CLAIM It works as well as professional keratin treatments and lasts up to 30 days. A caveat: It's designed for "specific hair types only," i.e., healthy, unprocessed hair ($13; at drugstores).
EXPERT OPINION "Though it has keratin, along with conditioners, it also uses potent chemicals like ammonia, peroxide, and thioglyco-late," Hammer warns. "That means it's not safe to use on hair that's been colored, straightened, or subjected to excessive heat styling."
OUR VERDICT Our virgin locks were left unscathed. It didn't make hair flatjust smoother and less frizzy.Read MoreLess