Elsewhere on this site I mention that many if not most retinol creams have no or little effect on wrinkles and skin texture. Yet there may be a way to make retinol work for your skin.
First, let me explain the basics. Retinol is just a fancy name for vitamin A or, to be more accurate, retinol is one of several natural forms of vitamin A. Other forms of vitamin A include retinal and retinyl palmitate. As opposed to many other vitamins, vitamin A does not have much of a direct biological effect. It works via its active metabolite (biochemical derivative) called retinoic acid. Only retinoic acid has direct effect on skin cells and can adjust their metabolism toward a more youthful state. In fact, retinoic acid a.k.a. tretinoin is the active ingredient in Retin A and Renova - some of the best known anti-wrinkle creams . The good news is that skin cells have the "equipment" (specialized enzymes) converting various forms of vitamin A into retinoic acid. Indeed, if sufficient amounts of retinol, retinal or retinyl palmitate are added to the culture of skin cells, the amount of retinoic acid in the cells markedly increases.
Why then many retinol creams are virtually useless? The main reason is that they do not deliver enough retinol in skin cell. The rate of conversion of retinol into retinoic acid is low, so a relatively large amount of retinol needs to be delivered into a cell to produce significant effect. Most creams simply have too little retinol for that. Simply increasing the amount of retinol doesn't quite work for two reasons. Firstly, a cream with too high a concentration of retinol may be almost as irritating as retinoic acid. Secondly, retinol is relatively unstable, so most creams lose potency during storage and use.
What can be done? One possibility is to prepare one's own retinol cream. If retinol concentration is made moderately high (but not too high) it may be enough to produce skin benefits but low enough to avoid skin irritation. Furthermore, if a cream is used up soon after is has been prepared, retinol does not have time to degrade too much.
There are some new technologies to help to increase the amount of retinoic acid in skin cells while limiting skin irritation. Firstly, retinyl palmitate appears to be a better alternative than retinol because it is less irritating and may be used at higher concentrations than retinol. (Just as retinol, retinyl palmitate is converted to retinoic acid inside skin cells.) Another enhancement is to make retinol or retinyl palmitate better able to penetrate the skin. This can be done, for instance, by chemical modification or by encasing retinol (or retinyl palmitate) in special carrier particles, such as micelles or lyposomes. Preliminary research studies indicate that the products based on these new methods are at least somewhat effective (albeit less than retinoic acid) and less irritating.
Despite the advent of more effective retinol products, retinoic acid a.k.a. tretinoin (Retin A, Renova) still offers a better chance of anti-wrinkle effects because its activity does not depend of conversion rates and other variables. However, well-designed retinol products provide a potentially less irritating alternative. A tretinoin user who has developed side-effects, such as skin irritation and/or chronic peeling, may first try to reduce the concentration or frequency of application. If that fails, a well-selected retinol product may be worth a try. (Caution: neither tretinoin or retinol should be used in the event of continuing chronic side-effects.)