The widely-advertised supplement Garcinia cambogia has not been shown to help people lose weight and keep it off, and may not even be safe. The main ingredient is extracted from the rusty-red fruit of a small tree that grows in Asia. Its rind contains hydroxycitric acid (HCA) that is a laxative; this is advertised as the active ingredient for weight loss. Early reports showed that HCA may make you feel full earlier when you eat. It has been shown to increase stored sugar (glycogen) in the liver, which can lower the bad LDL cholesterol. A recent study shows that HCA pills caused fat mice to lose fat, and be less likely to become diabetic, but it also caused significant scarring in their livers (World J Gastroenterol, 2013;19:4689-4701). Several people have developed liver failure and even death after taking HCA (Ann Intern Med, 2005;142:477-478 and 2009;151:673-674). Long-term use of laxatives can cause dehydration and malabsorption problems.
A review of the medical literature on garcinia’s effect on weight loss found 23 trials of which 11 had controls and were scientifically acceptable (Journal of Obesity, 2011;Article ID 509038). Using the results of the acceptable articles, the authors calculated a little less than a two-pound difference between those taking garcinia and those taking a placebo. The articles showed that those who took garcinia had twice as many side effects as those who took placebos. One study showed no difference between HCA and placebo (Nutr J. 2011;10:94). A study of 24 overweight people showed that two weeks of taking garcinia decreased food intake slightly, but did not cause significant weight loss (Int J Obes Relat Metab Disord, 2002;26:870-872). Another study showed that Garcinia cambogia reduced belly fat in humans (Current Therapeutic Research, September–October 2003;64(8):551–567). A study of 60 obese individuals in India showed dramatic benefits after eight weeks, including a five percent weight loss, decreased food intake, and lowering of cholesterol, bad LDL cholesterol and triglycerides (Diabetes Obes Metab, 2004;6:171-180). I am bothered that this study also reported an increase in the good HDL cholesterol with decreased food intake and weight loss. With food restriction and weight loss, the good HDL cholesterol would be expected to go down.
People who want to lose weight and keep it off need to take in fewer calories than they burn. As of today, nobody has shown that any pill will cause people to lose weight and keep it off unless they also eat less and exercise more. People who burn more calories than they take in will lose weight without using any pills. If you want to lose weight, I recommend that you try intermittent fasting.