I have fine, thin hair, porous that will frizz if it is even slightly humid. I bought Phytodefrisant based on all the great reviews out there. Sadly, this product did not work for me, at all. I will say, that in the absence of humidity, this leaves my hair looking sleek, but somewhat dry. Well, today was fairly warm and humid (for the end of January...), so I loaded some of this in my hair and headed out the door. When I got home a few hours later, after being outside most of this time, my hair looked like cotton candy, it was so frizzy. I can't imagine this being effective at all in the summer when it's really humid. Waste of money, for me.