So if you're dealing with dandruff and want something that actually works while you sleep, check out the Kérastase Symbiose Anti-Dandruff Night Serum. It's pretty genius, honestly – your scalp does most of its healing at night anyway, so why not give it some extra help? This stuff has salicylic acid and piroctone olamine in it, which basically go after what's causing the flakes in the first place and help your scalp breathe better.What's cool is it doesn't have any sulfates or silicones, so it's not harsh on your scalp at all. They added bifidus extract too, which calms down any itchiness or irritation and can keep dandruff away for up to seven weeks. The texture's kind of interesting – it starts clear then turns milky when you work it in – and it smells really nice, not medicinal or anything.Using it is super easy. Just put 3 to 4 pumps right on your dry or towel-dried scalp, work through it section by section with your fingers, and you're done. No rinsing needed. Just hit the pillow and let it do its thing overnight. You'll notice your hair looks way healthier and the flakes are gone.