Histidine

As an amino acid, histidine has been thought of as semi-essential because while the body synthesizes some, additional amounts are required through the diet in order to not deplete essential amino acids for the synthesis of it. In any case, it is truly important for the development of various physiological functions, especially in immune defense, allergic responses, and the regulation of inflammatory pathways.
Histidine in skincare is noted for its hydration properties. It helps in keeping water inside the skin, a feature that is desirable for better hydration to take place and is followed by an improvement in softness and elasticity. Thus, histidine contributes to good hydration, supports the skin barrier, and in turn sustains health and resilience in the skin.
It could also have a protective function, such as protection from environmental aggressions and cutaneous infections. Given that histidine participates in immune regulation, it is likely to render the skin more sensitive against irritation and pathogens; thus, it would be useful in products for sensitive or reactive skin.
In addition, it contains anti-inflammatory properties, making histidine useful in calming irritated skin or inflammation; this is particularly helpful in product formulation for sensitive or blemish-prone skin. The capacity of histidine to modulate both immune response and inflammation further extends the role of histidine in skin health beyond mere moisturization.
Histidine can also be described as an amino acid that is semi-essential, playing a supportive role with regard to immune function and inflammation, and serving the function of enhancing hydration in the skin. Its potential protective action against infections further soothes irritation. This versatility in its action makes this ingredient versatile in the formulation of skincare products whose claims are mainly moisturizing and soothing for sensitive skin.