How does the two-step oxidative system work and why does it last longer than regular tint?

The product uses an oxidative dye system: you mix the color cream with a hydrogen peroxide developer (sold separately) in the ratio specified in the instructions. This chemical reaction creates pigment molecules that penetrate into the hair cortex rather than merely coating the cuticle. That internal deposition is why the color withstands washing, sweat, and friction for several weeks — typically 4–6 weeks on brows and 3–4 weeks on lashes — while wash-off tints or mascaras rinse away in a day. The ammonia-free formula reduces the harsh smell and irritation risk common with traditional oxidative dyes, and the added castor oil helps condition hairs during the process so they feel less brittle afterward. For the reaction to work correctly, you must measure both parts precisely and mix thoroughly; eyeballing the ratio leads to uneven development or a shade that shifts too warm or too cool.