Retinoids are an important topic to discuss when it comes to skin care. Retinoids are a general term referring to a vast range of ingredients derived from vitamin A (retinol is the technical name for vitamin A). Retinol is a cosmetic ingredient while other retinoids such as tretinoin (the general term is all-trans retinoic acid or just retinoic acid) or adapalene (the active ingredient in Differin) are prescription-only topical ingredients. Prescription-only, topically applied retinoids are significant for skin because they can positively affect the way cells are formed deep in the dermis. If you have sun-damaged, dry, wrinkled, or acne-prone skin, you should become familiar with the prescription-only product names Retin-A (all types), Renova, Differin, Avita, Retin-A Micro, Refissa, and Tazorac, which all contain different forms of retinoids. The active ingredient in Retin-A, Avita, Refissa, and Renova is tretinoin, Differin uses adapalene, and Tazorac uses tazorotene. In fact, Refissa, Renova and Tazorac have been approved by the FDA for the treatment of wrinkles. Retinol is a cosmetic ingredient, and when it is absorbed into skin it can become the more active form of all-trans retinoic acid, making it a cosmetic alternative to prescription options. Different forms of retinol, in descending order of potency in cosmetics, are retinol, retinylaldehyde (also referred to as retinal), retinyl palmitate, retinyl propionate, and retinyl acetate. (Sources: Clinics in Dermatology, November-December 2008, pages 633–635; American Journal of Clinical Dermatology, November 2008, pages 369–381; Journal of Drugs in Dermatology, July 2008, pages S2–S6; Harvard Women’s Health Watch, September 2007, pages 6–7; Archives of Dermatology, May 2007, pages 606–612; Clinical Interventions in Aging, 2006, volume 1, issue 4, pages 327–348; Dermatologic Surgery, June 2004, pages 864–866; Archives of Dermatology, November 2002, pages 1486–1493; Clinical and Experimental Dermatology, October 2001, pages 613–618; and www.fda.gov). Note that retinoids are not exfoliants, though many people think that’s what they do. Exfoliants such as AHAs and BHA primarily affect the top layers of skin, improving its appearance, integrity, and protection potential. They also help improve the function of the pore. In contrast, retinoids affect the lower layers of skin (dermis), where new skin cells are produced. Retinoids actually communicate with a skin cell as it is being formed, telling it to develop normally instead of developing as a sun-damaged or genetically malformed skin cell. Why the confusion about the effect retinoids can have on the skin? Primarily it’s due to the fact that products containing retinoids, and even the milder form retinol, can cause irritation and inflammation, resulting in the skin becoming flaky and dry. This flaking and dryness is not exfoliation, nor is it a desirable or advantageous result. If retinoids cause your skin to be consistently dry and flaky, it is a problem and you should probably avoid products that contain it, reduce how often you use them, or consider a retinoid product with a lesser potency. Despite the valuable effect retinoids can have for skin, don’t expect them to “erase” wrinkles. That’s because, while the improvement is impressive and the improvement in the overall function of skin cells is notable, it is neither dramatic nor superior to surgery or medical cosmetic corrective procedures. However, if skin cells can be produced with a healthier form and shape, the skin’s surface will have a smoother appearance, skin cells will do their job of turning over in a more normal fashion, the protective outer layer of skin will remain intact, enhancing the skin’s healing response, and on and on. In essence, the skin will behave and look the way it did (to some extent) before it was damaged by the sun. Regardless of these positive effects, retinoids will be useless, and the skin will be prone to more damage, if you do not wear a sunscreen as well. Not a wrinkle cream in the world, even one approved by the FDA, can have positive results if you don’t use an effective sunscreen; without that, you are just adding to damage you already have accumulated. What retinoids, AHA, and BHA products have in common is that once you stop using them, your skin will revert to the way it was before. These products will not produce permanent change. The smooth exterior lasts only as long as you use them. Yet when used together, long-term, they are a formidable weapon in the battle against wrinkles and blemishes. The price for these products varies by size, strength, and what your individual health insurance prescription coverage may be.
