Keratin is a protein naturally present in hair, but in a rinse-off shampoo it does not permanently rebuild or repair the hair structure from within. Dr.Sante Keratin Shampoo should be understood as a cleansing product with an added smoothing and conditioning effect, not as a treatment that reverses damage.
What it can do is help coat the outer surface of the strand during washing. When the hair cuticle lies flatter, the hair may feel less coarse, look less dull and be easier to detangle. This is why keratin shampoos are often chosen for brittle-looking, porous or frizz-prone lengths that need a smoother finish without a heavy feel.
For hair that is very dry, repeatedly bleached, heat-styled or prone to breakage, shampoo alone is usually not enough because it is rinsed away quickly. A matching balm, conditioner or mask can support the routine better because it stays on the hair longer and gives more time for conditioning ingredients to work on the surface of the lengths.