- Kopple JD et al, 1975, Evidence that Histidine is an Essential Amino Acid in Normal and Chronically Uremic Man The Journal of Clinical Investigations
- Histidine Natural Medicines Comprehensive Database
- Histidinemia Genetic Home Reference
- Metabolism of histamine European Histamine Research Society
- Amino acids Imgt.org
- Cooperman JM et al, 2002, The role of histidine in the anemia of folate deficiency PubMed
- Carnosine NYU Langone Medical Center
- Amino acid ChemPep
- List of foods high and low in histidine US Deparment of Agriculture
What is histidine?
Histidine abbreviation (symbol): His
Histidine Functions in the Human Body
- A building block of proteins
- A precursor of the neurotransmitter histamine  and, together with beta-alanine, a precursor of the dipeptide carnosine .
- A glucogenic amino acid — it can be converted into glucose 
- A basic (pH >7) amino acids (together with arginine and lysine) 
Foods High in Histidine
- ANIMAL FOODS: pork, beef, chicken, turkey, fish, cheese 
- PLANT FOODS: legumes 
Foods low in histidine: wheat, fruits, vegetables 
Oral L-histidine supplements are available without prescription (over-the-counter).
Possible Histidine Health Benefits
Histidine is POSSIBLY INEFFECTIVE in  :
- Relieving pain in rheumatoid arthritis
- Improving anemia associated with a kidney disease or hemodialysis
There is INSUFFICIENT EVIDENCE about the effectiveness of histidine supplements in the prevention or treatment of anemia due to folate deficiency , allergies and ulcers  or in increasing muscle power or athletic performance.
Histidine Safety: Side Effects, Toxicity
Histidine supplements, when taken by mouth in recommended doses, are POSSIBLY SAFE for most people .
Side effects of doses up to 4 grams per day are not known .
Not enough studies have been done about the safety of histidine supplements during pregnancy and breastfeeding, so women in these periods should avoid them .
Individuals with folic acid deficiency should also avoid histidine supplements because they can cause accumulation of the metabolite formiminoglutamic acid in the body .
Histidinemia is a rare inherited disorder with increased levels of histidine in the blood and urine due to lack of the enzyme that breaks down histidine. The affected individuals usually have no symptoms and do not need any diet restrictions or therapy .