HisHistidineopen_in_newamino acidHistidine is an essential amino acid involved in protein synthesis, tissue repair, and the maintenance of nerve-protecting myelin sheaths. It is a precursor to histamine and carnosine and supports immune response, digestion, neurotransmission, and heavy-metal chelation.$28.90 median price$0.83 per serving$0.12 per 10 mg76 mg per serving Show details expand_more