of the Pacific
About 3 people
Started Nov 1, 2025
In plain words A Phase 4 study of caffeine in people 18 to 40, run by University of the Pacific. It plans to enroll about 3 people at 1 US site.
Who it lists and where
Who the trial lists, as registered
Lists people 18 to 40; healthy volunteers accepted. Conditions: Healthy Volunteers; Safety After Oral Intake.
Healthy male or female adults 18-40 years of age
Female participants of child-bearing potential must have a negative pregnancy test at the baseline visit
Participants must be willing to refrain from caffeine and alcohol use 72 hours prior to sessions on study days
Participants must be willing and able to: (1.) Consume up to 1 liter of fluid within a 30-minute period per visit (2.) Swallow a single large capsule per visit
2 more inclusion criteria and the exclusion criteria are on the listing.
What it tests, as registered
Energy Drink A + Placebo Capsule; Placebo Drink + Moxifloxacin Capsule; Placebo Drink + Caffeine Capsule; Placebo Drink + Placebo Capsule; Energy Drink B; Control Product + Taurine; Control Product + Caffeine + Taurine; Lower Dose Energy Drink A
Registered summary
This is a clinical trial looking at the impact of energy drinks on heart related parameters. The study will enroll 3 participants who will be exposed to 8 different interventions.
Where, as registered
1 US site in 1 state.
RecruitingNCT06855108
Caffeine for Hypoxic Ischemic Encephalopathy
Phase 3
NICHD Global Network for Women's and Children's Health
About 830 people
Started Apr 8, 2026
In plain words A Phase 3 study of caffeine in people up to 6 hours, run by NICHD Global Network for Women's and Children's Health. It plans to enroll about 830 people at 7 sites, none in the US.
Who it lists and where
Who the trial lists, as registered
Lists people up to 6 hours. Conditions: Hypoxic Ischemic Encephalopathy (HIE).
Liveborn infants ≥36 weeks
Birth weight ≥1800 grams
Meets physiologic criteria for moderate to severe HIE, defined as meeting either of the following two criteria:
Criterion #1: Severe acidosis, defined as an umbilical cord sample or neonatal serum sample within one hour after birth demonstrating any of following criteria:
21 more inclusion criteria and the exclusion criteria are on the listing.
CHIME is a randomized, parallel-arm, double-blind, placebo-controlled trial focused on infants with hypoxic ischemic encephalopathy (HIE). The trial will recruit neonates who are diagnosed with HIE within six hours after birth based on physiologic criteria (acidosis noted on an umbilical cord or early \[\<1 hour\] postnatal blood sample) and neurologic criteria (modified Sarnat exam consistent with encephalopathy). The full summary is on the listing.
Where, as registered
No US site; India (2), Bangladesh (1), Democratic Republic of the Congo (1), Guatemala (1), Pakistan (1), Zambia (1).
RecruitingNCT06518603
Caffeine Citrate in Preterm Infants at Risk of Apnea in Zambia
Phase 4
University of Alabama at Birmingham
About 340 people
Started Jun 17, 2026
In plain words A Phase 4 study of caffeine in people 0 days to 12 months, run by University of Alabama at Birmingham. It plans to enroll about 340 people at 1 site, none in the US.
Who it lists and where
Who the trial lists, as registered
Lists people 0 days to 12 months. Conditions: Premature Infant Disease; Apnea of Prematurity; Development, Infant.
29 0/7 to 33 6/7 weeks GA (or with a birth weight 1.0 to 2.0 kg if pregnancy dating is unreliable) admitted to the UTH NICU,
On methylxanthines with plans to discontinue on methylxanthine,
Off oxygen therapy for >48 hours at the time of evaluation for eligibility,
Receiving full daily feeds,
2 more inclusion criteria and the exclusion criteria are on the listing.
What it tests, as registered
Caffeine citrate 20mg/kg/day; Placebo-Sterile water 1ml/kg/day
Registered summary
The goal of this clinical trial is to learn if caffeine citrate prevents apneic events that result in sick visits in moderately preterm infants after discharge from the hospital. It will also learn if the use of caffeine leads to better developmental outcomes at 12 months of age. Our research questions are: 1. Does continued treatment of moderately preterm newborns with caffeine citrate after hospital discharge prevent or decrease apneic events that result in sick visits? 2. The full summary is on the listing.
Where, as registered
No US site; Zambia (1).
RecruitingNCT04570085
Effect of CAFfeine on Cognition in Alzheimer's Disease
Phase 3
University Hospital, Lille
About 248 people
Started Mar 1, 2021
In plain words A Phase 3 study of caffeine in people 50 and older, run by University Hospital, Lille. It plans to enroll about 248 people at 17 sites, none in the US.
Who it lists and where
Who the trial lists, as registered
Lists people 50 and older. Conditions: Alzheimer Disease.
