Menaquinone-7

// Evidence: Anti-sebum ingredients modulate sebaceous gland activity through inhibiting 5α-reductase enzyme, regulating lipogenesis in sebocytes, or absorbing surface sebum. Active ingredients include zinc salts, botanical extracts (saw palmetto, green tea), niacinamide, azelaic acid, and retinoids. These compounds may reduce sebum synthesis, decrease sebocyte proliferation, or normalize keratinization in pilosebaceous units.

// Evidence: Astringents cause temporary contraction of skin tissues through protein coagulation and precipitation. Common astringents include alcohol, witch hazel (containing tannins), alum (aluminum potassium sulfate), and plant tannins. The mechanism involves inducing vasoconstriction, precipitating proteins in cell membranes, and denaturing surface proteins which creates temporary tightening sensation.

// Evidence: Bleaching agents oxidize chromophoric structures, breaking down pigments into colorless compounds. Hydrogen peroxide is the primary oxidizer for hair bleaching, working with alkaline boosters to swell the cuticle and oxidize melanin pigments. For teeth, peroxides penetrate enamel and oxidize chromogens. Skin lightening involves inhibiting tyrosinase enzyme to reduce melanin synthesis.

// Evidence: Skin protecting ingredients defend against environmental stressors, irritants, and damage through barrier enhancement, antioxidant activity, anti-pollution effects, or physical barriers. Include dimethicone (barrier), allantoin (soothing protectant), zinc oxide (physical protectant), and film-formers. Mechanisms vary: forming protective films, neutralizing oxidative stress, chelating pollutants, strengthening barrier function. Used in protective creams, barrier treatments, and defensive skincare against urban pollution, extreme weather.