Does Garcinia cambogia work? Well, if you saw the Dr. Oz show, you heard him say “it may be the simple solution you've been looking for to bust your body fat good.” He's also said that garcinia cambogia was a “revolutionary fat buster” ―that requires no exercise, no diet, and, no effort. Those are very impressive words for sure. Ive been aware of this fruit and its alleged weight loss benefits for many years but in case you have not, I wanted to review Garcinia cambigia because there really is published research on this fruit. Let's now take a look at Garcinia and see if might be right of for you. See the Supplements and Liver Failure Review too.
What Is Garcinia Cambogia?
Garcinia is a pumpkin shaped fruit that grows in various regions of the world such as India, Asia and Africa. Its scientific name is Garcinia gummi-guta although some may know it by its other more familiar name, Hydroxy Citric Acid (or HCA). Hydroxy citric acid is an ingredient in garcinia cambogia, found usually in the skin (rind) and fruit that is that is often said to be the active ingredient in garcinia cambogia when it comes to weight loss.
How Does Garcinia Cambogia Work?
The most popular theory is that Garcinia cambogia is said to work by blocking the conversion of carbohydrates into fat. By doing this, fat storage is reduced. Others speculate that Garcinia can help weight loss is by decreasing appetite. This effect may be related to reports that Garcinia can increase levels of serotonin, a chemical that does several things, including reducing appitite. During the Dr. Oz segment, this was brought up as a potential benefit to “emotional eaters.” It could be that Garcinia works in all these ways and in other ways also.
Garcinia cambogia has been an ingredient in several products I've already reviewed including:
So do read those reviews for additional information
Garcinia cambogia is also available as a standalone supplement. In other words, you can buy a bottle of just Garcina cambogia. Supplements of Garcinia may be labeled as Garcinia cambogia, Garcinia extract, HCA extract, Garcinia cambogia extract or simply “GCE.”
Garcinia Cambogia Research
I wanted to see what weight loss research there was on garcinia. So I searched the National Library of Medicine for these words:
- Garcinia cambogia weight loss
- HCA weight loss
- hydroxy citric acid weight loss
I found several studies. Studies exist in both mice and humans. I'm going to limit this review to mostly the human research to make the results more meaningful. As you do your own research, keep in mind that some supplements may list garcinia by another name – tamarind.
In 2012 a study, titled Oral hydroxycitrate supplementation enhances glycogen synthesis in exercised human skeletal muscle was published in the British Journal of Nutrition. In this study, 38 young men were given 500 mg of HCA or a placebo along with a high carbohydrate meal after exercise (60 minutes of cycling at 75% of maximum aerobic ability). Biopsies of the thigh muscle were taken immediately after exercise and 3 hours later. Researchers noted that men who received 500 mg of HCA had significantly lower levels of insulin. HCA also increased the formation of glycogen, the storage form of carbohydrates in the muscles.
Note. This study plus the 2007 rat study below, appear to lend believability to claims that Garcinia cambogia helps insulin resistance, and hence type II diabetes. This may be one of the reasons why Garcinia cambogia might be found in diabetes supplements such as Diab-X which I reviewed previously.
In 2011, a study titled Does Glycine max leaves or Garcinia Cambogia promote weight-loss or lower plasma cholesterol in overweight individuals: a randomized control trial was published in Nutrition Journal. The study lasted 10 weeks and involved 68 overweight men and women. The people were randomly broken into groups that received the following:
- Garcinia cambogia extract (2 grams per day)
- Glycine max leaf extract (soybean) 2 grams per day
After the study, there were no significant differences between the groups in body weight or cholesterol levels.
In 2007 a study titled Super CitriMax (HCA-SX) attenuates increases in oxidative stress, inflammation, insulin resistance, and body weight in developing obese Zucker rats was published in the journal, Molecular and Cellular Biochemistry. As can be seen in the title, this was a rat study. Rats with type II diabetes that were given the HCA extract had reduced levels of C reactive protein (a sign of inflammation), glucose , insulin and triglycerides. The rats also ate less food and had reduced body weight compared to rats getting the placebo.
In 2007 a study titled Reduction of adipose tissue and body weight: effect of water soluble calcium hydroxycitrate in Garcinia atroviridis on the short term treatment of obese women in Thailand was published in journal, Asia Pacific Journal of Clinical Nutrition. This study involved 50 obese women (18-75 years of age) who were randomly split into 2 groups:
- Garcinia group
- Placebo group
Those getting Garcinia received 1.15 grams before meals, three times per day (3.45 grams total per day). In this study, the women used Garcinia atroviridis which is a related species to Garcinia cambogia.