Age ≥ 50 at screening
Probable Alzheimer dementia according to the criteria of the National Institute on Aging-Alzheimer's Association; diagnosis must be supported by brain imaging (CT or MRI) and blood test (including ionogram, kidney and liver function,…
MMSE score ≥16
Presence of an informant and caregiver, living with the patient
1 more inclusion criterion and the exclusion criteria are on the listing.
What it tests, as registered
Caffeine; Placebo
Registered summary
Sporadic Alzheimer's disease is a multifactorial illness arising a major medico-economic stakes for our aging societies. There is currently no curative treatment available. Coffee is a complex beverage with psychostimulant properties whose main effective element, caffeine, has a pleiotropic effect on the central nervous system. Caffeine pharmacological properties enable its use like an Alzheimer's disease symptomatic treatment. Its supposed benefits mustn't obscure anxiety and insomnia caffeine effect at large dose, which Alzheimer's patients might be more vulnerable. The full summary is on the listing.
Where, as registered
No US site; France (17).
RecruitingNCT06401083
The Effect of an Additional Pre-extubational Loading Dose of Caffeine-citrate
Phase 4
Semmelweis University
About 226 people
Started Dec 21, 2023
In plain words A Phase 4 study of caffeine in people of any age, run by Semmelweis University. It plans to enroll about 226 people at 2 sites, none in the US.
Who it lists and where
Who the trial lists, as registered
Lists people of any age. Conditions: Apnea of Prematurity; Premature Birth; Respiratory Failure.
Premature infant born before 32nd week of gestation is completed;
Had been mechanically ventilated for at least 48 hours;
Before the first planned extubation.
The exclusion criteria are on the listing.
What it tests, as registered
Caffeine citrate
Registered summary
The goal of this clinical trial is to answer whether the use of a single loading dose (20 mg/kg) of caffeine citrate one hour before extubation has an impact on the success rate of extubation among preterm neonates. In addition, the investigators would like to assess the frequency of apneas and side effects of the intervention, as well as the development of NEC, BPD, IVH, PVL, and long-term neurodevelopmental outcomes in the investigated populations. According to institutional protocol, preterm infants born before the 32nd week of gestation receive a standard dose of caffeine citrate therapy. The full summary is on the listing.
Where, as registered
No US site; Hungary (2).
RecruitingNCT06026163
Caffeine as an Adjuvant Therapy for Late Preterm Infants With Respiratory Distress
Phase 2 and 3
Ministry of Health, Saudi Arabia
About 134 people
Started Oct 12, 2023
In plain words A Phase 2 and 3 study of caffeine in people 1 day to 3 days, run by Ministry of Health, Saudi Arabia. It plans to enroll about 134 people at 2 sites, none in the US.
Who it lists and where
Who the trial lists, as registered
Lists people 1 day to 3 days. Conditions: Prematurity; Respiratory Disease; Ventilator Lung; Newborn.
Newborn infants at gestational age 34 0/7 through 36 6/7
Presented with respiratory distress
Require respiratory support in the form of any of the following :
The exclusion criteria are on the listing.
What it tests, as registered
Caffeine citrate; Placebo
Registered summary
Use of caffeine citrate in late-preterm infants with respiratory distress is questionable. Oliphant and colleagues found in a recently published study that caffeine therapy use in late-preterm infants at a loading dose of 20 and 40 mg/kg and maintenance dose of 10 and 20 mg/kg/day reduces the incidence of intermittent hypoxia events by 61 and 67% respectively. The investigators hypothesized that caffeine will improve respiratory drive, prevent apnea, shorten the hospital stay and improve arousal state in late preterm infants. The full summary is on the listing.
Where, as registered
No US site; Saudi Arabia (2).
RecruitingNCT07022496
Assessment of Oral Caffeine Intake in Changing the Severity of Acute Migraine Attack Using VAS Score Among Patients Attending Headache and Neurology Outpatients Clinic of Ainshams University Hospitals
Phase 4
Ain Shams University
About 120 people
Started Apr 26, 2023
In plain words A Phase 4 study of caffeine in people 18 to 60, run by Ain Shams University. It plans to enroll about 120 people at 1 site, none in the US.
Who it lists and where
Who the trial lists, as registered
Lists people 18 to 60. Conditions: Migraine; Migraine Disease; Migraine Headache; Migraine Headache, With or Without Aura; Migraine, Acute.
Caffeine extracted from green tea to abort acute attack of Migraine
Where, as registered
No US site; Egypt (1).
RecruitingNCT06432504
Variation in the Impact of Coffee on the Metabolic Rate
No phase
Shenzhen Institutes of Advanced Technology ,Chinese Academy of Sciences
About 100 people
Started Mar 6, 2024
In plain words A study of caffeine in people 18 to 40, run by Shenzhen Institutes of Advanced Technology ,Chinese Academy of Sciences. It plans to enroll about 100 people at 1 site, none in the US.
Who it lists and where
Who the trial lists, as registered
Lists people 18 to 40; healthy volunteers accepted. Conditions: Healthy.
