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The two are often believed to be interchangeable, but the main difference is that retinol is eventually converted into retinoic acid. Retinol is a natural form of vitamin A, while Retin-A is derived from retinoic acid, a synthetic derivative of vitamin A, and considered pharmaceutical.
However, retinol is not as effective as prescription retinoids because itâs a less powerful form of vitamin A. 1  Getty Images Avoid Irritation Retinoids can be irritating, especially when you first add them to your skin care routine.2  So, you may want to start with an over-the-counter retinol to build up your tolerance.etinoids vs. Retinols. Retinoid is the prescription-strength form of vitamin A. Topical prescription retinoids such as tretinoin (Retin-A and Renova) work as an irritant, resulting in a more rapid turnover of skin cells.