Green Coffee Bean Extract
An extract from unroasted (green) coffee beans, standardised for a compound called chlorogenic acid. Distinct from regular roasted coffee — roasting destroys most of the chlorogenic acid. Widely marketed for weight loss. The current evidence is limited and short-term, with more promising data on blood sugar and blood pressure than on weight loss itself.
Quick read · 3 min
- •Evidence: Weak — limited or inconsistent trial data
- •The evidence base is limited.
- •Generally considered safe at standard doses for short-term use.
- •Prescription weight loss drugs produce 7–21% weight loss in trials. Most supplements in this category produce less than 2 kg.
Based on clinical trials · No rankings · Every claim linked to source
Last reviewed: March 2026
How it works
Chlorogenic acid is thought to reduce how quickly your gut absorbs glucose from food, and may reduce fat accumulation in the liver. Green coffee bean extract also contains caffeine, which varies by product and contributes some thermogenic (calorie-burning) effect. The chlorogenic acid and caffeine effects likely work together.
What the evidence shows
The evidence base is limited. A review by the NIH Office of Dietary Supplements found only limited clinical evidence supporting potential short-term (under 12 weeks) weight loss effects. The available trials are generally small, short, and of low methodological quality. There is more consistent — though still modest — evidence for effects on blood sugar levels and blood pressure. Green coffee bean extract should not be counted on as a reliable weight loss strategy based on current evidence.
Safety
Generally considered safe at standard doses for short-term use. The caffeine content varies significantly between products — sensitive individuals may experience insomnia, anxiety, increased heart rate, or raised blood pressure. People already consuming significant caffeine (coffee, energy drinks) should account for the additional caffeine in the extract. Not suitable for people with certain heart conditions or anxiety disorders.
Community insights
These are personal experiences shared in public online communities — not medical advice.
“The caffeine content varies enormously between brands. If you're caffeine-sensitive, check the standardisation on the label.”
“Most of the evidence that got people excited about this was later shown to have data problems. The real-world effect is probably very small.”
Common questions
After reading this page, most people compare this with other supplements, look at prescription options, or check what they can do today without a prescription.