Optimized tryptophan plus is made with L-tryptophan, as well as nutrients such as lysine, niacinamide and more to help maintain healthy tryptophan activity in the body. Serotonin is a neurotransmitter in the brain associated with positive mood and restful sleep. Body requires the essential amino acid tryptophan to produce and maintain healthy serotonin levels. But body cannot make tryptophan on itIngredients:Supplement Facts Serving Size 3 vegetarian capsulesServings Per Container 30 Amount Per Serving Niacin (as niacinamide) 66 mg L-Tryptophan 1000 mg L-Lysine (as L-Lysine HCl) 250 mg Perluxan Hops Standardized Extract (Humulus lupulus) (cones) and Ursole Rosemary standardized Extract (Rosmarinus officinalis) (leaves) Other ingredients: vegetable cellulose (capsule), maltodextrin, modified food starch, ascorbyl palmitate, silica, medium chain triglycerides.