Review: Garcinia Cambogia vs. Green Coffee

Among the most sought-after nutritional diet supplements in the country today are those formulated with either green coffee bean extract (GCBE) or Garcinia cambogia extract (GCE). Both formulations are being marketed more for their respective weight loss promise than any other health benefits for which they also provide. People ask me which is the better choice in the weight management department? Let’s takes a brief look at each.

Garcinia Cambogia

A small fruit native to Indonesia, India and other South and Southeast Asian countries, the Garcinia cambogia looks to me like a pumpkin the size of an orange and is valued as a souring ingredient in several local dishes in these countries. The chemical extract called Hydroxycitric acid (HCA) is most abundant in the fruit rind and its concentrate is formulated in pills and capsules as weight loss diet supplements. Is it effective in weight management?

I remember Dr. Oz in his TV show sometime in 2012 bringing this relative unknown fruit into the limelight with a study that showed you could lose 3-4 lbs every month even without altering your eating lifestyle. The HCA in the extract has been shown in several studies to have anti-obesity properties by primarily suppressing appetite and inhibiting fat storage. Its appetite suppressing efficacy is suggested to be triggered by increasing serotonin levels which create satiation levels with lower food intake while managing mood levels that significantly reduce the hunger pangs among frequent snackers and emotional binge eaters.

Green Coffee Bean

Raw freshly harvested coffee beans are green. They contain a very potent chemical compound called Chlorogenic Acid (CGA) which is abundant when fresh but effectively disappears when roasted to become the dark brown coffee beans we grind for our morning cup of brewed coffee. What makes green coffee beans special is its chlorogenic acid content which in 45% to 50% concentrate form in diet supplements has excellent bioavailability that makes its clinically proven antioxidative, anti-obesity and anti-hypertensive properties easily effective. But is it any good in reducing weight?

TV health celebrity Dr. Mehmet Oz featured this green coffee extract in his September 2012 episode as a weight loss solution that enabled dieters to shed excess pounds and trim the fat without altering their consumptive and sedentary lifestyles. I knew about green coffee but I never realized until then about its weight loss properties. The hype was certainly not without basis, After researching online, I came across several lab and clinical studies that pointed to the chlorogenic acid concentrate to have remarkable health-restoring and weight reducing properties. Heather Hausenblas, Ph.D., an associate professor from the University of Florida has endorsed GCBE in either capsule or chewable tablet for its pharmacological ability to increase fat metabolism that lead to weight loss.

Weight loss mechanism compared

Garcinia Cambogia: How It Works

The hydroxycitric acid (HCA) in the Garcinia plant is typically used as an appetite suppressant while purportedly promoting the biosynthesis of serotonin, a chemical neurotransmitter that defines a “feel good” or satiated feeling. Raising serotonin levels increases you level of satiation thereby reducing hunger pangs that would otherwise cause you to consume more and thus, gain weight. The same pharmacological action manages mood swings that often drive people to frequent snacking and binge eating that are the most common causes of gaining excess weight.

Another pharmacological potency behind HCA is its ability to suppress the enzyme adenosine triphosphate-citrate-lyase (ATP citrate lyase), known to promote the conversion of unused fats into lipids that get stored in the body’s tissues, resulting in fat metabolites getting flushed out of the body in the bowel or urine.

Green Coffee

The ability of green coffee bean extract to reduce weight can be traced to its ability to increase fat metabolism and retarding the release of sugars into the blood and the production of insulin in the liver. Simple sugar or glucose enters the blood after consuming a meal or beverage and triggers the liver to release insulin which allows excess glucose to be stored as fat. By retarding glucose absorption into the bloodstream while enhancing the breakdown of fatty acids in the liver, the chlorogenic acid (CGA) in GCBE inhibits fat absorption into the tissues and burns them off as usable energy, allowing you to lose weight even with excess fat intake.

Chlorogenic acid inhibits fat accumulation by resisting lipolytic enzyme activity through the action of ferulic or feruloylquinic acid, a constituent chemical in the CGA which is a powerful inhibitor of the enzyme glucose-6-phosphatase translocase (G6PT). G6PT happens to be critical in metabolizing sugar from ingested foods while regulating sugar content in the bloodstream. As people exercise or take in low calorie food, their livers automatically produce the glucose in the liver. But CGA inhibits the action of G6PT so that hepatic sugar regeneration stops. Hence, you lose weight or regain lost weight which is often the issue among weight watchers.

The same pharmacological action accounts for GCBE’s ability to reduce the risk of becoming diabetic in an obese condition. The CGA retards the release of sugars in the blood stream which helps in reduce inulin rejection. And because CGA’s Ferulic Acid constituent is an anti-oxidant to begin with, it promotes the release of nitric oxide to improve relax arterial walls for improved blood circulation. Hence, CGA is also anti-hypertensive.

Comparing Clinical Studies

After going through several studies on the two extracts, I noted a few that clearly showed some differences in their abilities to reduce weight, but these are mostly due to testing differences. I am not aware of an single study that compares the two under the same set of controllable factors.

Garcinia Cambogia

In his 2012 TV show, Dr. Oz featured the study of wellness specialist Dr. Julie Chen whose research indicated an average loss of 17 lbs over a three month period which is roughly 10.5% of body weight without altering the eating habits of her subject. This translates to around 5.6 lbs each month on average.

