Stylist Tiffany Vance, owner of Hedda Hair and Body Bliss in Joliet, Ill., began doing the chemical service in June.

"I've had extremely good results," Vance says. "It's good for all curl types, especially those who color their hair."

A big selling point of BKT is that it doesn't have the strong chemicals - sodium hydroxide and ammonium thioglycolate - that are in most relaxers and straighteners. These harsh chemicals can cause damage and breakage.

Instead, the active ingredient is keratin, a protein similar to a component in human hair, which naturally straightens the hair. Unlike many chemical processes, Brazilian Keratin Treatment works best on hair that's been color processed, highlighted or chemically treated.