Retinol is a specific form of vitamin A that is naturally produced in your body. When it’s applied topically, enzymes in your skin convert retinol into retinaldehyde and then into retinoic acid. Because of the two-step conversion that it has to undergo before the skin can use it, retinol is naturally gentle; this means that while the results are slower, it has fewer side effects. The conversion into retinoic acid can take at least a few weeks, which is why you should use retinol products consistently for a few months before expecting to see results.
In addition to “Vitamin A,” retinol products go under many different names on product labels, including retinyl palmitate, retinyl acetate, retinyl linoleate, retinaldehyde, tazarotene, retinol and retinoic acid, isotretinoin or tretinoin.