All women were put on a 1000 calorie per day diet and tracked for 2 months. Body fat was determined using skin fold analysis and bioelectric impedance analysis.
At the end of the study, women getting Garcinia atroviridis lost significantly more weight (6.1 lbs) than women who received the placebo (3 lbs).
In 2004, a study titled An overview of the safety and efficacy of a novel, natural(-)-hydroxycitric acid extract (HCA-SX) for weight management was published in the Journal of Medicine. This study involved both rats and humans. Let's just look at the human part of the study. This was an 8 week study that involved 60 people. The people were given 2000 calories per day, walked 30 minutes a day, 5 days per week and were randomly given either a placebo or 4666.7 mg (about 4.7 grams ) of a supplement called Super CitriMax. At the end of the study, these results were observed in those who took Super CitriMax:
- 5.4% reduction in body weight
- 5.2% reduction in body mass index (BMI)
- Significantly decreased food intake
- Significantly decreased total cholesterol
- Significantly decreased LDL (bad cholesterol)
- Significantly increased HDL (good cholesterol)
- Significantly decreased triglycerides
- Significantly decreased leptin levels
- Significantly increased serotonin levels
Note. Leptin is a hormone made inside fat cells. Leptin plays a role in hunger.
In 2003 a study titled Effects of Garcinia cambogia (Hydroxycitric Acid) on Visceral Fat Accumulation: A Double-Blind, Randomized, Placebo-Controlled Trial was published in the journal, Clinical Therapeutic Research. In this study, 39 overweight people (20-65 years of age) were randomly given either a placebo or Garcinia cambogia for 12 weeks, along with a reduced calorie diet (The men ate 2250 calories per day. Women consumed 1800 calories per day).
Those in the Garcinia group received a supplement that contained 1667 mg of Garcinia cambogia extract. This supplement contained 1000 mg of hydroxycitric acid (HCA is thought to be the active ingredient in Garcinia cambogia).
Those taking the Garcinia extract lost significantly more abdominal fat and had more total fat loss, compared to those who received the placebo.
In 2002 a study titled The effect of (-)-hydroxycitrate on energy intake and satiety in overweight humans was published in the International Journal of Obesity and Related Metabolic Disorders. This study lasted 2 weeks and involved 24 overweight people (12 men and 12 women). People were randomly split into groups that either received 900 mg of HCA or a placebo.
The supplement containing the HCA was called Super CitraMax. After the study, researchers noted that those who took HCA consumed less calories compared those who received the placebo. This was deemed primarily to decreased snacking. There was a “tendency to a decrease in body weight” between the groups of about 1 pound in those taking HCA, but this was not a significant difference.
In 2001, a study titled The effects of 2-week ingestion of (–)-hydroxycitrate and (–)-hydroxycitrate combined with medium-chain triglycerides on satiety, fat oxidation, energy expenditure and body weight was published in the International Journal of Obesity and Related Metabolic Disorders.
This investigation consisted of 11 overweight men and lasted 2 weeks. In the study, men consumed 3 meals and 4 same-calorie snacks a day. The men were randomly given
- A placebo
- 500 mg HCA
- 500 mg HCA plus 3 grams of medium chain triglycerides (MCT)
At the end of the study, everybody lost weight, but there was no significant differences between those getting the placebo and those getting HCA or HCA + medium chain triglycerides.
In 2000, a study titled, Effects of (-)-hydroxycitric acid on appetitive variables published the journal, Physiology and Behavior. This study involved 89 overweight women who were put on a low calorie diet and randomly given either a placebo or 2.4 grams of Garcinia cambogia per day (this equaled 1.2 grams of HCA). The length of the study was 12 weeks (3 months). At the end of the study, those taking HCA supplements lost more weight (8 lbs) than those taking the placebo (5 lbs).
In 1999, a study titled (-)-Hydroxycitric acid does not affect energy expenditure and substrate oxidation in adult males in a post-absorptive state was published in International Journal of Obesity and Related Metabolic Disorders. This study involved 10 overweight and obese men. The men randomly were given either a placebo or HCA (3 grams per day). The study lasted 3 days. The researchers wanted to see if the HCA in Garcinia cambogia increased fat burning and metabolic rate at rest and during moderate exercise. In both cases, HCA failed to cause any significant changes.
