I have thin, Scandinavian hair and a sensitive scalp, so products that go on the scalp have always been a bit difficult for me. My hair also tends to get a bit dry in the lengths.
I have been using Kérastase Genesis Serum Anti-Chute Fortifiant for about 5 weeks and it has worked well for me. The serum feels light, doesn't get sticky, and my scalp hasn't reacted. I feel like my hair feels a bit stronger and I'm losing less hair, even though it's early and hard to say exactly how much.
I have also used Kérastase Nutritive 8H Overnight Serum during the same period. It has made my hair easier to brush and I no longer get as many tangles in the morning. The lengths feel softer and my hair looks shinier. For me, both products have worked well, especially considering my hair type.