Did you know that with alpha-hydroxy acid cosmetics, such as glycolic acid, daily sun protection is recommended?
A family of acids for the skin
Hydroxy acids are a family of substances widely used in cosmetic and dermatological products. They include alpha hydroxy acids such as glycolic acid, beta hydroxy acids such as salicylic acid, polyhydroxy acids and bionic acids.
They are valued for a range of benefits for the skin and appear in creams, serums and peels. Precisely because they are so common, it is important to know how they behave when the skin is exposed to the sun.
What the review covers
The work we are discussing is a review published in 2010. It describes the main classes of hydroxy acids and their use as cosmetic ingredients and in dermatology, for example for photoaging, acne, rosacea and pigmentation disorders.
A large part is devoted to safety, in particular to the effects of long-term use on sun-exposed skin. The authors also discuss the effect of hydroxy acids on melanin production and on tanning, and the role of the formula that contains them.
What emerges
The authors acknowledge that, despite many studies on their cosmetic and clinical effects, the biological mechanisms of hydroxy acids still need to be clarified. They also sum up the few studies available on what happens to sun-exposed skin after these products are applied.
On this point the review reports the recommendation of the CIR, the panel that assesses the safety of cosmetic ingredients. With products based on alpha hydroxy acids, daily use of sun protection should be recommended.
How to read this work
A review offers an overall view and shows where knowledge is solid and where more studies are needed. In this case the authors point out that some mechanisms are still unclear and that studies on sun exposure are few.
The practical message is simple and cautious. If you use products with glycolic acid or other alpha hydroxy acids, daily sun protection is a habit not to neglect. High concentrations and peels should be discussed with a dermatologist, especially if your skin is sensitive or prone to dark spots.
This article is for information only. It does not replace the advice of a doctor or dermatologist, whom you should consult with any question about your skin.