L-Tryptophan 180 Caps by Nutri+ provides high-purity L-tryptophan, an essential amino acid that cannot be produced by the body and must be obtained through diet or supplementation. This product serves as a precursor to serotonin, known as the "happiness hormone," and melatonin, which regulates the sleep cycle. Each daily dose provides 500 mg of L-tryptophan in vegetable capsules.