Histidine
Amino acid; precursor of urocanic acid, a UV-protective stratum-corneum component. Functional formulation ingredient with no standalone activity on the skin.
Evidence by route
Topical application
Inert formulation ingredient. Safe, no standalone activity.
How to read tiers A–F
- CWeak evidence. In vitro data, open-label studies, or expert consensus
Tolerability and safety
- Irritation potential
- Low
- Allergen risk
- Low
- Pregnancy
- Safe
About this ingredient
Histidine is an essential amino acid, precursor of urocanic acid (UCA) – a natural UV filter of the stratum corneum. UCA forms by histidase-mediated deamination of histidine and absorbs UVB in the 290-310 nm range. Where applied. Moisturizing creams and serums as part of NMF amino acid cocktails (0.1-1%). Rarely used alone – usually in blends with pyrrolidone carboxylic acid, serine, alanine, threonine. Evidence base. Histidine and its metabolite UCA protect skin from UVB by absorbing photons. However, isomerization to cis-UCA activates immunosuppression (Norval 2010) – a potentially undesirable effect. Few direct clinical studies of topical histidine; the cosmetic function is as an NMF component without standalone active claims. Safety. CIR confirmed safety. Hypoallergenic, non-comedogenic. Pregnancy and lactation – safe.
Frequently asked questions
Is Histidine safe during pregnancy?
Histidine is considered safe during pregnancy at typical cosmetic concentrations. Systemic absorption through the skin is minimal.
What is Histidine and what does it do in cosmetics?
Amino acid; precursor of urocanic acid, a UV-protective stratum-corneum component.
What's the INCI name for Histidine?
The INCI name is Histidine.
See Histidine in a product composition right on the store page
The Evigrade extension adds an evidence panel to iHerb, Sephora, Druni and 12 more stores. This ingredient and every other one in the product show evidence-tier, allergen risk and pregnancy/lactation flags at a glance.
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Histidine HCl, Hizikia Fusiforme Extract, Homarine HCl, Honey Extract, Lupinus Albus Seed Oil, Apricot Kernel Oil, Agave Tequilana Leaf Extract, Collagen
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