In 1998, a study titled Garcinia cambogia (hydroxycitric acid) as a potential antiobesity agent: a randomized controlled trial was published in the Journal of the American Medical Association. This study lasted 12 weeks and involved 135 obese men and women who were randomly given either hydroxycitric acid (1500 mg per day) or a placebo, along with a high fiber, low calorie diet (84 people completed the study). At the end of the study, both groups lost weight, (the placebo group lost a little more weight) however there were no significant differences in the weight loss between groups. So, according to this study Garcinia cambogia did not work better than a placebo.
In a review of garcinia cambogia (and other supplements) that mentions this study, published in 2011, in the Journal of Obesity, the author notes that a problem with this study is that the placebo group lost a greater percent of body fat (2.16%) than those who received HCA (1.44%).
Summary Of Garcinia Research
- 2011 study: Human study. Garcinia didn't work. 2 grams per day used.
- 2007 study: Rat study. Garcinia worked.
- 2007 study: Human study. Garcinia worked. 3.45 grams per day used.
- 2004 study: Human /rat study. Garcinia worked. 4.7 grams per day used.
- 2003 study. Human study. Garcinia worked. 1667 mg per day/1000 mg HCA used.
- 2002 study: Human study. Garcinia didn't work. 900 mg HCA per day used.
- 2001 study: Human study. Garcinia didn't work. 500 mg HCA used.
- 2000 study: Human study. Garcinia worked. 2.4 g / 1.2 grams HCA used.
- 1999 study: Human study. Garcinia didn't work. 3 grams of HCA per day used.
- 1998 Study: Human study. Garcina didn't work. 1500 mg of HCA per day used.
From this research, it appears 5 investigations noted that Garcinia cambogia helped weight loss in humans. Just as many studies showed it didn't work. Those studies showing a positive effect on weight loss also incorporated a reduced calorie diet. In other words, you have to eat less. You can't just pop a pill.
Here is a Garcina cambogia supplement on Amazon that gets high marks from people.
Garcinia Cambogia And Cortisol
During the Dr. Oz show about garcinia, Dr. Julie Chen, who was featured in the segment, mentioned that garcinia helps to manage the stress hormone cortisol” which might help decrease belly fat. I searched the national library of medicine for
- Garcnia cambogia cortisol
- HCA Cortisol
- hydroxy citric acid cortisol
I was not able to find any human studies showing garcinia reduced cortisol. In fact, in this 2008 study of a supplement containing garcinia cambogia and L carnitine, no change in cortisol was seen. As such, Im not sure where Dr. Chen got that information. If anyone knows, please let me know.
Garcinia Cambogia Side Effects
As a rule follow these instructions
- Stop taking garcina at least 2 weeks before having surgery
- Don't take if you are pregnant or breast feeding
- Speak to your doctor/pharmacist /dietitian if you take ANY prescription medications
- To reduce side effects, start with less than the recommended amount for the first week.
Most studies of Garcinia cambogia don't last long. That makes it difficult to determine side effects. For example, the longest study I saw was 3 months. The most common side effects reported include:
- GI problems
- Feelings of being nauseous
These are common side effects for many dietary supplement studies.
In a review of the safety, the author noted that most of the human studies have involved small groups of people that were carried out over short periods of time. Thus, long term side effects of garcinia cambogia in appears to be unknown.
Checking Amazon, those who rated it as 1 star, said that garcinia caused rapid heart rate, gas/bloating, lack of energy and headaches. Those people also said Garcina Cambogia did not help them lose weight. This goes back to the research which says it's basically a 50/50 shot of it working.
Some lab rat research suggests the HCA in Garcinia Cambogia might be toxic to the testis. Not all researchers agree with this assessment, such as this review of the toxicity of garcinia Cambogia. To be safe, men should discuss this with their urologist for more up to date information.
People who take antidepressant medications should speak to their doctor before taking garcinia. There is some evidence that when combined with antidepressant medications (such as SSRIs), garcinia may make serotonin levels go to high. This is called serotonin syndrome can result in dangerously high blood pressure.
And then there is the liver failure controversy. Let's take a closer look at that next.
Garcinia Cambogia And Liver Failure
For several years there have been reports of liver toxicity and liver failure resulting from weight loss supplements containing Garcinia cambogia. Most of these reports stem from the use of a Garcinia-containing supplement called Hydroxycut.
Since I first write this review, Ive changed my mind. While I first attributed this to something in Hydroxycut or the results of various ingredients, I now believe there is good evidence to prove garcinia cambogia causes liver failure in some people.
