A great Treatment to strengthen & give a little extra care to hair. I have thick hair that gets dried out, weakened & a little frizzy from highlights & this little vial of goodness, really strengthens it & makes it look & feel healthy again. I also use the Kerastase Boosters w this. So great tht I don't even need to condition my hair after using this, just a little Kerastase Oleo Serum after I towel dry. I've been using it for a few yrs now. It’s pricey But definitely worth buying and doing it yourself than paying 3-4x's the price for this Treatment at the Salon!! I alternate between all the Kerastase Treatments & Boosters & they're all great!!