Science
Mechanism of Action
This dipeptide serves as a precursor for L-histidine, which is subsequently released upon enzymatic cleavage within the skin. L-histidine functions as a potent humectant, effectively drawing and retaining moisture to significantly enhance skin hydration and reduce transepidermal water loss. It fortifies the skin barrier by potentially increasing levels of trans-urocanic acid (UCA), thereby restoring the optimal pH crucial for barrier maintenance and repair. Furthermore, L-histidine provides antioxidant defense, aids in collagen synthesis, helps regulate skin pH, diminishes inflammatory responses, and supports the skin's intrinsic repair and recovery mechanisms. Its conversion to trans-urocanate in the skin, followed by conversion to cis-urocanate upon UV exposure, may also offer protective properties.
Research
Clinical Evidence
Low confidenceN/A
Transparency
Dusting Analysis
The Formula
Formulation
Stability
Tyrosine- and histidine-containing dipeptides are highly soluble in water and demonstrate general stability within a neutral pH range. Histidine, a key constituent, acts as an effective buffering agent, with optimal efficacy between pH 5.5 and 6.5, extending its buffering capacity to the pH range of 5.0-6.9 in formulations. The imidazole side chain of histidine has a pKa of approximately 6.0.
Conflicts
- high concentrations with stainless steel at elevated temperatures
- polysorbates (specifically in histidine buffer systems)
Safety
Safety Profile
A dedicated safety assessment for Tyrosyl Histidine HCl by the Cosmetic Ingredient Review (CIR) Expert Panel, Scientific Committee on Consumer Safety (SCCS), or FDA has not been identified. While its component, Histidine HCl, is listed in the CIR Portal Ingredient Status Report, specific details regarding its safety status were not ascertainable from the available information.
Your Skin
Skin Compatibility
Our Assessment
Verdict
Tyrosyl Histidine HCl is a valuable ingredient, anticipated to enhance skin hydration, support barrier function, and offer antioxidant benefits through its L-histidine component, though specific clinical data on the dipeptide itself is limited.
Related
Similar Ingredients
Finding similar ingredients…
References
Sources