Contains the unique Tri-Phase Complex which targets all three stages of the hair growth cycle. Helps retain, activate and maintain. This powerful, revolutionary skin care-inspired formula treats at the root promoting the appearance of stronger, denser, thicker, fuller and more luscious looking hair. Developed for thinning, lifeless, damaged hair due to age, over processing, hormonal changes, stress, etc. Concentrated, weightless formula absorbs quickly into the scalp. Safe, effective, drug-free. Safe for color and chemically treated hair. For great results, pair with Peter Thomas Roth's Mega-Rich Shampoo and Conditioner.