We know that the sun can begin to damage the skin through UV radiation which generates reactive oxygen species (ROS) which can lead to photo damage and skin cancers. In addition, UV radiation can lead to the formation of matrix metalloproteinase (MMP) which can degrade elastic and collagen of the skin leading to wrinkling and laxity.
The cosmetic industry has flourished with over the counter products promising results. What are the ingredients that are important and what added benefit do they provide the skin?
A recent article in the Journal of Drugs in Dermatology reviewed the different ingredients. Here is a synopsis.
Retinoid and Vitamin A.
Retinoids, which are a derivative of Vitamin A, have been studied extensively regarding their antioxidant and antiaging properties. Tretinoin is the biologically active form of Vitamin A and one of the few topicals that actually can improve photodamage by minimizing fine lines and wrinkles, mottled pigmentation and correcting skin textural issues. Tretinoin is a prescription and is not available over the counter.
Common OTC retinoids include: retinol, retinaldehyade and retinyl palmitate. These are less potent than tretinoin but can provide some benefit.
Patients that have visited me know that I am a proponent of Tretinoin cream used at night to help minimize photodamage.
Alpha Hydroxy Acids
Alpha Hydroxy Acids are commonly seen in OTC products as glycolic acid, malic acid, lactic acid, citric acid etc. They are the active ingredient used in chemical peels. Physicians can use higher percentage alpha hydroxy acids, but OTC preparations have to be under 10% concentration.
They work by thinning the stratum corneum to help speed up the exfoliating and regenerating process. A study showed that while 25% concentration showed effective results in minimizing photodamage, even the OTC 8% concentration showed benefits after 22 weeks of use.
This is another ingredient that I recommend (serum). It has many important benefits, but it must be kept in air tight, dark (amber) bottle so that it does not oxidize and degrade leaving it ineffective. Not only does it provide photoprotection, it can actually increase collagen type I and III in the skin when used topically.
The biologic form is alpha tocopherol which has beneficial anti oxidant effects. Vitamin E topically helps minimize sunburns, neutralizes free radicals and has a synergistic effect with Vitamin C.
In the next posting, we will discuss more ingredients in over the counter formulations.