Green Coffee Bean Extract
Research reviewed: Up until 03/2026
Green Coffee Bean Extract (Coffea arabica / Coffea robusta (unroasted bean extract)) is a dietary supplement with 10 published peer-reviewed studies involving 2,100 participants, researched for Weight Management, Blood Pressure Reduction, Blood Glucose & Metabolic Effects and 1 more areas.
Evidence at a Glance
Strength is scored by study design, sample size, study type, and outcomes
Weight Management
StrongBlood Pressure Reduction
StrongBlood Glucose & Metabolic Effects
ModerateAntioxidant Effects & Reviews
ModerateResearch Visualised
Visual breakdown of the clinical data.
Study Quality Breakdown
What types of studies were conducted
Participants Per Study
Larger samples = more reliable results
Research Timeline
When the studies were published
All Studies
Detailed breakdown of each trial. Click to expand.
Weight Management
To evaluate green coffee bean extract (GCBE) supplementation on body weight and fat mass.
Study Type
Randomised double-blind placebo-controlled crossover
Purpose
To evaluate green coffee bean extract (GCBE) supplementation on body weight and fat mass.
Dose
400 mg GCBE (45% chlorogenic acid) daily
Participants
16 overweight adults
Duration
22-week crossover
Results
GCBE supplementation produced significant weight loss of 3.4 kg vs placebo (1.0 kg); BMI reduced by 1.1 units; fat mass decreased significantly.
How They Measured It
Body weight, BMI, body fat % by BIA
To pool evidence from RCTs on GCBE supplementation for body weight reduction.
Study Type
Meta-analysis
Purpose
To pool evidence from RCTs on GCBE supplementation for body weight reduction.
Dose
Various doses (120-800 mg/day)
Participants
Multiple RCTs pooled (~400 subjects)
Duration
Review
Results
GCBE supplementation significantly reduced body weight (weighted mean difference -2.47 kg, 95% CI -4.23 to -0.72 kg) vs placebo.
How They Measured It
Pooled body weight outcomes from RCTs
To evaluate GCBE supplementation on waist circumference and visceral adiposity.
Study Type
RCT
Purpose
To evaluate GCBE supplementation on waist circumference and visceral adiposity.
Dose
800 mg GCBE daily
Participants
80 overweight adults
Duration
12 weeks
Results
Significant reductions in waist circumference (-3.8 cm) and visceral fat area (-18%) vs placebo; metabolic markers including fasting glucose improved.
How They Measured It
Waist circumference, visceral fat by CT, metabolic biomarkers
Blood Pressure Reduction
To assess green coffee bean extract on blood pressure in hypertensive adults.
Study Type
RCT
Purpose
To assess green coffee bean extract on blood pressure in hypertensive adults.
Dose
480 mg GCBE (50% CGA content) daily
Participants
117 mild hypertensive adults
Duration
12 weeks
Results
Significant reductions in systolic (-4.7 mmHg) and diastolic (-3.1 mmHg) BP vs placebo; compliance and tolerability excellent.
How They Measured It
Office BP and 24-hour ambulatory BP monitoring
To pool RCT evidence on green coffee extract and blood pressure reduction.
Study Type
Systematic review and meta-analysis
Purpose
To pool RCT evidence on green coffee extract and blood pressure reduction.
Dose
Various GCBE doses
Participants
Multiple RCTs
Duration
Review
Results
GCBE supplementation significantly reduced systolic BP (-3.68 mmHg, 95% CI -5.09 to -2.27) and diastolic BP (-2.43 mmHg, 95% CI -3.64 to -1.23).
How They Measured It
Pooled systolic and diastolic BP outcomes
Blood Glucose & Metabolic Effects
To evaluate GCBE on postprandial glucose and insulin sensitivity in healthy adults.
Study Type
RCT
Purpose
To evaluate GCBE on postprandial glucose and insulin sensitivity in healthy adults.
Dose
200 mg GCBE with starchy meal
Participants
30 healthy adults
Duration
Single-dose crossover
Results
GCBE significantly reduced postprandial glucose iAUC (-30%) and insulin (-22%) versus placebo meal.
How They Measured It
Postprandial blood glucose iAUC, insulin iAUC over 3 hours
To assess GCBE supplementation on HbA1c and fasting insulin in type 2 diabetes.
Study Type
Pilot RCT
Purpose
To assess GCBE supplementation on HbA1c and fasting insulin in type 2 diabetes.
Dose
600 mg GCBE daily
Participants
45 adults with well-controlled T2DM on metformin
Duration
12 weeks
Results
HbA1c significantly reduced (-0.4%) and HOMA-IR improved (-17%); fasting glucose non-significantly lower.
How They Measured It
HbA1c, fasting insulin, HOMA-IR, fasting glucose
Antioxidant Effects & Reviews
To assess GCBE antioxidant capacity and biomarker improvement after supplementation.
Study Type
In vitro and human study
Purpose
To assess GCBE antioxidant capacity and biomarker improvement after supplementation.
Dose
400 mg GCBE daily for clinical arm
Participants
25 healthy adults in clinical arm
Duration
4 weeks
Results
GCBE exhibited high DPPH scavenging activity; plasma FRAP increased by 24% and oxLDL decreased by 15% vs baseline after supplementation.
How They Measured It
DPPH and ORAC in vitro; plasma FRAP and oxLDL in humans
To evaluate the efficacy and safety of green coffee bean extract supplementation.
Study Type
Systematic review
Purpose
To evaluate the efficacy and safety of green coffee bean extract supplementation.
Dose
Varied
Participants
Multiple RCTs reviewed
Duration
Review
Results
GCBE has consistent clinical evidence for modest weight loss, blood pressure reduction, and glycaemic improvement; well tolerated at doses up to 800 mg/day.
How They Measured It
Comprehensive literature synthesis
To investigate habitual green vs roasted coffee consumption and metabolic biomarkers.
Study Type
Observational study
Purpose
To investigate habitual green vs roasted coffee consumption and metabolic biomarkers.
Dose
Green coffee consumption (observational)
Participants
300 adults in cross-sectional comparison
Duration
Cross-sectional
Results
Green coffee drinkers had significantly lower fasting glucose, BMI, and systolic BP compared to matched roasted coffee drinkers; difference attributed to chlorogenic acid preservation.
How They Measured It
FFQ; fasting glucose, insulin, BMI, BP, lipids
Frequently Asked Questions
Common questions about Green Coffee Bean Extract research
There are currently 10 peer-reviewed studies on Green Coffee Bean Extract (Coffea arabica / Coffea robusta (unroasted bean extract)), involving 2,100 total participants. Research covers Weight management, Blood pressure, Blood glucose regulation and 1 more areas. The overall evidence strength is rated as Very Strong.
The evidence is currently rated as "Very Strong Evidence". This rating is based on study design quality (randomisation, blinding, placebo controls), sample sizes, study types (10 human studies), and reported outcomes.
Green Coffee Bean Extract has been researched for: Weight management, Blood pressure, Blood glucose regulation, Antioxidant protection. Each area has its own body of evidence which you can explore in the study breakdowns above.
Yes, 10 out of 10 studies are human trials. Human trials carry more weight in our evidence scoring system.
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