GCBest® (Green Coffee Bean Extract)

GCBest® is a green (unroasted) coffee bean extract standardized for chlorogenic acid, the polyphenol largely lost during roasting. In small, short-term trials green coffee extract has produced modest weight reductions of around 1 kg.

GCBest is researched primarily for Weight Management. A pooled analysis of three small, short-term trials (103 adults in total) found green coffee extract providing at least 500 mg/day of chlorogenic acid reduced body weight by about 1.3 kg versus control.

The clinically studied dose is The pooled trials used green coffee extract providing at least 500 mg/day of chlorogenic acid. Products are commonly sold at 200 to 400 mg/day of extract. Always follow the product label and check with a healthcare provider for personal advice.

Side effects and cautions reported for GCBest include: Generally well-tolerated. Contains caffeine; can cause jitteriness or sleep trouble. It may also interact with some medications. GCBest is not right for everyone, so check with a healthcare provider first if you are pregnant or breastfeeding, have a medical condition, or take prescription medication.

Possible interactions include: Stimulant medications — caffeine content may add effects; use caution. Diabetes medication — monitor blood sugar. If you take prescription medication, check with a pharmacist or doctor before using it.

NutraSmarts rates the evidence for GCBest as Limited (2 out of 5). It is backed by 1 study summary and 1 cited reference summarized on this page. A higher rating reflects more, larger, and better-designed human studies.