What it tests, as registered
Caffeine content
Registered summary
The purpose of this study is to explore variation in the impact of coffee on metabolic rate. The investigators plan to recruit healthy participants, half male and half female.
Where, as registered
No US site; China (1).
RecruitingNCT07193264
Impact of Chronic and Acute Caffeine Intake on the Hematopoietic System
No phase
Jasmin Rettkowski
About 100 people
Started Nov 5, 2025
In plain words A study of caffeine in people 18 and older, run by Jasmin Rettkowski. It plans to enroll about 100 people at 2 sites, none in the US.
Who it lists and where
Who the trial lists, as registered
Lists people 18 and older; healthy volunteers accepted. Conditions: Healthy Adults; Hematopoietic System; Caffeine.
Able to give consent.
Healthy adults aged ≥ 18 years.
Regular caffeine consumers (≥1 coffee cup/day or ≥1 energy drink/day) or non-consumers (≤1 cup/month and ≤1 energy drink/month) for at least 6 months.
Willingness to comply with fasting requirements and study procedures.
The exclusion criteria are on the listing.
What it tests, as registered
Caffeine (200 mg)
Registered summary
This study investigates how caffeine intake affects blood stem and progenitor cells in healthy adults. The trial will compare people who regularly consume caffeine with those who consume very little or none. All participants will receive a single 200 mg caffeine tablet (similar to one cup of coffee) under fasting conditions. Blood samples will be collected before and three hours after caffeine intake. The study will assess whether caffeine influences the mobilization of blood stem and progenitor cells from the bone marrow into the bloodstream. The full summary is on the listing.
Where, as registered
No US site; Switzerland (2).
RecruitingNCT07625358
Investigating the Effect of Caffeine and Alcohol on Pupil Dynamics
No phase
National University of Singapore
About 100 people
Starts Jun 1, 2026 (estimated)
In plain words A study of caffeine in people 30 to 50, run by National University of Singapore. It plans to enroll about 100 people at 1 site, none in the US.
The goal of this study is to understand how caffeine and alcohol affect the ocular and physiological systems, especially how the pupil (the aperture in the colored part of the eye) responds to light. It will also test whether these changes can be used to detect recent caffeine or alcohol intake using a portable eye device. The main questions it aims to answer are: 1. How does caffeine change pupil responses, eye movements, and other ocular and physiological measurements? 2. How does alcohol change these same ocular and physiological responses? 3. The full summary is on the listing.
Where, as registered
No US site; Singapore (1).
RecruitingNCT07710547
TCP-600 Supplementation and Performance Response in Professional Football Players
No phase
Vizja University in Warsaw
About 65 people
Starts Sep 2026 (estimated)
In plain words A study of caffeine in male participants 18 to 37, run by Vizja University in Warsaw. It plans to enroll about 65 people at 3 sites, none in the US.
Who it lists and where
Who the trial lists, as registered
Lists male participants 18 to 37; healthy volunteers accepted. Conditions: Athletic Performance; Cognitive Fatigue; Exercise Recovery; Football-Specific Performance; Perceptual-cognitive Performance.
Male professional or highly trained football players aged 18-37 years.
Regular participation in structured football training and team activities.
Minimum of 5 years of structured football training experience.
Regular involvement in club training during the study period.
6 more inclusion criteria and the exclusion criteria are on the listing.
What it tests, as registered
Placebo; Taurine; Caffeine; Phosphatidylserine
Registered summary
This study will examine whether a 28-day supplementation protocol containing taurine, caffeine, and phosphatidylserine can help professional male football players maintain physical performance, cognitive function, recovery-related readiness, and selected football-specific perceptual-cognitive performance. Participants will be randomly assigned to receive either placebo or a phosphatidylserine-containing multi-ingredient supplement. The full summary is on the listing.
Where, as registered
No US site; Poland (3).
RecruitingNCT06712511
The Effect of Coffee on Energy Expenditure and Caffeine Metabolism
No phase
Shenzhen Institutes of Advanced Technology ,Chinese Academy of Sciences
About 60 people
Started Oct 23, 2024
In plain words A study of caffeine in people 18 to 40, run by Shenzhen Institutes of Advanced Technology ,Chinese Academy of Sciences. It plans to enroll about 60 people at 1 site, none in the US.
Who it lists and where
Who the trial lists, as registered
Lists people 18 to 40; healthy volunteers accepted. Conditions: Healthy.
Healthy adults.
Must be able to drink coffee.
The exclusion criteria are on the listing.
What it tests, as registered
Caffeine content
Registered summary
Obesity is a risk factor for chronic diseases, and improving energy expenditure is a way to prevent and treat obesity. The purpose of this project is to explore the relationship between the effect of coffee on energy expenditure and caffeine metabolism, which has important significance in the rational application of caffeine.
Where, as registered
No US site; China (1).
