Arginine

Arginine is a semi-essential amino acid (adults can synthesize it, but infants cannot) and a primary building block of hair keratin and skin collagen. It is classified as a natural moisturizing factor and carries a positive (cationic) charge, making it substantive to skin and hair surfaces, which are more negatively charged. Its positive charge also enables it to form complexes with AHAs, creating a time-release AHA effect and reducing associated irritation.