Unlike your classic Olaplex No. 3 treatment, the No. 8 mask is made to be used on clean, damp hair in place of your conditioner. Wash your hair, then squeeze out as much water as you can. You’ll want two pumps for shoulder length hair, working up or down from there in terms of quantity depending on how much hair you have. Work the product through your hair, focusing on the lengths and ends, and leave it in for 10 minutes, then rinse.
If your hair is in particularly dire straits, you’re better off using this mask more frequently than you are leaving it on for longer.