RecruitingNCT07369726
Effects of Mobilization and Caffeine After Cesarean
No phase
KTO Karatay University
About 60 people
Started Nov 25, 2025
In plain words A study of caffeine in female participants 18 to 35, run by KTO Karatay University. It plans to enroll about 60 people at 1 site, none in the US.
Women who underwent cesarean delivery under spinal anesthesia,
Having a post-cesarean pain level of 4 or higher,
Being able to understand and write Turkish and communicate effectively with researchers.
The exclusion criteria are on the listing.
What it tests, as registered
caffeine consumption; Decaffeinated coffee
Registered summary
This study Maims to assess bowel motility, pain and psychological well-being in women in the post-cesarean period by mobilizing them early and encouraging them to consume coffee.
Where, as registered
No US site; Turkey (Türkiye) (1).
RecruitingNCT07738523
Caffeine Consumption and Rate Control in Permanent Atrial FIBrillation: The CAFIB Trial
Phase 2 and 3
Hospital Universitario Getafe
About 50 people
Starts Jul 27, 2026 (estimated)
In plain words A Phase 2 and 3 study of caffeine in people 18 to 80, run by Hospital Universitario Getafe. It plans to enroll about 50 people at 1 site, none in the US.
Who it lists and where
Who the trial lists, as registered
Lists people 18 to 80. Conditions: Atrial Fibrillation (AF); Permanent Atrial Fibrillation; Coffee Consumption; Caffeine Abuse.
Age ≥18 years.
Permanent atrial fibrillation diagnosed for more than 3 months.
Stable rate-control status, defined as a resting heart rate <110 bpm without changes in rate-control medication during the previous 2 months.
Habitual caffeine consumption (≥1 cup/day of caffeinated coffee).
1 more inclusion criterion and the exclusion criteria are on the listing.
What it tests, as registered
Dietary Caffeine Intake
Registered summary
The CAFIB trial is a multicenter, randomized, open-label, crossover clinical trial designed to determine whether habitual caffeine consumption in coffe adversely affects rate control in patients with permanent atrial fibrillation (AF). The rationale stems from the discrepancy between traditional clinical recommendations, which often advise patients with arrhythmias to avoid caffeine, and the growing body of evidence suggesting that moderate coffee consumption is not associated with an increased risk of AF and may even confer cardiovascular benefits. The full summary is on the listing.
Where, as registered
No US site; Spain (1).
RecruitingNCT07210099
The Effect of Short-term Supplementation of OliPhenolia® on Fat Oxidation
No phase
Anglia Ruskin University
About 40 people
Started May 30, 2025
In plain words A study of caffeine in people 21 and older, run by Anglia Ruskin University. It plans to enroll about 40 people at 1 site, none in the US.
Who it lists and where
Who the trial lists, as registered
Lists people 21 and older; healthy volunteers accepted. Conditions: Healthy.
Men and women, UK based, above 21 years of age with a body mass index (BMI) >18 and <30 kg·m2 determined during baseline testing
Considered to be recreationally active i.e. approximately 150mins of general physical activity/ exercise per week (meeting the WHO physical activity guidelines); and a VO2peak (fitness) score >20 and <50 mL·kg-1·min-1 determined during…
No known history (including family history) of heart abnormalities, hypertension, coronary heart disease or diabetes (determined from pre-study health screen questionnaire).
Not currently suffering from any musculoskeletal injury, or any other reason that may prevent participation in cardiovascular exercise.
4 more inclusion criteria and the exclusion criteria are on the listing.
What it tests, as registered
Concentrated olive fruit water; Placebo; Anhydrous caffeine; Placebo beverage
Registered summary
There is current research interest in the use of fruit and plant-based food products containing high levels of natural antioxidants and their impact on exercise, which may be particularly beneficial for recreationally or low-active populations. One such product is an olive extract drink (called OliPhenolia®) produced by Fattoria La Vialla (an organic farm based in Northern Italy) and commercially available for the general public. The full summary is on the listing.
Where, as registered
No US site; United Kingdom (1).
RecruitingNCT06712667
The Effect of Coffee on People with High Intensity Exercise and the Characteristics of Caffeine Metabolism
No phase
Shenzhen Institutes of Advanced Technology ,Chinese Academy of Sciences
About 24 people
Started Oct 23, 2024
In plain words A study of caffeine in people 18 to 40, run by Shenzhen Institutes of Advanced Technology ,Chinese Academy of Sciences. It plans to enroll about 24 people at 1 site, none in the US.
Who it lists and where
Who the trial lists, as registered
Lists people 18 to 40; healthy volunteers accepted. Conditions: Healthy.
What it tests, as registered
Caffeine content
Registered summary
The purpose of this project is to explore the relationship between the effect of coffee on exercise performance and caffeine metabolism.
Where, as registered
No US site; China (1).
