Green Coffee Extract
Summary
Green coffee extract slightly lowers blood pressure: a 2024 meta-analysis of 10 trials (563 people) found about 3/2 mmHg lower readings (grade C). Weight results are small and from poor-quality trials, about 1.3 kg in a 3-trial meta-analysis (grade D), and the best-known positive trial was retracted. Lab tests found many products mislabeled for chlorogenic acid and caffeine.
Key facts
- Extract of unroasted Coffea arabica or C. canephora beans, richer in chlorogenic acids than roasted coffee; it contains caffeine unless decaffeinated[1]
- 46–185 mg/day for blood pressure; 180–200 mg/day up to 800 mg/day in weight and metabolic trials, for 4 to 12 weeks[4][1][5]
- NIH ODS: only a few poor-quality weight trials; one heavily criticised trial was retracted by two of its three authors[1]
- In 23 products, chlorogenic acids ranged from none detected to 31%; two labeled 50% had none[7]
- None set; green coffee is a plant extract, not a nutrient[1]
- 3 graded human outcomes on this page
- October 10, 2026
How it works
ProposedChlorogenic acids, the main polyphenols in green coffee, may lower blood pressure by improving blood vessel function and may modestly reduce glucose absorption from the gut. In mice they curb fat accumulation. Roasting breaks down much of the chlorogenic acid.[1][3]
What the human research says
Human trials only, one row per outcome. The form column shows what each trial actually tested. Grades follow our evidence-grading policy.
At a glance: strongest evidence per outcome
| Outcome | Grade | Effect | Strongest evidence | Rows |
|---|---|---|---|---|
| Blood pressure | Grade C | Improved | Meta-analysis of 10 trials · n = 563 · 2024 | 2 rows |
| Body weight | Grade D | Improved | Meta-analysis of 3 trials · n = 103 · 2023 | 1 row |
Every graded row
| Outcome | Effect | Grade | Best evidence | PMID |
|---|---|---|---|---|
| Systolic and diastolic blood pressure | Improved | Grade C | Meta-analysis · n = 563 · 2024 Adults in 10 randomized trials Form: Green coffee bean extract (various) · Dose: Various; no dose-response found · Duration: Various Systolic pressure fell 2.95 mmHg and diastolic 2.15 mmHg versus control; heart rate did not change. Effects were larger in people with high blood pressure and absent in women. | 39368321 (opens PubMed)Source [3] |
| Blood pressure in mild hypertension (dose-response) | Improved | Grade C | RCT · n = 117 · 2005 Men with mild hypertension Form: Water-soluble green coffee bean extract · Dose: 46, 93 or 185 mg/day · Duration: 28 days Systolic pressure fell 3.2, 4.7 and 5.6 mmHg at 46, 93 and 185 mg versus 1.3 mmHg on placebo; the 93 mg (p<0.05) and 185 mg (p<0.01) doses differed significantly from placebo. | 16419643 (opens PubMed)Source [4] |
| Body weight | Improved | Grade D | Meta-analysis · n = 103 · 2023 Adults in 3 randomized trials Form: Green coffee bean extract containing chlorogenic acid · Dose: At least 500 mg/day · Duration: Various Body weight fell 1.30 kg more than control (95% CI −2.07 to −0.52), with no heterogeneity. | 37710316 (opens PubMed)Source [2] |
Forms
| Form | Elemental % | Absorption (human data) | GI tolerance | Studied for |
|---|---|---|---|---|
| Green coffee bean extract standardized to chlorogenic acids (often labeled 45–50%) | Varies[1][6] | No human absorption data in our sources.[1] | Headache and urinary tract infections were the adverse effects reported in weight trials; caffeine content adds stimulant effects.[1] | Weight trials (180–200 mg/day) and blood pressure trials |
| Decaffeinated green coffee extract | Varies[5][7] | No human absorption data in our sources.[5] | The 8-week metabolic syndrome trial abstract (800 mg/day) does not report adverse events.[5] | Metabolic syndrome trial (400 mg twice daily) |
Studied doses
Doses studied in human trials ranged from 46 mg/day (blood pressure) to 800 mg/day (decaffeinated extract in metabolic syndrome), for 4 to 12 weeks. Weight trials pooled by NIH ODS used 180–200 mg/day.[4][5][1]
Interactions
Published interactions only: each row cites a source. No row means none was found in our sources, not that a combination is safe.
Other supplements
- Other stimulantsNIH fact sheetGreen coffee extract contains caffeine unless decaffeinated; its stimulant effects depend on the total dose and on other stimulants taken with it.[1]
Who should be careful
- Caffeine sensitivity, pregnancy or heart rhythm problems
- Most extracts contain caffeine, and products labeled decaffeinated have tested above caffeine limits.[1][7]
- Liver problems
- Acute liver injury has been reported with multi-ingredient fat burners, including a green coffee bean product.[9]
- Low blood pressure or blood pressure medicines
- Green coffee extract lowered blood pressure by about 3/2 mmHg in trials; effects may add to medication.[3]
Talk to your pharmacist or clinician before starting a supplement, especially if you take prescription medicines.
