It's original Prell shampoo- but it in your dry hair, throw on a shower cap and leave in for 45 minutes. I blow dried it on high heat every now and then (as I heard heat enhances the process). Then...
Three days a go I dyed my medium, dark brown hair with a black semi-permanent dye (lasts 28 shampoos) and it turned way too black. I tried washing it out with a clarifying shampoo and the Prell...