You’ve heard of retinol, but have you heard of retinal? In the skin, retinol undergoes two sequential oxidative conversions to the biologically active form of Vitamin A, retinoic acid. Retinol is first oxidized to an aldehyde, aka retinaldehyde, which is then further oxidized to a carboxylic acid, retinoic acid. This natural conversion path makes retinaldehyde the closest active form of retinoid that is available without prescription.
Retinoids play a key role in the biology of vision and are known to regulate cell growth increasing cell renewal and helping increase collagen production for firmer and smoother skin texture.