Trend Retinal Is the New Retinol Pitch K-beauty boosters are selling retinaldehyde as a faster, still-approachable vitamin A step. Retinal serums from MEDITHERAPY and celimax are part of a wider “not quite prescription, not basic retinol” pitch. Pair with sunscreen. Not medical advice. Related in this trend Ingredient Retinaldehyde (Retinal) C20H28O Ingredient Retinyl Retinoate C40H56O2 Ingredient Bakuchiol C18H24O Ingredient Retinol Retinol — C20H28O