The L-Tryptophan amino acid is a precursor of melatonin The L-Tryptophan amino acid is a precursor of serotonin L-Tryptophane is a versatile essential amino acid that the body cannot produce, or can only produce in insufficient amounts. L-tryptophan is easy to replace with a balanced diet and good quality nutrients. Duck, pork, cottage cheese, and eggs are rich in L-tryptophan. If you want to cover your L-tryptophan intake from other sources as well, then you should take the BioTechUSA L-Tryptophan dietary supplement capsules. Thanks to its capsule form, it is easy to portion out and take with you anywhere during the day. Who do we recommend the product BioTechUSA L- Tryptophan for? for those who need the supplementation of L-tryptophan essential amino acid for those looking for a capsule product Essential amino acids Essential amino acids (9 types of which we know) are essential for the human body because they are not or only insufficiently produced by the body. That is why it is particularly important to supply them from external sources, preferably in the optimal amount and proportion. L-tryptophan is also an essential amino acid that performs many functions in the body, it also serves as a precursor of serotonin and melatonin. L-tryptophan, like any other BioTechUSA product, contains safe, carefully selected ingredients.