Have any supplements been studied for obesity?

Many dietary supplements and dietary ingredients have been studied for weight loss. In a recent meta-analysis of 67 randomized trials, the dietary ingredients chitosan, glucomannan, and conjugated linoleic acid were shown to help reduce weight by 1–1.9 kilograms. Other ingredients commonly studied for weight loss include green-tea-extract, green-coffee-extract, bitter orange, and Garcinia cambogia. Evidence about their effects is limited.^[1]