Garcinia cambogia, also known as the Malabar tamarind, is a small, sweet tropical tree fruit shaped like a pumpkin. In the late 1960s, scientists discovered an acid in the fruit somewhat similar to the citric acid found in fruits like oranges and lemons.

That acid—called hydroxycitric acid, or HCA—has ridden a rollercoaster ride of popularity over the last 20 years. It is alternately touted as a miracle weight loss supplement and derided as effective only in rats.

So where is the ride at now?