Safety
Short-term trials report few problems, but product quality varies widely.
- Reported side effects
- Headache and urinary tract infections in weight trials; caffeine effects depend on dose and other stimulants.[1]
- Liver
- A Slovenian case series linked acute liver injury to fat burners, one of which contained green coffee beans; multi-ingredient products make cause hard to assign.[9]
How to read the label
- Label dose vs clinical doseBlood pressure trials used 93–185 mg/day of extract; weight trials 180–200 mg/day. Products often contain far more extract than this.[4][1]
- Chlorogenic acid claims are unreliableAcross 54 extracts, labels averaged 233 mg chlorogenic acids but testing found 157 mg; in a newer survey, two products labeled 50% had none.[8][7]
- Check the caffeineOnly 3 of 23 products declared caffeine, and none matched their labels; several "decaffeinated" products exceeded caffeine thresholds.[7]
Cost per studied dose, without the sales pitch
Compare any product you already have by the amount it delivers, not by capsule count or front-of-pack weight.
Cost per studied dose
Enter the price, servings and the amount per serving from your label.
Frequently asked questions
Does green coffee extract help weight loss?
Only slightly, in poor-quality trials: about 1.3 kg in a 3-trial meta-analysis. NIH ODS rates the evidence as low quality, and the best-known positive study was retracted.[2][1]
Does green coffee extract lower blood pressure?
Modestly. Across 10 trials, systolic pressure fell about 3 mmHg and diastolic about 2 mmHg, more in people with high blood pressure.[3]
How much green coffee extract is used in studies?
46–185 mg/day in blood pressure trials, 180–200 mg/day in weight trials and 800 mg/day of decaffeinated extract in one metabolic syndrome trial.[4][1][5]
Does green coffee extract contain caffeine?
Usually, unless decaffeinated, and labels are often wrong: some "decaf" products exceeded caffeine limits.[1][7]
Sources
- [1]Dietary Supplements for Weight Loss: Fact Sheet for Health Professionals (updated May 18, 2022). NIH Office of Dietary Supplements, 2022. fact-sheet
- [2]Chlorogenic acid in green bean coffee on body weight: a systematic review and meta-analysis of randomized controlled trials.. Syst Rev, 2023. meta-analysis
- [3]The effects of green coffee bean extract on blood pressure and heart rate: A systematic review and dose-response meta-analysis of randomized controlled trials.. Diabetes Metab Syndr, 2024. meta-analysis
- [4]Antihypertensive effect of green coffee bean extract on mildly hypertensive subjects.. Hypertens Res, 2005. RCT
- [5]Effects of green coffee extract supplementation on anthropometric indices, glycaemic control, blood pressure, lipid profile, insulin resistance and appetite in patients with the metabolic syndrome: a randomised clinical trial.. Br J Nutr, 2018. RCT
- [6]The use of green coffee extract as a weight loss supplement: a systematic review and meta-analysis of randomised clinical trials.. Gastroenterol Res Pract, 2011. meta-analysis
- [7]Chlorogenic acids and caffeine in commercial green coffee bean extract supplements: quantitative assessment and evidence of mislabelling.. Food Addit Contam Part A Chem Anal Control Expo Risk Assess, 2026. observational
- [8]Determination of Total Chlorogenic Acids in Commercial Green Coffee Extracts.. J Med Food, 2019. observational
- [9]Fat burner-induced acute liver injury: Case series of four patients.. Nutrition, 2018. observational
What changed
- First draft. Every PMID checked against NCBI E-utilities esummary (title and year taken from the record) and abstracts read for the cited rows.
- Adversarial review pass: every evidence row re-read against its PubMed abstract. Official source opened before citing: NIH ODS Dietary Supplements for Weight Loss fact sheet (May 18, 2022). The retracted 2012 trial (PMID 22291473, RetractionIn 25340633) is excluded; a 2019 meta-analysis (PMID 31398662) carries an erratum notice and was kept out. Industry ties: the 2005 dose-response trial's lead author is affiliated with Kao Corporation (PubMed affiliation); the 2023 weight meta-analysis was supported by a University of Phayao coffee R&D unit (PMC10503105). Retraction, expression-of-concern, erratum and withdrawn checks on all 8 PMIDs: none flagged. Page set indexable. Independent browser review (4 parallel reviewers, every evidence row checked against its abstract on the Vercel preview) found: decaffeinated-form tolerance wording (abstract silent on adverse events) and the Kao Corporation affiliation; fixed.