Beauty Glossary: F

Fatty acids - used chiefly in shampoos, cleansers and conditioners to make the skin feel smooth and the hair easier to comb. Common ones include cetyl alcohol, coconut alcohol, stearyl alcohol, and oleic acid.

Fatty alcohols - alcohols that are emollient, not drying. They are used in creams, conditioners, lotions, and shampoos. Common ones include cetyl alcohol, oleyl alcohol, lauryl alcohol, and stearyl alcohol.

FD&C dyes - coloring agents used in cosmetics that are usually made from coal tar.

Folliculitis an inflammation of the hair follicle that looks like a rash and is usually found in areas of the body where skin has been irritated by shaving or waxing; also called razor bumps.

Formaldehyde - an ingredient in some nail polishes and glues, it is a known allergen and suspected carcinogen.

Free radicals - a molecule that damages normal, surrounding cells by depleting them of oxygen.

Fruit acid peel - a facial peel using alpha-hydroxy acid.

Fucus - brown algae rich in antioxidants that are used in algotherapy.