Abstract: Quaternized hemp seed oil is incorporated into cosmetic compositions, such as shampoos, hair conditioners, hair sprays, mousses, gel or sculpting lotions, pomades, and skin creams and lotions. The hemp seed oil is saponified and quaternized under gentle conditions, and in the substantial absence of oxygen, to avoid oxidation and cross-linking of essential fatty acids that provide biological benefit to the hair and skin. In a disclosed embodiment, saponification occurs in the presence of an alkali hydroxide catalyst, under a blanket of nitrogen gas at subatmospheric pressures. Subsequent quaternization is performed with a tertiary amine of the formula ##STR1## wherein R.sub.1 and R.sub.2 are each lower alkyl, and R.sub.3 is aliphatic alkyl having 8 to 22 carbons. In a specific embodiment, the quaternizing agent is dimethylcetylamine.