A hair moisturizing topical composition comprising materials that emit electromagnetic radiation at wavelengths that affect tertiary structure (breaking of disulfide bonds) in human hair, and that bring about changes in secondary structure of hair proteins. The intensity of the radiation is controlled and sufficient to cause or facilitate altering of protein structure. The invention includes methods of using such topical compositions. Testing indicates that the level of tightly bound water in hair is increased, and there is no damage to hair of the type characteristic of heat and chemical treatments.