Not yet recruitingNCT06461429
PLatform for Adaptive Trials In Perinatal UnitS - [Core Protocol]
No phase
University of Melbourne
About 100,000 people
Starts Nov 1, 2025 (estimated)
In plain words A study of caffeine in people of any age, run by University of Melbourne. It plans to enroll about 100,000 people and lists no sites yet.
Who it lists and where
Who the trial lists, as registered
Lists people of any age. Conditions: Preterm Birth.
Pregnant and at risk of preterm birth
Receiving care at a participating site at the time of eligibility assessment.
Meets the eligibility criteria for at least one domain.
The exclusion criteria are on the listing.
What it tests, as registered
Erythromycin; Amoxicillin and Erythromycin; Azithromycin; Caffeine citrate 20 mg/kg load and 10 mg/kg daily maintenance.; Caffeine citrate 30 mg/kg load and 15 mg/kg daily maintenance.; Caffeine citrate 40 mg/kg load and 20 mg/kg daily maintenance
Registered summary
PLATIPUS is an adaptive platform trial aimed at improving the health of infants born preterm (before 37 weeks' gestation). PLATIPUS will compare how different treatments and care provided to pregnant women and people at risk of preterm birth and infants born preterm affect infant health. The main questions PLATIPUS aims to answer are: 1. What effect/s do different treatments/care provided to pregnant women and people at risk of preterm birth have on the health of their infants? (Pregnancy domains) 2. The full summary is on the listing.
Where, as registered
No sites listed yet.
Not yet recruitingNCT06972849
Caffeine Citrate to Improve Neonatal Outcomes.
No phase
University of Melbourne
About 3,900 people
Starts Oct 2025 (estimated)
In plain words A study of caffeine in people up to 32 weeks, run by University of Melbourne. It plans to enroll about 3,900 people and lists no sites yet.
Who it lists and where
Who the trial lists, as registered
Lists people up to 32 weeks. Conditions: Apnea of Prematurity.
Born before 37 weeks gestation
Receiving pregnancy care at a participating site (hospital) at the time of eligibility assessment and
Meet eligibility criteria for one or more platform domains.
(Parent) Inability to consent for their infant, unless a domain-level waiver of consent is deemed appropriate.
14 more inclusion criteria and the exclusion criteria are on the listing.
What it tests, as registered
Caffeine citrate
Registered summary
The goal of this clinical trial to learn what dose/s of caffeine citrate works to treat preterm born babies who have episodes where they stop breathing. It will also learn about the safety of different doses of caffeine citrate for the variety of preterm-born babies that are prescribed this. The full summary is on the listing.
Where, as registered
No sites listed yet.
Not yet recruitingNCT07742150
Placebo Effect in Field-Based Physical Performance
No phase
Poznan University of Physical Education
About 120 people
Starts Sep 1, 2026 (estimated)
In plain words A study of caffeine in people 20 to 35, run by Poznan University of Physical Education. It plans to enroll about 120 people at 1 site, none in the US.
Who it lists and where
Who the trial lists, as registered
Lists people 20 to 35; healthy volunteers accepted. Conditions: Physical Performance; Placebo Effect; Cognitive Performance.
Age between 20 and 35 years,
Healthy adults,
Regular physical activity,
Normal or corrected-to-normal vision,
1 more inclusion criterion and the exclusion criteria are on the listing.
What it tests, as registered
Caffeine (6mg/kg); Placebo (Starch capsule); Sham (No Treatment)
Registered summary
This study aims to investigate the placebo (PLA) effect on physical performance across different sports disciplines in real-world, field-based settings. The study investigates how participant expectations and beliefs regarding caffeine (CAF) intake influence physical performance and psychomotor function outside the controlled laboratory environment. Healthy, physically active adults (n = 120) from diverse sports backgrounds will be randomly assigned to receive caffeine, placebo, or no intervention. The full summary is on the listing.
Where, as registered
No US site; Poland (1).
Not yet recruitingNCT07748416
The Effects of Acute Nitrate and Caffeine Co-ingestion on Discipline-Specific Exercise Performance.
No phase
Poznan University of Physical Education
About 112 people
Starts Oct 1, 2026 (estimated)
In plain words A study of caffeine in people 16 to 45, run by Poznan University of Physical Education. It plans to enroll about 112 people at 1 site, none in the US.
Who it lists and where
Who the trial lists, as registered
Lists people 16 to 45; healthy volunteers accepted. Conditions: Athletic Performance; Dietary Supplement; Iron Status.
Aged 18-45 years.
Minimum of 2 years of systematic HIFT/CrossFit/Hyrox training experience.
Performing >4 training sessions per week.
Ability to perform the HYROX Physical Fitness Test (P'F'T) and has participated in at least one official HYROX event.
12 more inclusion criteria and the exclusion criteria are on the listing.
The purpose of this study is to investigate the acute, separate, and combined ergogenic effects of dietary nitrate (beetroot juice, BJ) and caffeine (CAF) supplementation on discipline-specific athletic performance. The project employs a double-blind, randomized, placebo-controlled, four-arm crossover design. The full summary is on the listing.
