Large group of over 2,500 chemicals related to vitamin A. Topical, over-the-counter retinoids include retinol, retinyl palmitate, retinaldehyde, and retinyl linoleate, among others. Prescription retinoids include tretinoin (Renova, Retin-A), adapalene (Differin), and tazarotene (Tazorac). Other retinoid chemicals include beta-carotene and various carotenoids found in brightly colored and dark green fruits and vegetables. [1, 2, 3, 4]
When applied topically, retinoids function in multiple ways. Primarily, they work as cell-communicating ingredients, essentially connecting with a receptor site on a skin cell and “telling” it to behave in a more normal and healthier manner. Retinoids have benefits for more than 125 different skin issues, from acne to psoriasis to wrinkles and other signs of sun damage. They can improve, to some extent, how new skin cells are formed and how they behave as they mature (differentiate) and make their way to the skin surface. Tolerability can be an issue with all retinoids, with the prescription forms more likely to cause side effects than over-the-counter retinol products. The most common side effects from topical application of retinoids include irritation, flaking skin, and redness (sometimes resembling and/or feeling like sunburn, with skin being tender to the touch). [3, 4] The side effects tend to appear within 2–4 days from the time you apply the retinoid. In most cases, they subside within a few weeks as your skin adjusts; however, there will always be some people whose skin is simply intolerant of retinoids.
It’s important to avoid applying too much of any retinoid product; more isn’t necessarily better and can often make the potential side effects an unwelcome reality. For example, the directions for prescription retinoid creams state to apply a pea-size amount, which is plenty. Applying more per use won’t get you better or faster results, but it can increase the chances of unwanted side effects.
Research has shown that varying strengths of retinol and prescription retinoids are beneficial; with any type of retinoid, the “if a little is good, more must be better” mentality can backfire. Some people’s skin can tolerate higher amounts of retinoids, but it’s always best to begin with the lower strength to see how your skin responds and then increase the concentration if results are positive. It’s also fine to alternate between lower- and higher-strength retinoid products; for example, one night you can apply an over-the-counter retinol product, and the next evening apply a prescription retinoid. [1, 2, 3, 4]
- Rossetti D, Kielmanowicz M, Vigodman S, Hu Y, Chen N, Nkengne AOT, Fischer D, Seiberg M, Lin C. A novel anti-ageing mechanism for retinol: induction of dermal elastin synthesis and elastin fibre formation. Int J Cosmet Sci. 2011;33(1):62-9.
- Thomas J, Dixon T, Bhattacharyya T. Effects of Topicals on the Aging Skin Process. Facial Plast Surg Clin North Am. 2013;21(1):55-60.
- Mukherjee S, Date A, Patravale V, Korting H, Roeder A, Weindl G. Retinoids in the treatment of skin aging: an overview of clinical efficacy and safety. Clin Interv Aging. 2006;1(4):327-348.
- Kang S, Duell E, Fisher G, Datta S, Wang Z, Reddy A, Tavakkol A, Yi J, Griffiths C, Elder J, et al. Application of retinol to human skin in vivo induces epidermal hyperplasia and cellular retinoid binding proteins characteristic of retinoic acid but without measurable retinoic acid levels or irritation. J Invest Dermatol. 1995;5(4):549-56.