Paraxanthine (1,7-dimethylxanthine)

Q: What is paraxanthine?

The main compound the body makes from caffeine, with trade press citing about 70% of a caffeine dose. A synthetic version is sold as a stimulant ingredient.

Q: Is paraxanthine better than caffeine?

Not proven. One small trial found fewer perseverative errors than caffeine after a run, but an independent rowing trial found no clear stand-alone performance gain. Neither tested long-term use.

Q: What doses were studied?

Single doses of 50 to 300 mg, mostly 200 mg, and 50, 100 or 200 mg daily for 7 days. These are research doses, not advice.

Q: Does paraxanthine help sleep?

Not shown. In 14 rowers, paraxanthine alone had more favourable self-rated sleep than caffeine, but this was a subjective rating in a small study.

Q: Is paraxanthine regulated as safe?

The maker self-affirmed GRAS status in 2021, which is not an FDA review, and we did not find an FDA no-questions letter. In the EU synthetic paraxanthine is a novel food; the public summary describes an ongoing application, and the applicant itself says it is not recommended for children, pregnancy or breastfeeding.

Also called 1,7-dimethylxanthine, enfinity paraxanthine, caffeine metabolite, PX, paraxanthine nootropic.

Best grade D across 5 graded outcomes Other Last checked Oct 25, 2026

The short answer

From 9 sources

Paraxanthine is a caffeine-like stimulant with a handful of small, short, manufacturer-linked trials. Three crossover trials in 12 to 21 adults found some attention and memory test gains at 200 mg, but an independent 2026 rowing study found no clear standalone benefit. Long-term human safety data are missing.

Every graded outcome on this page

5 rows · line = participants

Grade DResting energy expenditure, hunger and fat breakdownEnergy expenditure and appetiten 21
Grade D2000 m rowing time trial and sleep qualityRowing performance and sleepn 14
Grade DCognitive test performance after one doseAttention and memory testsn 13
Grade DCognitive tests at 50, 100 and 200 mg, acute and 7 daysDose and 7-day tolerancen 12
Grade DCognition before and after a 10 km runPost-exercise cognitionn 12
2 more graded outcomes, in the evidence chapter

Key facts

What it is: 1,7-dimethylxanthine, the main caffeine metabolite in humans (trade press cites about 70% of caffeine being converted to it)^7,8
Cognition trials: Acute 200 mg lowered card-sorting errors at hour 6 in 13 adults; 12 trained runners made fewer perseverative errors than with caffeine after a 10 km run^1,3
Energy use: 200 mg raised energy expenditure compared with placebo over the 3-hour measurement in 21 adults, and hunger ratings rose with placebo but not with 200 mg⁴
Independent trial: In 14 rowers, 200 mg paraxanthine alone showed no clear performance gain; caffeine plus paraxanthine was the only condition faster than placebo⁵
Regulatory: Self-affirmed GRAS by the ingredient maker (2021); no FDA no-questions letter was found; EU novel food application pending at the time of the cited summary^8,9

What it is

Paraxanthine is the main metabolite the body makes from caffeine, and a synthetic form is now sold as a stimulant ingredient intended as a caffeine alternative.

How it works

Proposed

Paraxanthine is a methylxanthine described as having stimulant pharmacology similar to caffeine, whose main known target is adenosine receptor blocking. None of the human trials cited here measured receptor effects; they measured test performance, energy expenditure and side-effect ratings, so how paraxanthine acts in people is inferred from caffeine.⁷

Forms

Form

The form on this page
Form	Elemental %	Absorption (human data)	GI tolerance	Studied for
Paraxanthine capsules or powder (synthetic)	Varies⁷Not applicable (single molecule; dosed by milligrams of paraxanthine)	Formed in the body from caffeine through shared liver metabolism pathways; no human absorption study of the synthetic ingredient was found in the sources reviewed.⁹	No significant side-effect or clinical chemistry differences from placebo over 7 days of daily 50, 100 or 200 mg in 12 adults; no long-term human data.²	Single 100 to 300 mg doses for energy expenditure; 50 to 200 mg for cognition; 200 mg before exercise

What the human research says

Human trials only, one row per outcome. The form line shows what each trial actually tested. Grades follow our evidence-grading policy.

Trial map

5 graded outcomes, largest study first

5 graded outcomes: 2 improved, 3 mixed. The largest, a 2024 crossover trial of 21 people on resting energy expenditure, hunger and fat breakdown, found mixed results.

By ageBy sizeTable

AgeAll ages

Bar: the ages a study enrolled (running to the edge when it states no upper or lower limit). Dot: only a mean age, counted as near your age within 5 years. Tick: the mean age inside a range.