Where, as registered
No US site; Poland (1).
Not yet recruitingNCT06780774
Investigating the Acute and Chronic Effects of a Supplement Containing Caffeine, Vitamins, Minerals and Botanical Extracts on Cognition, Sleep and Wellbeing, in Healthy Volunteers
No phase
Northumbria University
About 90 people
Starts Feb 24, 2025 (estimated)
In plain words A study of caffeine in people 18 to 75, run by Northumbria University. It plans to enroll about 90 people at 1 site, none in the US.
Who it lists and where
Who the trial lists, as registered
Lists people 18 to 75; healthy volunteers accepted. Conditions: Caffeine; Sleep; Cognitive Function; Wellbeing; Mood.
You self-assess yourself as being in good health.
You are aged 18-75 years at the time of giving consent.
English is your first language or are fluent in English.
The exclusion criteria are on the listing.
What it tests, as registered
Caffeine, Vitamins, Minerals and Botanical Blend; Placebo
Registered summary
The aim of the study is to investigate the acute and chronic effects of a supplement containing Caffeine, Vitamins, Minerals and Botanical extracts on cognitive function, sleep and wellbeing, in healthy volunteers. The study will follow a randomised, double-blind, placebo-controlled, crossover design. Participants will receive both treatments, and both study arms will include an acute testing visit (day 1) and a chronic testing visit (day 29). The full summary is on the listing.
Where, as registered
No US site; United Kingdom (1).
Not yet recruitingNCT07747545
Caffeine Intake and Periodontal Treatment Outcomes
No phase
Haoran Feng
About 90 people
Starts Aug 1, 2026 (estimated)
In plain words A study of caffeine in people 18 to 55, run by Haoran Feng. It plans to enroll about 90 people at 1 site, none in the US.
Who it lists and where
Who the trial lists, as registered
Lists people 18 to 55. Conditions: Periodontitis.
Adults aged 18 to 55 years.
Diagnosed with periodontitis according to the 2018 Classification of Periodontal and Peri-Implant Diseases and Conditions.
First visit for periodontal treatment and eligible for standard non-surgical periodontal therapy.
Willing and able to comply with the dietary intervention and scheduled follow-up visits.
2 more inclusion criteria and the exclusion criteria are on the listing.
What it tests, as registered
No Caffeine Intake; Low Caffeine Intake; Moderate Caffeine Intake
Registered summary
This study will explore whether caffeine intake can affect recovery after periodontal (gum) treatment. Periodontitis is a common gum disease caused by bacteria. Even after treatment, some people may still have ongoing inflammation or changes in oral bacteria. Researchers want to know if daily caffeine intake, such as from coffee, may help improve this condition. In this study, about 90 adults with periodontitis will receive standard periodontal treatment. Participants will be randomly assigned to one of three groups: no caffeine intake, low caffeine intake, or moderate caffeine intake. The full summary is on the listing.
Where, as registered
No US site; China (1).
Not yet recruitingNCT07748429
Placebo Effect on Cycling Performance: Laboratory Crossover Study
No phase
Poznan University of Physical Education
About 80 people
Starts Jan 1, 2027 (estimated)
In plain words A study of caffeine in people 20 to 35, run by Poznan University of Physical Education. It plans to enroll about 80 people at 1 site, none in the US.
Who it lists and where
Who the trial lists, as registered
Lists people 20 to 35; healthy volunteers accepted. Conditions: Physical Performance; Placebo Effect; Cognitive Performance.
Age between 20 and 35 years,
Healthy adults,
Regular physical activity, but not professional athletes,
Normal or corrected-to-normal vision,
1 more inclusion criterion and the exclusion criteria are on the listing.
What it tests, as registered
Caffeine (6mg/kg); Placebo (Starch capsule)
Registered summary
This study aims to determine the impact of the placebo (PLA) effect on physical and cognitive performance in a controlled laboratory setting. The study investigates how expectations and beliefs about substance intake (caffeine vs. placebo) interact with actual consumption to influence performance and physiological stress markers. Healthy adults (n = 80) will participate in four testing sessions using a randomized, double-blind, placebo-controlled crossover design. The full summary is on the listing.
Where, as registered
No US site; Poland (1).
Not yet recruitingNCT07456670
Caffeine for Infants Born at 28 to 34 Weeks Receiving Respiratory Support
Phase 2
Queen's University
About 62 people
Starts Apr 1, 2026 (estimated)
In plain words A Phase 2 study of caffeine in people 0 days to 28 days, run by Queen's University. It plans to enroll about 62 people at 1 site, none in the US.
Who it lists and where
Who the trial lists, as registered
Lists people 0 days to 28 days. Conditions: Preterm Birth; Caffeine; Neonatal Outcomes.
Infant born at a gestational age between 28+0 and 34+6 weeks.
