Not An Allergen.
Not only is this multi-beneficial alpha-hydroxy acid not a published allergen, it is the least irritating of all the AHAs, which is part of what makes it really special.
Mandelic acid’s molecular size is larger that other AHAs, meaning it penetrates the skin less, which is something you want for hypoallergenicity — as a general rule, the smaller the molecule, the deeper the penetration into the skin, the higher the risk of an allergic or irritant reaction. The neat trick is that this larger molecular size does not lessen mandelic acid’s efficacy. For many actives, a tiny molecular size means they can penetrate the skin more readily, but they do so unevenly, increasing the risk of irritation. Mandelic acid remains highly effective even if it penetrates the skin less…making it close to ideal as an active ingredient for sensitive skins.
Mandelic acid is derived from bitter almonds. If you are allergic to almonds as a food, you might still be able to use mandelic acid in your skincare — food and skin allergies do not always correlate. Make sure you work closely with your allergist (prick test) and your dermatologist (patch test) to make sure.
If you have a history of sensitive skin, don’t guess: random trial and error can cause more damage. Ask your dermatologist about a patch test.
On the prevalence of skin allergies, see Skin Allergies Are More Common Than Ever and One In Four Is Allergic to Common Skin Care And Cosmetic Ingredients.
To learn more about the VH-Rating System and hypoallergenicity, click here.
Regularly published reports on the most common allergens by the North American Contact Dermatitis Group and European Surveillance System on Contact Allergies (based on over 28,000 patch test results, combined), plus other studies. Remember, we are all individuals — just because an ingredient is not on the most common allergen lists does not mean you cannot be sensitive to it, or that it will not become an allergen. These references, being based on so many patch test results, are a good basis but it is always best to get a patch test yourself.
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