Garcinia cambogia is a popular weight loss supplement.
It is derived from a fruit of the same name, also called Garcinia gummi-gutta or Malabar tamarind.
The peel of the fruit contains high amounts of hydroxycitric acid (HCA), which is the active ingredient believed to be responsible for most of the weight loss benefits ().
This article is a detailed review of garcinia cambogia and whether it is something you should take in order to lose weight.
Garcinia gummi-gutta is a small, pumpkin-shaped, yellow or greenish fruit.
The fruit is so sour that it is generally not eaten fresh, but rather used for its sour flavor in cooking ().
Garcinia cambogia supplements are made from extracts of the fruit's peel.
The peel of the fruit contains high amounts of hydroxycitric acid (HCA), an active substance that has been shown to have some weight loss properties (, , ).
The supplements generally contain 20–60% HCA. Nevertheless, studies show that those with 50–60% HCA may provide the most benefit ().
Bottom Line: Garcinia cambogia supplements are made from extracts of the peel of the Garcinia gummi-gutta fruit. They contain high amounts of hydroxycitric acid (HCA), which has been linked with weight loss benefits.
Many high-quality human studies have tested the weight loss effects of garcinia cambogia.
What's more, most of them show that the supplement can cause a small amount of weight loss (, ).
This graph summarizes the weight loss results from nine studies on garcinia cambogia (, , , , , , , ):
The blue bars show the results from the supplement groups, while the orange bars show the results of placebo groups.
On average, garcinia cambogia has been shown to cause weight loss of about 2 pounds (0.88 kg) more than a placebo, over a period of 2–12 weeks (, ).
That said, several studies have not found any weight loss advantage (, , ).
For example, the largest individual study, which tested 135 participants over 12 weeks, did not find any difference in weight loss between the group that took garcinia cambogia and the group that took the placebo ().
As you can see, the evidence is mixed. Garcinia cambogia supplements can produce modest weight loss in some people, but their effectiveness cannot be guaranteed.
Bottom Line: Some studies have found that garcinia cambogia causes modest weight loss, while other studies report no noticeable effects.
There are two main ways garcinia cambogia is thought to help with weight loss.
1. It May Reduce Your Appetite
Studies in rats have shown that those given garcinia cambogia supplements tend to eat less (, ).
Similarly, some human studies have shown that garcinia cambogia is able to suppress appetite and make you feel full (, , , , ).
How it reduces appetite isn't fully known, but rat studies have suggested that the active ingredient in garcinia cambogia can increase serotonin in the brain (, ).
Theoretically speaking, since serotonin is a known appetite suppressant, higher blood levels of serotonin could reduce your appetite ().
However, these results need to be taken with a grain of salt. Other studies have found no difference in appetite between groups taking this supplement and those taking a placebo (, , , ).
It may be that these effects depend on the individual.
Bottom Line: Some studies suggest that garcinia cambogia can suppress appetite by inhibiting serotonin uptake in the brain, while other studies have found no effects on appetite or hunger.
2. It May Block Fat Production and Reduce Belly Fat
The most important activity of garcinia cambogia is probably its effects on blood fats and the production of new fatty acids.
Studies in humans and animals have shown it may lower high levels of fat in the blood and reduce oxidative stress in the body (, , , , ).
One study also suggests it may be especially effective at reducing the accumulation of belly fat in overweight people ().
Another study gave moderately obese individuals 2,800 mg of garcinia cambogia daily for eight weeks ().
By the end of the study, the group had drastically reduced several risk factors for disease:
- Total cholesterol levels: 6.3% lower
- LDL (the "bad") cholesterol levels: 12.3% lower
- HDL (the "good") cholesterol levels: 10.7% higher
- Blood triglycerides: 8.6% lower
- Fat metabolites: 125–258% more excreted in the urine
The main reason for these effects is thought to be that garcinia cambogia inhibits an enzyme called citrate lyase, which plays an important role in the production of fat (, , , , ).
By inhibiting citrate lyase, garcinia cambogia is thought to slow down or block fat production in the body. This may reduce blood fats and lower the risk of weight gain, two major disease risk factors ().
Bottom Line: Garcinia cambogia blocks the production of new fats in the body, and has been shown to lower cholesterol levels and blood triglycerides in overweight people.
Animal and test-tube studies suggest that garcinia cambogia may also have some anti-diabetic effects, including (, , ):
- Decreasing insulin levels
- Decreasing leptin levels
- Reducing inflammation
- Improving blood sugar control
- Increasing insulin sensitivity
Garcinia cambogia may also have benefits for the digestive system. Animal studies have suggested it helps protect against stomach ulcers and reduce damage to the inner lining of the digestive tract (, ).
However, these effects need to be studied further before firm conclusions can be drawn.
Bottom Line: Garcinia cambogia may have some anti-diabetic effects and may also help protect against stomach ulcers and damage to the digestive tract.
Most studies have concluded that garcinia cambogia is safe for healthy people in the recommended dosages, or up to 2,800 mg of HCA per day (, , , ).
That said, supplements are not regulated by the US Food and Drug Administration (FDA).
That means there's no guarantee that the actual content of HCA in your supplements will match the HCA content on the label.
Therefore, make sure to buy from a reputable manufacturer.
People have also reported some side effects of using garcinia cambogia. The most common ones are (, ):
- Digestive symptoms
- Skin rashes
However, some studies have indicated more serious side effects.
Animal studies have shown that a very high intake of garcinia cambogia can cause testicular atrophy — shrinking of the testicles. Studies in rats have shown it may also affect sperm production (, , ).
Additionally, there is one report of a woman who developed serotonin toxicity as a result of taking garcinia cambogia with her anti-depressant medications ().
If you have a medical condition or are taking any medications, consult your doctor before you start taking the supplement.
Bottom Line: Some people experience digestive symptoms, headaches and skin rashes when taking garcinia cambogia. Animal studies suggest that a very high intake may cause toxicity.
Many health food stores and pharmacies offer several varieties of garcinia cambogia.
Choose one from a reputable manufacturer that contains 50–60% hydroxycitric acid (HCA).
Recommended dosages can vary between brands. Generally, it is recommended to take 500 mg, three times per day, 30–60 minutes before meals.
It is always best to follow the dosage instructions on the label.
Studies have only tested these supplements for up to 12 weeks at a time. Therefore, it may be a good idea to take a few weeks off every three months or so.
Bottom Line: Look for a supplement that contains 50–60% HCA and is made by a reputable manufacturer. Follow the dosage instructions on the label.
Existing studies don't agree on the effectiveness of garcinia cambogia for weight loss.
Some studies show it may cause slightly more weight loss than not taking any supplement. This effect is not confirmed, but it is promising.
The positive effects of garcinia cambogia on blood fats may be where this supplement really shines.