It is important to remember that products labelled as “natural” or herbal are not unquestionably safe. Any herbal remedy classified as a dietary supplement in the United States is regulated as a food product. This means it has not been subjected to the same requirements for safety or efficacy as medicines.

Garcinia cambogia (GC) has been implicated in causing liver damage, both when used in combination with other ingredients (for example, in the original formulation of the product Hydroxycut) and when used by itself. Two severe cases are documented. The first was a 52-year-old female who developed severe liver failure requiring a liver transplant after taking 1000mg of GC for 15 days, and the other was a 42-year-old female who developed abnormally high liver function tests and coagulopathy (an impaired ability of the blood to clot) after one week of taking GC. The second lady recovered without incident several days after GC was discontinued. Interestingly, the manufacturer of Hydroxycut temporarily withdrew the product, but it has since returned a reformulated version to the market that lacks GC.

Other reported adverse effects are generally mild when GC is taken at the recommended dosage and include stomach upset, dry mouth, headaches, dizziness, and diarrhea. Herbal remedies should not be taken by women who are pregnant or breastfeeding and anybody with a medical condition such as diabetes, dementia, or heart disease should consult their doctor before use.

On the positive side, unlike stimulants such as phentermine, GC does not act on the central nervous system, so does not cause sleeplessness, anxiety, affect the heart or blood pressure, and its efficiency does not decrease with time.