Retinol is another name for a form of vitamin A. This can be confusing because the word "retinol" sounds like the tretinoin brand, Retin-A. Retinol is not nearly as effective as tretinoin, but medical studies have shown that stabilized forms of retinol do have some positive effects when applied to the skin.

The studies show that if the retinol penetrates, some may be converted by enzymes in the skin to small amounts of tretinoin, thereby producing similar effects such as improved collagen and a thickened epidermis.

See for example "In Vitro Metabolism by Human Skin and Fibroblasts of Retinol, Retinal and Retinoic Acid," Experimental Dermatology, 7(1), 27-34, 1998 Feb (abstract available on Medline).

Retinol can produce a modest reduction in fine lines and a somewhat smoother skin surface. Many retinol products are also inexpensive, so you can experiment with them without spending a lot of money. Net reviews of retinol products are generally positive, but reported results are usually quite modest and very gradual.

Many drugstores and grocery stores have non-prescription retinol products like Neutrogena Healthy Skin Anti-Wrinkle (regular and SPF15), Alpha-Hydrox ResQ , and philosophy Help Me Retinol Night Treatment. These are non-greasy, light creams that are usually applied at night. They cost about $11 for 30 to 40 grams. The regular Neutrogena product is the most widely available, and Wal-Mart also has a less-expensive store-brand called "Equate Anti-Wrinkle" for about $7 with similar ingredients.

Many retinol products are inexpensive compared to prescription tretinoin, and the medical studies indicate they can potentially improve your skin appearance. However, retinol products are less effective than those containing tretinoin. One dermatologist has said that currently-available retinol products are 5-10 times weaker in effect that 0.05% tretinoin.

While the medical studies on retinol used concentrations of approximately 1%, most retinol products don't list the retinol concentration. This is silly, but it is a common practice with cosmetics companies because it allows them to skimp on active ingredients. So you can't compare the potency of the products with those used in the studies. One well-known skincare expert has questioned whether the concentration of retinol in most products is as high as that used in the studies.

Using Retinol 

The instructions included with some retinol products say you can see results in a matter of weeks, but since tretinoin takes months for visible results, this is probably not true. In fact, based on the suspected low retinol concentration in most products, you might have to use it for a few years to get the same noticeable effect as with only six month's use of tretinoin. Because of this, there may not be any long-term cost savings over generic tretinoin.

Don't confuse retinol products with other skin creams that say "multivitamin" or list various other vitamins. Vitamins have to be in certain chemical forms to penetrate the skin or cause any significant biological effect, and most skin products do not contain these vitamin forms.

In addition, unlike retinol and tretinoin, there is no conclusive evidence yet that other types of vitamins improve collagen or elastin. (There have been a few preliminary studies on special forms of vitamin C, but the evidence for beneficial effects is very limited.)

Retinol products are safe for continuous use because they are equivalent in effect to very low-concentration tretinoin creams. However, some brands may have other irritating ingredients, so start by using only a small amount, and see how your skin reacts. Like tretinoin, the directions on most of these products say they should be used only at night, but supposedly Neutrogena's SPF 15 version can be used outside during the day.

Retinol products do degrade over time and lose potency after about three years. Unfortunately, most products do not have expiration dates stamped on the tubes. Since products can sometimes sit in warehouses and on store shelves for up to two years, it is best to only buy one tube at a time.