Used in cell culture media as an essential amino acid to support cell growth and protein synthesis. Commonly added to pharmaceutical formulations to stabilize proteins and peptides due to its buffering capacity near physiological pH. Employed in parenteral nutrition solutions to meet amino acid requirements in patients unable to take oral nutrition. Also utilized in research settings for studying histidine metabolism, metal chelation, and its role in immune function. Serves as a precursor in the synthesis of histamine, a key molecule in immune responses and neurotransmission.