The main Vitamin A Derivatives types used in cosmetic prodcuts include Retinol, Retinal (Retinaldehyde),Retinoic Acid(Tretinoin),Retinyl Palmitate, Hydroxypinacolone Retinoate(HPR). They are mainly used in Anti-aging, Anti-wrinkle, anti-acne,soothing, repairing, birightening and moisturizing other skin care products. 

Retinoic Acid is also named Tretinoin. Retinoic Acid is the carboxylic acid form of retinol (vitamin A).The collective term for all forms of vitamin A is retinoids.All retinoids need to be converted to Retinoic Acid by chemical rections in our skin to function.

Retinoic acid is synthesized from retinol via two enzymatic reactions, the first of which is a reversible oxidation of retinol to retinal, which is followed by a second and irreversible oxidation reaction to retinoic acid.