Hydroxycitric Acid (HCA)
The active ingredient in Garcinia cambogia. HCA is an inhibitor of ATP-citrate lyase, an enzyme needed for the de novo synthesis of fatty acids. Garcinia cambogia extracts standardized for HCA are often added to fat loss supplements, although their efficacy is debatable.
See Paul’s review: “Citrimax / Hydroxycitric Acid (HCA): Does Citrimax Block Carbs?” for more information.