22000 m rowing time trial and sleep quality: mixed, mean age 21.6

5Cognitive tests at 50, 100 and 200 mg, acute and 7 days: mixed, mean age 22.7

1Resting energy expenditure, hunger and fat breakdown: mixed, mean age 26

3Cognitive test performance after one dose: improved, ages not stated

4Cognition before and after a 10 km run: improved, ages not stated

1Resting energy expenditure, hunger and fat breakdown

Mixed · Grade D · Crossover RCT, 21 people, 2024

Adults (13 men, 8 women), average age 26

Dose, result and source

Every graded outcome on this page, largest study first
Outcome	Found	People	Study	Who was studied
Resting energy expenditure, hunger and fat breakdown	Mixed	21	Grade D · Crossover RCT, 2024	Adults (13 men, 8 women), average age 26
2000 m rowing time trial and sleep quality	Mixed	14	Grade D · Crossover RCT, 2026	Male university-level rowers
Cognitive test performance after one dose	Improved	13	Grade D · Crossover RCT, 2021	Healthy adults (male and female)
Cognition before and after a 10 km run	Improved	12	Grade D · Crossover RCT, 2024	Trained runners
Cognitive tests at 50, 100 and 200 mg, acute and 7 days	Mixed	12	Grade D · Crossover RCT, 2021	Healthy male and female volunteers aged about 23

Every graded row

5 rows

Form tested

Showing 5 of 5 outcomes. Human trials only.

Grade DResting energy expenditure, hunger and fat breakdownEnergy expenditure and appetiteHigher resting energy expenditure at 200 mg for 3 hoursCrossover RCT
n 21 · 2024

Mixed 200 mg raised energy expenditure compared with placebo (all p < .05), and hunger ratings rose with placebo but not with 200 mg. Blood pressure did not change. Heart rate was lower with 100 mg than placebo at 60 and 180 minutes. Free fatty acids rose with 300 mg (p = .002); glycerol did not change.

Design: Crossover RCT, n = 21, 2024
Population: Adults (13 men, 8 women), average age 26
Form: Paraxanthine (enfinity)
Dose: 100, 200 or 300 mg (versus placebo)
Duration: Single dose, measured over 180 minutes
Source: Reference 4 · PubMed 38745415 (opens PubMed)

Grade D2000 m rowing time trial and sleep qualityRowing performance and sleepNo clear stand-alone performance benefit; sleep ratings were more favourable than with caffeineCrossover RCT
n 14 · 2026

Mixed Caffeine plus paraxanthine was faster than placebo (p = 0.044, Cohen's d = 0.30). Neither compound alone showed clear evidence of improvement. Conditions with caffeine were linked to poorer self-rated sleep; paraxanthine alone had more favourable sleep scores.

Design: Crossover RCT, n = 14, 2026
Population: Male university-level rowers
Form: Paraxanthine
Dose: 200 mg paraxanthine, 200 mg caffeine, both, or placebo
Duration: Single dose before each 2000 m trial
Source: Reference 5 · PubMed 41918248 (opens PubMed)

Grade DCognitive test performance after one doseAttention and memory testsSome test gains at hour 6; many results were trendsCrossover RCT
n 13 · 2021

Improved Card-sorting errors fell by 4.7 (p = 0.04) and perseverative errors by 2.2 (p = 0.03) versus placebo at hour 6. Vigilance reaction time held up better than with placebo at 2 and 4 hours. Several other measures showed trends only (p = 0.05 to 0.07).

Design: Crossover RCT, n = 13, 2021
Population: Healthy adults (male and female)
Form: Paraxanthine (enfinity)
Dose: 200 mg once
Duration: Single dose, tested hourly for 6 hours
Source: Reference 1 · PubMed 34836235 (opens PubMed)

Grade DCognitive tests at 50, 100 and 200 mg, acute and 7 daysDose and 7-day toleranceScattered test differences, more consistent at 100 and 200 mg; no clinical chemistry or side-effect differencesCrossover RCT
n 12 · 2021

Mixed The Sternberg 4-letter reaction time tended to differ among groups (p = 0.06), and mean changes from baseline differed from placebo on card sorting, Go/No-Go accuracy and Sternberg measures. The authors reported more consistent effects at 100 and 200 mg than at 50 mg. No significant differences in clinical chemistry panels or in the frequency or severity of reported side effects.