Admitted to the Neonatal Intensive Care Unit (NICU) within the first 72 hours of life.
Requiring either invasive respiratory support (mechanical ventilation) or non-invasive respiratory support (e.g., CPAP, High Flow Nasal Cannula) within the first 72 hours of life.
Informed consent obtained from parent(s) or legal guardian(s).
The exclusion criteria are on the listing.
What it tests, as registered
Caffeine; Placebo
Registered summary
The goal of this pilot clinical trial is to test if it is possible to conduct a larger study on the use of caffeine in preterm infants who need help with their breathing. It will also look at whether caffeine helps these infants get healthy enough to leave the hospital sooner. The full summary is on the listing.
Where, as registered
No US site; Canada (1).
Not yet recruitingNCT07655245
Caffeine and Prophylactic Noradrenaline Requirement During Cesarean Delivery
No phase
Cairo University
About 62 people
Starts Jun 16, 2026 (estimated)
In plain words A study of caffeine in female participants 20 to 40, run by Cairo University. It plans to enroll about 62 people at 1 site, none in the US.
Who it lists and where
Who the trial lists, as registered
Lists female participants 20 to 40. Conditions: Spinal Hypotension; Vasopressor.
Full-term singleton pregnant (>37 weeks)
ASA II
undergoing elective cesarean section.
The exclusion criteria are on the listing.
What it tests, as registered
Caffeine (200 mg); Placebo
Registered summary
Spinal anesthesia is the preferred regional technique in obstetric practice because it provides high maternal satisfaction and eliminates the need for airway manipulation. Despite these advantages, it is frequently complicated by spinal anesthesia-induced hypotension , defined as a reduction in systolic blood pressure of more than 20% from baseline or an absolute SBP below 100 mmHg. The full summary is on the listing.
Where, as registered
No US site; Egypt (1).
Not yet recruitingNCT07873229
DDI Study of ECC0509 With Metformin, Midazolam, and Caffeine
Phase 1
Eccogene
About 40 people
Starts Nov 2026 (estimated)
In plain words A Phase 1 study of caffeine in people 18 to 65, run by Eccogene. It plans to enroll about 40 people at 1 site, none in the US.
Who it lists and where
Who the trial lists, as registered
Lists people 18 to 65; healthy volunteers accepted. Conditions: Steatohepatitis, Nonalcoholic; Osteo Arthritis.
Male or female between the ages of 18 and 65 years, inclusive, at the time of Screening.
Are healthy and in the opinion of the Investigator have an acceptable medical history (free from significant cardiac, pulmonary, gastrointestinal, hepatic, renal, haematological, neurological, infective, or psychiatric diseases as…
Has not consumed and agrees to abstain from taking any prescription drugs or non-prescription drugs for 7 days or 5 half-lives (whichever is longer) prior to first dose of trial treatment and continuing through end of the Treatment Period.
The exclusion criteria are on the listing.
What it tests, as registered
ECC0509; Metformin; Caffeine; Midazolam
Registered summary
This is a Phase 1, open-label, 2-part, fixed-sequence, single-center, two-period, drug-drug interaction trial in healthy adult participants to determine if ECC0509 administration at steady state affects the pharmacokinetics (PK) of metformin (a MATE1/2-K probe substrate), midazolam (a CYP3A4 probe substrate), and caffeine (a CYP1A2 probe substrate).
Where, as registered
No US site; Australia (1).
Not yet recruitingNCT06704711
Caffeine Mouth Rinse on Salivary Immunoglobulin A, Lactoferrin and A-Amylase Levels
No phase
University of Gaziantep
About 30 people
Starts Nov 15, 2024 (estimated)
In plain words A study of caffeine in male participants 19 to 26, run by University of Gaziantep. It plans to enroll about 30 people and lists no sites yet.
Who it lists and where
Who the trial lists, as registered
Lists male participants 19 to 26; healthy volunteers accepted. Conditions: Exercise Response.
Healthy men who have not had any previous injuries, do not have a chronic disease, do not use medication, do not smoke, and have played or are playing football as an amateur.
The exclusion criteria are on the listing.
What it tests, as registered
Caffeine 300 MG; Exercise; Placebo
Registered summary
The goal of this clinical trial is to investigate the effects of the mouth rinse form of caffeine (400 mg) on salivary lactoferrin, α-amylase and secretory immunoglobulin-a levels after incremental exercise in young amateur football players. The main questions it aims to answer are: * Caffeine in mouth rinse form increases salivary immunoglobulin a after incremental exercise * Caffeine in mouth rinse form increases salivary lactoferrin after incremental exercise * Caffeine in mouth rinse form increases salivary a-amylase after incremental exercise. The full summary is on the listing.
Where, as registered
No sites listed yet.
