{"ok":true,"entry":{"slug":"histidine","kind":"supplement","name":"histidine","aliases":["L-histidine"],"brands_sg":["California Gold Nutrition","Life Extension","NOW Foods","Doctor's Best","Nutricost"],"class":"amino acid","tags":["general"],"use_for":"an essential amino acid · buffering and carnosine supply","use_after":null,"use_duration":null,"take_with":null,"pros":["essential — buffering, metal chelation, erythropoiesis","the precursor of carnosine","no toxicity or mutagenicity signs reported in review"],"cons":["liver disease — the review calls it inappropriate there","raises blood ammonia and glutamine, lowers bcaas","most claimed uses still need further study"],"dose_note":"the review read reports no established supplementation dose and calls for further study of histidine supplementation across the conditions it lists","dosage":{"ul":null,"unit":"mg","fda_dv":null,"rda_ai":null,"ul_status":"none_established","population":"general adult","hsa_max_daily":null},"ul_status":"none_established","sg_class":null,"cautions":["liver disease — the review states histidine supplementation is inappropriate in these patients","histidine is a histamine precursor, although allergic reactions have not been reported","hepatic enlargement and raised ammonia and glutamine were among the findings of concern"],"clashes":[],"sources":[{"id":"holecek2020","url":"https://europepmc.org/article/PMC/PMC7146355","label":"Histidine in Health and Disease: Metabolism, Physiological Importance, and Use as a Supplement (Holecek M, Nutrients 2020; PMC7146355)","quote":"L-histidine (HIS) is an essential amino acid with unique roles in proton buffering, metal ion chelation, scavenging of reactive oxygen and nitrogen species, erythropoiesis, and the histaminergic system.","accessed":"2026-08-27"},{"id":"holecek2020_carn","url":"https://europepmc.org/article/PMC/PMC7146355","label":"Holecek M, Nutrients 2020 — histidine derivatives and dipeptides","quote":"HIS-containing dipeptides (particularly carnosine), and methyl- and sulphur-containing derivatives of HIS … have specific functions.","accessed":"2026-08-27"},{"id":"holecek2020_gaps","url":"https://europepmc.org/article/PMC/PMC7146355","label":"Holecek M, Nutrients 2020 — evidence gaps","quote":"Further studies are needed to elucidate the effects of HIS supplementation on neurological disorders, atopic dermatitis, metabolic syndrome, diabetes, uraemic anaemia, ulcers, inflammatory bowel diseases, malignancies, and muscle performance","accessed":"2026-08-27"},{"id":"holecek2020_safety","url":"https://europepmc.org/article/PMC/PMC7146355","label":"Holecek M, Nutrients 2020 — reported safety signals","quote":"Signs of toxicity, mutagenic activity, and allergic reactions or peptic ulcers have not been reported, although HIS is a histamine precursor.","accessed":"2026-08-27"},{"id":"holecek2020_liver","url":"https://europepmc.org/article/PMC/PMC7146355","label":"Holecek M, Nutrients 2020 — findings of concern and liver disease","quote":"Of concern should be findings of hepatic enlargement and increases in ammonia and glutamine and of decrease in branched-chain amino acids … indicating that HIS supplementation is inappropriate in patients with liver disease.","accessed":"2026-08-27"},{"id":"epmc_his_search","url":"https://www.ebi.ac.uk/europepmc/webservices/rest/search?query=(TITLE:%22histidine%22)%20AND%20(TITLE:%22health%22%20OR%20TITLE:%22supplement%22%20OR%20TITLE:%22supplementation%22%20OR%20TITLE:%22review%22)%20AND%20(SRC:%22MED%22)&format=json&resultType=core","label":"Europe PMC REST search, 27 Aug 26 — histidine in title plus health/supplement/supplementation/review (83 hits; the human supplementation literature is almost entirely histidine-CONTAINING DIPEPTIDES such as carnosine and anserine, not histidine itself)","quote":"\"hitCount\":83 … \"Histidine-Containing Dipeptides in Obesity and Cardiometabolic Health: A Systematic Scoping Review.\"","accessed":"2026-08-27"},{"id":"hsa_hs_defn","url":"https://file.go.gov.sg/hsa-hs-guidelines.pdf","label":"HSA Health Supplements Guidelines GL-CHPB-3-001 Rev. No. 020 (January 2026) — s3.1 working definition and clause 4.8 (Tables 4-5 cover vitamins and minerals only)","quote":"Vitamins, minerals, amino acids, fatty acids, enzymes, probiotics and other bioactive substances … HS for use by the general adult population should not contain vitamins and minerals exceeding the stipulated limits stated in Tables 4 and 5.","accessed":"2026-08-27"},{"id":"hsa_pr_notlisted","url":"https://file.go.gov.sg/hsa-chp-prohibited-restricted-ing-guidelines.pdf","label":"HSA Guidelines on Prohibited and Restricted Ingredients in HS and TM, GL-CHPB-1-012 Rev. No. 001 (Oct 2025), Annex A/B — full text searched 27 Aug 26, no row for histidine","quote":"The objective of this guideline is to highlight the substances of concern when used in HS and TM and is not meant to be an exhaustive list.","accessed":"2026-08-27"},{"id":"iherb_sg","url":"https://sg.iherb.com/c/l-histidine","label":"iHerb Singapore category page \"Amino Acids\", default best-selling order, first 5 distinct brands — https://sg.iherb.com/c/l-histidine resolves to the general Amino Acids category listing; iHerb SG has no histidine-only category, so these brands are the amino-acid category's top sellers, not histidine-specific","quote":"Amino Acids","accessed":"2026-08-27"}],"brand_certs":null,"updated_at":"2026-08-29T16:16:21.812539+08:00"},"disclaimer":"kozen-x is not a medical device and does not give medical advice. it lists what published sources have written down. absence of a record is not the same as safe."}