Maxi L-Tryptophan 500™Maxi L Tryptophan 500 is a supplemental source of l tryptophan. What is l rryptophan? Its an essential amino acid your body needs to function properly. But you have to get tryptophan through your diet or supplements because your body can't make it. Tryptophan can supports increased brain levels of both serotonins and melatonin. They enable a calm frame of mind and sleep respectively. Try Maxi L Tryptophan 500.