Garcinia cambogia was first mentioned by Dr. Mehmet Oz in 2012 as a weight loss “holy grail.” With his television show's recent focus on weight loss methods, the fruit is back on the radar, but is Garcinia cambogia really the weight loss “holy grail” that Oz claims it to be?

Garcinia cambogia is a fruit also known as Gambooge. The fruit is native to parts of Asia and Africa and used often in cooking. In traditional medicine, Garcinia cambogia has been used as a stool softener and to treat constipation. The fruit is gaining plenty of fans after Oz featured the product on his television show. While he touted it as another weight loss miracle, the evidence for Garcinia cambogia’s effectiveness is questionable at best.

Garcinia cambogia extract is called hydroxycitric acid and is found in Hydroxycut. There was concern about the weight loss supplement following several cases of hepatotoxicity (liver damage or failure), according to a letter published in the World Journal of Gastroenterology.

In a larger meta-analysis of Garcinia cambogia studies, published in the Journal of Obesity, nine trials and studies were examined to determine what effects the fruit had on weight loss. In the studies, 706 participants altogether were given Garcinia cambogia and the researchers found that, across the studies, the extract did have a small, but statistically significant, effect on weight loss but ultimately does not have clinical relevance. There were some side effects associated with hyrdoxycitric acid, including “headache, skin rash, common cold, and gastrointestinal (GI) symptoms.” In one study, GI side effects were twice as likely in the hydroxycitric acid group compared to the placebo group.

Garcinia cambogia and HCA has been studied since the 1990s, and one of the first studies on the fruit’s effect on weight loss was published in the Journal of the American Medical Association. The study was a 12-week randomized, double-blind, placebo-controlled trial that involved 142 participants. Half were given HCA while the other group was given a placebo. While both groups lost weight, there was no statistical difference between either group, meaning HCA was just as good as placebo when it came to aiding in weight loss.

While a 2005 study involving overweight rats caused concern due to testis toxicity, more recent studies, including a 2008 study involving humans and blood levels of sex hormones, have quelled those fears. As for overall health concerns involving the use of HCA or Garcinia cambogia, in terms of safety and effectiveness, a 2012 study, published in Critical Reviews of Food Science and Nutrition, noted that the use of the supplement based on recommended dosages seems to be safe but there have yet to be any long-term studies focusing on safety. The researchers write, “There is still little evidence to support the potential effectiveness and long-term benefits of G. cambogia extracts. With regard to toxicity and safety, it is important to note that except in rare cases, studies conducted in experimental animals have not reported increased mortality or significant toxicity.”

Ultimately, it seems Garcinia cambogia is not everything Oz makes it out to be. While the results are inconclusive, that’s evidence enough that the fruit, or HCA, is not the “holy grail” where individuals can take the supplement and watch the pounds fly off. As always, consult your real doctor before taking any dietary supplements.