Design: Crossover RCT, n = 12, 2021
Population: Healthy male and female volunteers aged about 23
Form: Paraxanthine (enfinity)
Dose: 50, 100 or 200 mg once daily (versus placebo)
Duration: Acute test over 6 hours, then once daily for 7 days
Source: Reference 2 · PubMed 34960030 (opens PubMed)

Grade DCognition before and after a 10 km runPost-exercise cognitionFewer perseverative errors than caffeine after a run, in one small crossoverCrossover RCT
n 12 · 2024

Improved After the run, perseverative errors (PAR rules) were lower with paraxanthine than with caffeine (-26.9%, p = 0.026), and mean reaction time across vigilance trials was faster than with placebo (-23.2%, p = 0.029) and than with paraxanthine plus caffeine (-29.6%, p = 0.006). Adding caffeine to paraxanthine gave no additional benefit. The authors found no evidence of adverse effects on stimulant side-effect ratings or clinical blood markers.

Design: Crossover RCT, n = 12, 2024
Population: Trained runners
Form: Paraxanthine (enfinity)
Dose: 200 mg paraxanthine, 200 mg caffeine, both, or placebo (single dose)
Duration: Single dose, 60 minutes before a 10 km treadmill run
Source: Reference 3 · PubMed 38725238 (opens PubMed)

What the numbers add up to

Each point is worked out from the data and the sources numbered on this page, with the arithmetic shown under it. It adds no new data and is not medical advice.

The trials are small, short and mostly sponsor-linked

Four of the five trials list authors affiliated with the ingredient's maker, and the groups ranged from 12 to 21 people. The one apparently independent trial found no clear stand-alone benefit.^1,2,3,5

You already make some from caffeine

Paraxanthine is the main metabolite of caffeine in humans, with trade press citing about 70% of caffeine converted to it, so coffee drinkers already have it circulating. Supplementing it is a different exposure, and its long-term effects in people are unstudied.^7,8,9

Rat studies found no toxic effects at the doses tested

One 90-day rat study found no toxic effects up to 300 mg/kg a day, the highest dose tested. A second 90-day rat study found no toxicity at 185 mg/kg, with two deaths in the high-dose caffeine group. Both packages found no mutagenicity or genotoxicity in the tests reported. Animal data do not establish human safety.^6,7

Studied doses

Doses used in research, shown against the official limits. They describe the studies, not a recommendation for you.

Studied doses in research, not advice. These are amounts used in research, not personal advice. Your clinician or pharmacist can say what fits you.

Doses studied in human trials

Doses studied in human trials ranged from single 50 to 300 mg doses (200 mg in most trials) up to 50, 100 or 200 mg once daily for 7 days. All studies were short and four of the five were linked to the ingredient's maker. These are research doses, not advice.^1,2,3,4,5

Interactions and safety

Published interactions only: each row cites a source. No row means none was found in our sources, not that a combination is safe.

What Paraxanthine meets

1 cited row

Medicines 0

No medicine rows in our sources.

Paraxanthine0 medicines · 1 supplement

Supplements and foods 1

Measured in a human study

Interactions

1 agent

Published interactions, grouped by kind
Agent	What the source says	Evidence
Other supplements1
Caffeine and other stimulants	In the 10 km study adding caffeine to paraxanthine gave no extra cognitive benefit; in the rowing study the combination was the only condition faster than placebo. Stacking stimulants has not been tested for safety, and combined stimulant load is an inference from shared mechanism.^3,5	RCT

Check with what you take

Kept on this device only

Add what you take. We list every interaction our evidence profiles cite between Paraxanthine and your picks, and between your picks.

Add a supplement or medicine

Most cited:

Add a supplement or medicine you take to check it against Paraxanthine.

Starting from one medicine? The interaction checker rates how serious each pair is, on a curated list of 19 entries for 11 medicines. This cabinet has no severity rating: it lists every interaction row our supplement pages cite.

Who should be careful

4 groups

Caffeine sensitivity, anxiety, palpitations or insomnia: Paraxanthine acts on the same receptors as caffeine and no trial tested it in people who react badly to caffeine. In the rowing study, the conditions without caffeine had better self-rated sleep, but that was a subjective measure in 14 men.^5,7
Heart conditions, high blood pressure or stimulant medicines: Trials were in healthy adults for hours to 7 days. A 300 mg single dose raised free fatty acids, and no study followed blood pressure or heart rhythm over months. No interaction trial with stimulant, blood-pressure or heart-rhythm medicines was found; because paraxanthine resembles caffeine, additive effects are a reasonable concern but are an inference, not a finding.^2,4
Pregnancy, breastfeeding and children: No human data were found. Caffeine intake limits apply to caffeine itself; paraxanthine has not been assessed for these groups.⁷
Competitive athletes: Check the current prohibited list and tested-product certification for your sport before use; this page did not verify anti-doping status.⁵

How to read the label

What to check on the Supplement Facts panel.

