They tend to work via one or more of these mechanisms:

1. Reduce appetite, making you feel more full so that you eat fewer calories
2. Reduce absorption of nutrients like fat, making you take in fewer calories
3. Increase fat burning, making you burn more calories

How it works: Animal studies show that it can inhibit a fat-producing enzyme in the body and increase levels of serotonin, potentially helping to reduce cravings (1, 2 Trusted Source).

Effectiveness: One study with 130 people compared garcinia against a dummy pill. There was no difference in weight or body fat percentage between groups (3).

Side effects: There are no reports of serious side effects, but some reports of mild digestive problems.