phone: 03 5241 6129

follow us:

Green Coffee Bean Extract for Weight Loss?

Green Coffee Bean Extract for Weight Loss?

For those of you who’re interested in shedding a few pounds–whether your motivation comes from wanting to improve your overall health or simply look better at the beach this summer, the coffee bean just keeps giving and giving…

Previously, I wrote about how coffee mannans (coffee mannooligosaccharides) which are basically an indigestible component found in coffee beans helped men but not women lose a modest amount of weight.

green coffee bean

More recently, researchers from the chemistry department at the University of Scranton have looked at the weight loss benefits associated with supplementation with green coffee bean extract [1].  Specifically, the product, GCA® was provided by Applied Food Sciences Inc (Austin, TX).  The study authors did not disclose any conflicts of interest and apparently did not seem to indicate that this manufacture paid for the study itself.


Study Design:

The researchers utilized a randomized, double-blind, placebo-controlled, linear dose, crossover design to evaluate the safety and efficacy of Green Coffee Bean extract at promoting weight loss in overweight subjects.

The study was only modestly powered with a total of 16 subjects included.

Green Coffee Bean Extract

The supplement was provided by the aforementioned manufacturer in Austin TX.  Two dosages (1050 mg, 700 mg) were compared with placebo.  Each dosage was taken for a duration of six weeks with a two-week washout period in between.

Did it work?

The results of this particular study if replicated in subsequent trials are pretty staggering:

Significant reductions were observed in body weight (−8.04 ± 2.31 kg), body mass index (−2.92 ± 0.85 kg/m2), and percent body fat (−4.44% ± 2.00%), as well as a small decrease in heart rate (−2.56 ± 2.85 beats per minute), but with no significant changes to diet over the course of the study. Importantly, the decreases occurred when subjects were taking GCA. Body mass index for six subjects shifted from preobesity to the normal weight range (<25.00 kg/m2).

Note that these numbers are from baseline to the end of the 22 week study.  Overall, there was roughly a net 10% reduction in both body weight and BMI with a 15.8% reduction in body fat.

What’s somewhat interesting is that if you look at the weight loss data (figure 1), the group that started with placebo appears to have lost most of its weight during this phase.

Though the authors did not report any side effects from GCA extract nor any participants withdrawing from the study, there was a non-statistically significant increase in blood pressure of just under 5 mmhg from the beginning to the end of the trial (table 1).

The authors noted in their discussion:

“Attrition rates averaged 30%–40%. Compared with placebo, orlistat reduced weight by 2.9 kg (2.9%) sibutramine by 4.2 kg (4.3%), and rimonabant by 4.7 kg (4.1%). BMI reductions were 1.0 with orlistat and 1.5 with sibutramine. Lack of adherence to treatment seems to be a major factor limiting the efficacy and effectiveness of antiobesity drugs.(ref) Thus the GCA with a weight loss of 8 kg (10.5%) and a BMI reduction of almost 3 makes the product superior to the prescription drugs.”

Granted that these claims seem a little extravagant given the number of participants included in this study (16), these initial findings suggest that Green Coffee Bean extract could be a very promising weight loss supplement.

Though it’s not currently understood how GCA extract promotes weight loss, the study authors speculated that one component, chlorogenic acid, may alter glucose absorption or possibly activate fat metabolism.


  1. Vinson JA, Burnham BR, Nagendran MV.  Randomized, double-blind, placebo-controlled, linear dose, crossover study to evaluate the efficacy and safety of a green coffee bean extract in overweight subjects.  Diabetes Metab Syndr Obes. 2012;5:21-7. Epub 2012 Jan 18.


  • James

    Do you have any opinion on Green Coffee Extract and its combination with protein powders? There are several new products that utilise GCA in blends marketed as 'thermogenic proteins'. Thanks

    • Jarret Morrow, M.D.

      James, both products are very useful for achieving weight loss goals. I'd personally prefer to simply take a green coffee bean extract supplement separate from a whey protein product. There's really no added benefit to taking a product that contains both especially if the dosing of the GCBE isn't included at the proper dosage.

  • Joe

    Jarret, good review. When I looked at the Texas study, I noticed that it was actually conducted in India. Wonder why? Most of the green coffee bean research also have very small sample sizes. A 2011 meta analysis on green coffee bean only found 3 studies (out of 2000) that were considered high quality. This is definitely a product that needs more - and better - research.

    • Jarret Morrow, M.D.

      Joe, you're right there isn't much published research about this supplement. Some of the other studies focus on outcomes like blood pressure instead of weight loss. At the same time, there's already better quality data about GCBE than there is for raspberry ketone. Though it's not scientific, I've already anecdotally heard form several people who've achieved some impressive weight loss results with this supplement.

    • maldita

      all your comment was true,i want to take this tea but i do not know where can i buy this..somebody can tell me where shall im going to buy this?im a pilipina girl and i leave here in philippines too...THANK YOU

  • Richard

    I have problems with my colon. Is this safe for me?

  • Ron L. Goddard

    Dr.Morrow,recent back surgery not only prevents me from getting excersize, but also has caused me to gain 60 lbs. Can I loose that extra weight by taking this product? I am 72 yrs. old.

  • Dr. Osso Buco

    Green coffee bean extracts is used for losing the weight. This helps the peoples to lose their weight and remain healthy in the life. By using this the extra gained weight can lose and remain fit in the life.

  • akmar180876

    Jarret hv you ever heard or do research on marine collagen.currently this product really famous but nobody study or comment on its bad side

  • Terry

    Where can one purchase these Green Coffee supplements that actually were said to produce results. Do a search for Green Coffee supplements and you get thousands of results (all promising to be THE one that works). How do we know which is true and which is a scam?

Comments are closed.

JM logo

Dr. Jarret Morrow MD on Instagram.