This 12-week clinical trial (source) conducted in 2000 involving 89 mildly overweight women half of whom were treated with 400mg of Garcinia Cambogia 60 minutes prior to each meal resulted in significant weight loss averaging 3.7 kg at the end of the 3-month of the period. That’s equivalent to 8.1 lbs and is just about 4 lbs shy from the study featured by Dr. Oz indicating as much as 3 lbs loss each month.

Another clinical study conducted in India in 2004 (source) involving 60 mildly overweight patients treated with an unspecified amount of the extract resulted in 5% -6% reduction in weight over the study’s 8-week intervention period. The result was attributed to fewer food intake indicating the efficacy of GCE as an appetite suppressant. If you are overweight at 180 lbs, that means you could lose 9 lbs in just two months.

Green Coffee

On the other hand, the clinical studies on the weight loss impact of green coffee have been fewer. In his May 2012 TV show, Dr. Oz invited 100 women from his audience to take part in a study to confirm the weight loss benefits of green coffee as featured in the research of naturopathic doctor Lindsey Duncan. Over a three month period, half of the volunteers treated with the green coffee bean extract showed a remarkable weight loss averaging 2 lbs each week, effectively confirming Dr. Lindsay Duncan’s results.

In a 2012 clinical study on 16 moderately overweight subjects (source), there was an 8kg (17.6 lbs) weight reduction over a 5.5 month intervention period that enabled 6 of the 16 participants to go from mildly obese to normal. This translated to a more modest but equally effective 3.2 lbs weight loss each month.

Comparing the side effects

As far as my research went, both extracts have been shown to be clinically safe at the dosages indicated in the labels of diet supplements containing either. Having said that, I share the same caution of most health pundits that children, pregnant women and lactating mothers stay clear from either supplements since no study exists that can confidently affirm their safety for these groups. It is always best to consult with your physician before taking any over-the-counter drug or supplement, especially if you are taking some other drug to treat an ailment. There are also no known studies about the drug interaction of the two extracts.

Garcinia Cambogia side effects

Just about all the lab and clinical studies I know confirm the safety of Garcinia cambogia extracts over the short term treatment period and the dosages indicated at dosages below 1.500 mg prior to each meal. To date, there is no published evidence to indicate that the HCA in the fruit has any significant toxicity to warrant withdrawing from the extract.

Green Coffee side effects

Green coffee contains small amount of caffeine and is significantly lower than what you get from roasted dark brown coffee. A cup of brewed coffee has anywhere from 100mg to 150mg of caffeine while GCBE supplements are generally decaffeinated to contain a fraction at 8mg to 23mg of caffeine. This yawning disparity in caffeine content accounts for the absence of any adverse side effects we’ve come to associate with coffee intake such as palpitation, heightened nervousness, rapid breathing and sleep disorders such as insomnia.

A Few Reviews on Either Extracts

Since Dr. Oz featured the “miracle” weight loss solutions in natural concentrated extracts from green coffee beans and the Garcinia cambogia fruit, drug companies lost no time marketing diet supplements formulated with either extracts and with them came a slew of online reviews on the extracts. Here’s a sampling:

(1) From Tom Davidson on both Garcinia cambogia and Green Coffee Bean extracts (–pure-garcinia-cambogia-or-green-coffee-bean-max-wdf402a7c00)

GCBE is a fat-buster that suppresses appetite and blocks new fat cells being formed from excel intake of carbs and sugar. This is what comprises an effective weight loss supplement that can also work with other fat-removing diet supplements formulated with Moringa Ollefera known to boost energy levels. In the same vein, Green Coffee Bean extract has natural fat-burning properties thanks to its Chlorogenic Acid extract which presents a “significant breakthrough in the science of natural weight loss.”

(2) From Chelsea Patrick on Garcinia Cambogia (

Medical studies have “discovered” that the HCA extract from the fruit rind, ingested as a diet supplement pill in your daily diet regimen, promises to enable weight loss at a faster pace. In fact, a number of studies have shown that you can lose weight three times faster with HCA than with regular dieting methods as most weight watchers average 4 lbs lost every month. The supplement promotes weight loss by obstructing fat storage and suppressing appetite. It raises serotonin levels and can manage moods of emotional eaters.

(3) From Joe Cannon on Green Coffee Beans (

Three studies showed that overweight individuals taking green coffee bean extract have “significantly greater weight loss” than those taking placebos. Though the effects were moderate, there is no doubt about its weight loss promise, but until better studies are done, there is really not much certainly about its efficacy.


My personal experience with green coffee extract, losing about 12 lbs over a three month period, might prompt me to endorse it over the Garcinia extract. But the studies behind the Garcinia fruit can’t be ignored and the reviews of health pundits who attest to the efficacy of the Garcinia Cambogia extract along with the experience of my colleagues in the office provide enough confidence that when taken regularly, the extract can do wonders for your dieting regimen.

Both extracts have been hailed to reduce weight without altering you eating lifestyle. I personally would recommend doing some moderate workouts and reducing your fat and calorie intakes within the limits that won’t make you salivate on the foods you love. In my case, some aerobics every other day and reducing my after-meal deserts have sped up the weight losses I see when taking GCBE. All health experts agree that weight loss diet supplements work best when there’s a corresponding shift to a healthier lifestyle. Between green coffee and the gambooge, I wouldn’t be losing sleep choosing either if I were to start all over again. In fact, with some diet supplements out there containing both extracts, it may be a better choice to just have both in your diet regimen.