How to read the label

3 checks

Count milligrams, not blends

Studied doses were 50 to 300 mg of paraxanthine alone. Pre-workout blends often combine it with caffeine and other stimulants, so the trial results do not carry over.^3,4

Look for the ingredient brand

Most trials used one branded synthetic ingredient. Labels that do not name the source or purity give less to check.^1,2

Add up all your stimulants

Coffee, energy drinks and pre-workouts count too. No trial studied heavy combined stimulant intake with paraxanthine.^3,5

Label X-RayPhotograph a bottle's Supplement Facts panel and see each line, paraxanthine (1,7-dimethylxanthine) included, beside the doses and forms the trials used

Frequently asked questions

Short answers to common questions; the numbers link to the sources below.

Common questions

5 answers

What is paraxanthine?

The main compound the body makes from caffeine, with trade press citing about 70% of a caffeine dose. A synthetic version is sold as a stimulant ingredient.^8,9

Is paraxanthine better than caffeine?

Not proven. One small trial found fewer perseverative errors than caffeine after a run, but an independent rowing trial found no clear stand-alone performance gain. Neither tested long-term use.^3,5

What doses were studied?

Single doses of 50 to 300 mg, mostly 200 mg, and 50, 100 or 200 mg daily for 7 days. These are research doses, not advice.^2,4

Does paraxanthine help sleep?

Not shown. In 14 rowers, paraxanthine alone had more favourable self-rated sleep than caffeine, but this was a subjective rating in a small study.⁵

Is paraxanthine regulated as safe?

The maker self-affirmed GRAS status in 2021, which is not an FDA review, and we did not find an FDA no-questions letter. In the EU synthetic paraxanthine is a novel food; the public summary describes an ongoing application, and the applicant itself says it is not recommended for children, pregnancy or breastfeeding.^8,9

Sources

9 sources: trial abstracts, NIH fact sheets and reference databases. Numbers in the text link here.

Sources cited on this page

9 sources

1Acute Paraxanthine Ingestion Improves Cognition and Short-Term Memory and Helps Sustain Attention in a Double-Blind, Placebo-Controlled, Crossover Trial.Crossover RCT Nutrients, 2021 · PMID 34836235
2Dose-Response of Paraxanthine on Cognitive Function: A Double Blind, Placebo Controlled, Crossover Trial.Crossover RCT Nutrients, 2021 · PMID 34960030
3Paraxanthine provides greater improvement in cognitive function than caffeine after performing a 10-km run.Crossover RCT J Int Soc Sports Nutr, 2024 · PMID 38725238
4A Dose-Response Study to Examine Paraxanthine's Impact on Energy Expenditure, Hunger, Appetite, and Lipolysis.Crossover RCT J Diet Suppl, 2024 · PMID 38745415
5Comparative effects of caffeine and paraxanthine on rowing performance and sleep quality: a randomized crossover study.Crossover RCT J Int Soc Sports Nutr, 2026 · PMID 41918248
6An assessment of mutagenicity, genotoxicity, acute-, subacute and subchronic oral toxicity of paraxanthine (1,7-dimethylxanthine).Animal study Food Chem Toxicol, 2021 · PMID 34597720
7Paraxanthine safety and comparison to caffeine.Animal study Front Toxicol, 2023 · PMID 36818692
8Ingenious Ingredients self-affirms GRAS status for paraxanthine ingredientDatabase NutraIngredients-USA, 2021 · nutraingredients.com
9Public summary: novel food application for paraxanthine (ENFINITY), ongoing applicationsDatabase European Commission, Food Safety, 2023 · food.ec.europa.eu

What changed

Every dated change to this page: what changed, who made it and why.

Change log

2 entries

Dated changes to this page
Date	Change	Who and why
Oct 25, 2026evidence	Adversarial review: the 13-person acute cognition crossover regraded C to D (a single very small trial, per the grading rubric); sponsor ties confirmed from the PubMed conflict-of-interest statements and affiliations (four trials list Ingenious Ingredients or Increnovo authors; the 2026 rowing trial reports no conflicts); EU summary re-opened and its line on children, pregnancy and breastfeeding confirmed.	Writer: Kymata Health EditorialTrigger: adversarial review
Oct 17, 2026all	Initial editorial evidence review. Every PMID checked against NCBI E-utilities esummary (title, year, journal) and each cited abstract read; figures taken from the abstracts. Regulatory status from trade press and the EU novel-food public summary; no FDA GRAS notice located.	Writer: Kymata Health EditorialTrigger: new page

Supplement & Nutrient Encyclopedia. Educational information only; it is not medical advice and does not replace a clinician. Dietary supplements are not intended to diagnose, treat, cure or prevent any disease. Statements about supplements have not been evaluated by the FDA.

Paraxanthine (1,7-dimethylxanthine)

Medicines 0

Supplements and foods 1

CaffeineCaffeine page