Vitamin A "NON PEEL"
Does retinaldehyde indeed combine the effectiveness of directly acting retinoids with lower potential for skin irritation?
The existing research appears to point in that direction. A German study by Dr. Fluhr and co-workers published in the Journal of Dermatology in 1999 compared irritation potential of retinol, retinaldehyde and retinoic acid and concluded that both retinol and retinaldehyde had a good tolerance profile compared to retinoic acid. A French study by Dr Boisnic and co-workers (also published in the Journal of Dermatology in 1999) looked at the ability of retinaldehyde to reverse skin damage induced by UVA radiation. The researchers concluded that retinaldehyde exhibited "many of the properties of tretinoin [trans-retinoic acid] in its biological and beneficial effects on photoaging" and in particular improved dermal connective tissue by boosting "repair of elastic fibers and reversing collagen alteration induced by UVA exposure".
In addition to skin rejuvenation, there is another application where retinaldehyde may prove comparable or even superior to retinoids - treatment of acne. Retinoids, such as retinoic acid (tretinoin, Retin-A) and adapalene (Differin), have been one of the established acne treatments for decades. Considering that retinaldehyde is converted to retinoic acid in the body, it could conceivably have the same effect on acne as directly acting retinoids. Furthermore, since it is less irritating than retinoids, retinaldehyde may be easier to combine with other potentially irritating acne treatments, such as alpha-hydroxy acids, beta-hydroxy acids or benzoyl peroxide. In fact, two studies have demonstrated the effectiveness of topical 0.1% retinaldehyde combined with 6% glycolic acid in treating acne. Also, there is evidence that retinaldehyde possesses some antimicrobial activity against P. acnes, the bacteria involved in the development of acne. In fact, Dr Pechere an co-workers from Geneva University Hospital, Geneva, Switzerland showed that retinaldehyde is a much stronger antibacterial that either retinol or retinoic acid (published in the journal Dermatology in 2002). It would be useful to conduct studies directly comparing retinaldehyde with retinoic acid and other directly acting retinoids as an acne treatment. The research so far indicates that retinaldehyde holds considerable promise as an acne treatment, especially in combination with other anti-acne agents.
A few commercial skin care products with retinaldehyde are available (albeit not inexpensive) and, as opposed to directly acting retinoid creams, do not require a prescription. If you decide to shop for a topical retinaldehyde product, make sure to check for proper concentration. As we mentioned, the clinically studied retinaldehyde concentrations were typically 0.05% - 0.1%.
The limited available evidence indicates that retinaldehyde may deliver at least some of the skin rejuvenation benefits of directly acting retinoids, such as retinoic acid (tretinoin, Retin A), with less skin irritation and other side effects. Retinaldehyde may also be a useful acne treatment, especially since it appears not only to act via retinoids pathway but also to kill P. acnes bacteria. However, more research is needed to determine whether retinaldehyde is as effective as retinoids for skin rejuvenation and/or acne treatment. If it is, retinaldehyde may become a preferred treatment for most people due to a better side effect profile. If it proves less effective, it could still be a useful alternative for people who cannot tolerate directly acting retinoids. Notably, while retinaldehyde is less irritating than directly acting retinoids, some people are unable to tolerate it either, in which case retinol/retinyl palmitate may be the alternative of choice.