A hair care composition containing inorganic fluoride for straightening, smoothing, and/or relaxing hair, and a method for using the hair care composition a hair care composition containing an inorganic fluoride for straightening, smoothing, defrizzing, curling and/or relaxing of hair, and its method of use in a variety of hair care products, e.g., straightener solution, shampoo, conditioner, color binding treatment, volumizing treatment, a combination thereof, etc. The hair care composition is formaldehyde-free, even when heated.