Dr.Sante Keratin Shampoo is a good match if your main concern is the feel and appearance of the hair lengths: roughness, dullness, fluffiness, flyaways or tangling after washing. The product is designed to cleanse while also giving a conditioning effect, so it is most relevant when hair feels porous or brittle-looking rather than simply oily at the roots.
It may be useful if you regularly blow-dry, straighten, colour your hair or wash it often, because these routines can make lengths feel less smooth. In this shampoo, keratin is used for a surface-smoothing effect: it can help the cuticle lie flatter, which may make hair feel softer, reflect light more evenly and comb through with less friction when wet.
If your hair is very fine or becomes flat easily, start with a small amount and focus the lather mainly on the scalp, letting the foam rinse through the lengths. If your scalp is very sensitive or easily irritated, monitor how it responds and adjust how often you use the shampoo if needed.