Picamilon is a “compound formed by reacting naicin with GABA ((http://en.wikipedia.org/wiki/Picamilon)).” It helps in activating the GABA transmitters, which has been shown to lower stress levels.
The little research that I found on Picamilon seemed to be supportive of its claims to reduce stress and anxiety. For me, however, I would like to see alot more definitive research done.
Does lower stress correlate directly with weight loss? No. Is it helpful? Yes. Diet pills will include Picamilon in order to counteract the stimulants that may be in the diet pill as well (much like L-Theanine). Some stimulants often cause subjects to have adverse side effects such as nervousness and the jitters. Picamilon is meant to soften those side effects by reducing the amount of “stress” that you encounter.
So like many diet pill ingredients, Picamilon by itself won’t cause you lose weight at all. But it may be helpful if your diet pill has stimulants such as caffeine. Picamilon is beleived to be effective in stress reduction. Will it effectively get rid of any jitters from the stimulants in some diet pills? That has yet to be determined, but that is the hope of diet pill makers.