Strengths: The active ingredients (most contain tretinoin) have mounds of research establishing their multiple anti-aging benefits for skin (particularly sun-damaged skin). Tazorac contains the active ingredient tazarotene, a retinoid that works similarly to tretinoin.
Weaknesses: Some people cannot tolerate tretinoin therapy; all of these products require a prescription; textures of each are not nearly as elegant as using a well-formulated moisturizer.
Note that your actual price for these prescription products will vary based on your health insurance coverage, if any, and whether or not your physician believes that a generic form of tretinoin is an equally effective (and hence less costly) option.
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.