Not yet recruitingNCT06972108
CAffeine Use in Prolonged Oxygen Use in meConium aspIration Syndrome in Neonatal Outcomes (CAPUCINO)
Phase 2
University of Alberta
About 20 people
Starts Sep 1, 2026 (estimated)
In plain words A Phase 2 study of caffeine in people 10 days to 14 days, run by University of Alberta. It plans to enroll about 20 people and lists no sites yet.
Who it lists and where
Who the trial lists, as registered
Lists people 10 days to 14 days. Conditions: Meconium Aspiration Syndrome.
Infants born through meconium-stained amniotic fluid, and
Gestational age at or greater than 35+0 weeks at birth, and
Postnatal age of 10 to 14 days-old, and
Full enteral feeds either at semi-demand with a mix of gavage or oral feeds or at full-demand feeds by oral method, and
3 more inclusion criteria and the exclusion criteria are on the listing.
What it tests, as registered
Caffeine citrate; Saline (NaCl 0,9 %) (placebo)
Registered summary
When babies are stressed in the womb, they sometimes pass meconium in the amniotic fluid. When this happens, they may swallow the meconium-stained fluid into their lungs which may cause them to have poor oxygen levels and require resuscitation and significant breathing support in the early hours after birth. This is referred to as Meconium Aspiration Syndrome (MAS). Some babies may recover slowly and require breathing and/or oxygen support for days. The full summary is on the listing.
Where, as registered
No sites listed yet.
Not yet recruitingNCT07530185
Effects of L-Tyrosine and Caffeine on Performance in Elite Boxers
No phase
Inonu University
About 18 people
Starts Sep 2026 (estimated)
In plain words A study of caffeine in male participants 18 and older, run by Inonu University. It plans to enroll about 18 people at 1 site, none in the US.
Who it lists and where
Who the trial lists, as registered
Lists male participants 18 and older; healthy volunteers accepted. Conditions: Sports Performance.
Participants will complete six sessions, including one familiarization and baseline session followed by five experimental conditions: control (no supplementation), placebo, L-tyrosine, caffeine, and combined L-tyrosine plus caffeine. The experimental conditions will be performed in a randomized, counterbalanced crossover design with a washout period of at least 72 hours between sessions. The full summary is on the listing.
Where, as registered
No US site; Turkey (Türkiye) (1).
Not yet recruitingNCT06935214
The Repeatability of the Effect of Caffeine Supplementation on Submaximal Physiological Responses and Cycling Time Trial Performance
No phase
St. Mary's University, Twickenham
About 12 people
Starts May 1, 2025 (estimated)
In plain words A study of caffeine in male participants 18 to 35, run by St. Mary's University, Twickenham. It plans to enroll about 12 people and lists no sites yet.
Who it lists and where
Who the trial lists, as registered
Lists male participants 18 to 35; healthy volunteers accepted. Conditions: Caffeine.
To be considered for inclusion in the study, participants must be regular cyclists, between 18 and 35 years of age, capable of completing a 20 km cycling time trial at a minimum speed of 30 km/h (arbitrary inclusion criteria to ensure a…
The exclusion criteria are on the listing.
What it tests, as registered
Caffeine; Placebo; Caffeine
Registered summary
Recently, Grgic (2018) discussed the concept of responders and non-responders to caffeine supplementation highlighting the importance of the repeatability of results. However, the number of studies that have investigated this idea by repeating the same time-trial performance test multiple times with the same caffeine dose is sparse (Astorino et al., 2012; Del Coso et al., 2019). Furthermore, studies have shown that differences in the CYP1A2 genotype may account for some of the variation in time-trial performance (Guest et al., 2018). The full summary is on the listing.
Where, as registered
No sites listed yet.
Not yet recruitingNCT07873047
Acute Effects of Caffeine on Mitochondrial Function in Peripheral Blood Mononuclear Cells
No phase
Pontificia Universidad Catolica de Chile
About 12 people
Starts Sep 2026 (estimated)
In plain words A study of caffeine in people 18 to 65, run by Pontificia Universidad Catolica de Chile. It plans to enroll about 12 people and lists no sites yet.
Who it lists and where
Who the trial lists, as registered
Lists people 18 to 65; healthy volunteers accepted. Conditions: Energy Metabolism.
Healthy adults aged 18 to 65 years.
Body mass index between 18.5 and 27 kg/m².
Non-smokers.
Habitual caffeine intake of 200 mg/day or less.
2 more inclusion criteria and the exclusion criteria are on the listing.
What it tests, as registered
Caffeine (5 mg/kg); Placebo
Registered summary
This randomized, double-blind, placebo-controlled crossover study will evaluate the acute effects of caffeine consumption on substrate utilization, resting energy metabolism, and mitochondrial function in peripheral blood mononuclear cells (PBMCs) in healthy young adults. Approximately 10 healthy men and women aged 18 to 35 years will participate. Each participant will complete two experimental visits, receiving caffeine in one visit and placebo in the other, in randomized order. The two visits will be separated by a 48-hour washout period. The full summary is on the listing.