Straightening Serum is a non-greasy, weightless formula that instantly straightens the hair while eliminating frizz and enhancing shine with a smooth, silky touch. This formula's key ingredient is Hydrolyzed Silk Protein, which is derived from one of the strongest natural fibers in the world. Hydrolyzed Silk Protein forms a crystalline protective barrier on strands improving hair's elasticity and manageability. Straightening Serum provides protection against heat styling, humidity, and UV damage. Along with its key ingredient Straightening Serum contains HE Synergy Botanical Blend. It provides heat styling, humidity, and UV protection. Apply from roots to ends on wet hair and straighten with blow dryer. May be applied to dry hair using a flat iron to finish.