The thing whcih changed my mind was a report of a 34 year old male who needed a liver transplant. He admitted to taking two 80mg capsules of “Swanson Premium Brand Garcinia Cambogia 5:1 Extract.” This supplement ONLY contained garcinia cambogia. Based on this, I recommend EVERYONE avoid garcinia cambogia supplements
For those doing their own research, here are some of case reports and review articles I found:
- Hepatotoxicity Associated with Use of the Weight Loss Supplement Garcinia cambogia: A Case Report and Review of the Literature.
- Hydroxycut hepatotoxicity
- Hydroxycut(®) (herbal weight loss supplement) induced hepatotoxicity: a case report and review of literature
- Hydroxycut hepatotoxicity: A case series and review of liver toxicity from herbal weight loss supplements
- Fatal liver failure following food supplements during chronic treatment with montelukast.
- Two patients with acute liver injury associated with use of the herbal weight-loss supplement hydroxycut
Many other supplements are linked to liver failure too.
See the Supplements & Liver Failure review for more information
Garcinia Cambogia And Rhabdomyolysis
Rhabdomyolysis is a serious medical condition that basically results in your muscles dying. Kidney failure is one of the most serious side effects of this disorder, which is abbreviated as “Rhabdo.”
As I mentioned in my book about rhabdo, some supplements can cause this condition too.
Back in 2004 there was a case report of a 54 year old woman who got rhabdo after taking a supplement that contained garcinia cambogia. But, that supplement contained many other ingredients- including ephedra. Stimulants have been known to cause rhabdomyolsys.
Because of this, my hunch is that it might not be garcinia cambogia that caused rhabdomyolysis, but rather the ephedra in the supplement. That said I can't be sure either way. Other than this case report, I'm not aware of any cases of garcinia cambogia causing rhabdo.
Regardless, if you think you have rhabdo, my best advice is to go to your doctor – or hospital. A simple blood test can tell if you have it or not. Rhabdo is VERY serious condition that can result in kidney failure. Do not take this lightly.
Here is my review of rhabdo and exercise is you want to learn more. Read the comments there too.
Who Should Not Take Garcinia Cambogia
If you saw the Dr. Oz segment on Garcinia, you may have noticed he mentioned that:
- Women who are pregnant/breastfeeding
- Taking prescription medications
- Taking diabetes medications
should talk to their doctor before experimenting with Garcinia cambogia. To this, I'd also add, kids, under the age of 18. As I pointed out on my FAQ page, there isn't a lot of weight loss supplement research that involves kids. Kids are not miniature adults.
How Much Works?
On the Dr. Oz segment on Garcinia cambogia, you may have heard that they recommended 1500-3000 mg (1.5 grams to 3 grams) per day, that ―and this is important ―contained at least 50% of hydroxycitric acid (HCA).
Notice from my review of the research that as much as 3.45 grams of Garcinia has been used with positive results. I mention this for those in which 3 grams did not work.
- I see no proof that more than 3.45 grams of Garcinia cambogia is needed.
- Garcinia cambogia should be taken on an empty stomach, about 30 minutes before meals.
- Many Garcinia cambogia supplements also contain calcium or potassium. This is to increase the absorption.
It's likely that they will see Garcinia cambogia supplements that also contain other ingredients, like, raspberry ketones, green coffee extract, hoodia ―or whatever else is the “hot, sexy” supplement of the month (see those reviews for more info).
Dr. Oz And Garcinia Cambogia
It's likely that a many people first heard of Garcinia cambogia extract when it was featured on the Dr. Oz show. While I do agree with Dr. Julie Chen MD, who was featured on the show, that Garcinia is one of the least expensive weight loss supplements, I was disappointed that neither of these doctors mentioned the reports of liver toxicity that may be related to garcinia.
That said, during the segment, Dr. Oz said something that I feel needs repeating. Specifically he said :
“You should never see my picture next to it (Garcinia cambogia). “If you see my picture next to it, that means they're stealing from you.”
Dr. Oz knows that as soon as he mentions a supplement, that people will try to use his picture and fame to promote their product. Dr. Oz does not sell any supplements and he does not endorse any particular brand of Garcinia supplement. So, I think a good rule of thumb when evaluating supplements (any supplement) is, if you see a picture of Dr. Oz on a supplement website, don't buy that product in the hopes that Dr. Oz endorsed it. He didn't.
Does Garcinia Cambogia Work?
Looking at the research, I feel its a crap shoot if it works or not. I see just as many studies showing it works as doesn't work. But, whether it works or not, I won't recommend garcinia cambogia. The possibility of liver failure scares me too much. If your supplements contain garcinia cambogia, throw them away. I don't believe they are safe.