All of the products in the heading above are prescription-only drugs belong to a class of active ingredients called "retinoids." Although I do not review these products as I do other products, all of them deserve mention on Beautypedia. That’sbecause, depending on your needs and preferences, each has merit for helping skin in numerous ways. Whether your concern is acne, sun damage, wrinkles, loss of firmness, or simply creating and maintaining healthier skin, retinoids are a state-of-the-art, multipurpose treatment. Furthermore, unlike countless cosmetic ingredients and all manner of anti-aging products that make fantastic claims, retinoids are backed by mounds of solid research supporting their mechanism of action, efficacy, and tolerability (Sources: Cutis, December 2006, pages 426–432; Drugs, 2005, pages 1061–1072; Dermatologic Therapy, Sep-tember–October 2006, pages 297–305; The Journal of Family Practice, Novem-ber 2006, pages 994–996; and Cutis, October 2004, pages 4-8).
With regard to the active ingredients in these products, tretinoin (found in Retin-A, Avita, Refissa, and Renova) has been around the longest and has the most research behind it. Considered a "first-generation retinoid," tretinoin improves skin-cell function, changing abnormally produced cells into ones that are more normal, which in turn changes the environment of the pore and makes it more difficult for blemishes to form.
Tolerance is a big issue with tretinoin, as its side effects (burning or stinging sensations, peeling, and redness) can be bothersome and visually discouraging, not to mention difficult to camouflage with makeup (Source: Journal of Drugs in Dermatology, November-December 2004, pages 641-;651). How much (or even if) these side effects will be an issue depends greatly not only on the concentra-tion of tretinoin but also on the vehicle (cream, gel, lotion), frequency of application, and each individual's reaction. Tretinoin in the form of Retin-A Micro seems to be less potentially irritating than "regular" tretinoin (Retin-A cream), which is likely due to Retin-A Micro's controlled delivery system (Source: Cutis, July 2003, pages 76–81).
Tazarotene is the active ingredient in Tazorac. It is a synthetic retinoid that works as a cell-communicating ingredient (similar to tretinoin) while normalizing skin-cell production and shedding within the pore lining. Tazarotene also has an anti-inflammatory effect and is frequently used in psoriasis therapy, often with a topical corticosteroid (Sources: American Journal of Clinical Dermatology, June 2005, pages 255-272; and Journal of the American Academy of Dermatology, August 1997). Side effects of tazarotene are similar to those of tretinoin, includ-ing a burning sensation, peeling, and redness. Just as with tretinoin, these side effects typically diminish or resolve with ongoing use as the skin adapts to the active ingredient.
Adapalene is the active ingredient in Differin. Clinical trials have shown that it causes fewer side effects and is thus better tolerated than tretinoin (Sources: International Journal of Dermatology, October 2000, pages 784-788; Journal of Cutaneous Medical Surgery, October 1999, pages 298-301; and Skinmed, September/October 2006, pages 219-223). Adapalene appears to have a particularly precise ability to positively affect the skin-cell lining of the pores, substan-tially improving exfoliation, which helps prevent blockages that can, in the presence of certain bacteria (P. acnes) lead to acne (Sources: Journal of Drugs in Dermatology, June 2007, pages 616-622; Journal of the American Academy of Dermatology, July 2007, Epublication; and European Journal of Dermatology, January/February 2007, pages 45-51).
Regardless of which prescription retinoid you choose, each has documented benefit for skin as well as its share of side effects that, for most patients, resolve with continued (and often modified frequency of) use. Those considering a retinoid for acne should keep in mind that although using a retinoid alone can be very helpful, many dermatologists recommend combination therapy to keep acne under control. This may involve prescription topical antibiotics or over-the-counter disinfectants. Finally, all forms of prescription retinoids increase the skin's sensitivity to sunlight. It is critical for the health of your skin (and even more imperative if you're using a retinoid) that you protect skin every day with a product rated SPF 15 or higher that supplies reliable UVA protection, in order to reduce or forestall the signs of aging.