It has been shown in actual (double-blind) studies to be effective in moderate depression but the problem is that what you can purchase otc (over-the-counter) is anybody's guess: you're trusting that what the bottle indicates it contains is actually what's in there. If one does decide to try it, one should be sure to let the pharmacist who fills your rx-s know, b/c there can be interactions. Just b/c something is "natural" doesn't make it benign.