I have long thick dry wavy/straight hair and I can use this on it damp or dry and it doesn't weigh it down. A few drops through my ends when it's damp and a drop through my dry hair after I have styled it for healthy soft locks. Even good on second and third day hair. The only downside is that it doesn't have the most pleasant scent, I think it's the atlas cedar essential oil. But it's tolerable and I use their hairspray as a finisher which does smell nice and covers it up.
I was using argan oil prior to finding this gem of a brand, which also worked well but I think this serum is an even better natural product.