Alpha-hydroxy acids (AHAs) are among the most widely studied and commonly used natural ingredients in cosmetic skincare products.

What Are Alpha-Hydroxy Acids?
AHAs are a group of naturally occurring acids found in many foods, including fruits. While there are many with various health benefits, a handful are commonly found in cosmetics and especially anti-aging products. They are small, water-soluble molecules that are able to penetrate the outer layer of skin to work their magic.

The main AHAs utilized for their cosmetic benefits include:

Glycolic Acid
Derived from sugar cane, glycolic acid exfoliates and unclogs pores to help retain moisture and thicken skin by stimulating collagen production. Due to its smaller molecular size, it’s able to penetrate deeper into the skin.

Lactic Acid
The gentlest of alpha-hydroxy acids, lactic acid is derived from sour milk and other fermented foods. It’s excellent at attracting moisture to the skin while increasing production of natural ceramides and lightening pigmentation. 

Citric Acid
Taken from lemons and other citrus fruits, citric acid evens the skin tone, targets pigmentation and dark spots, and helps reduce the appearance of fine lines and wrinkles.

Malic Acid
Found in fruits such as apples, malic acid is gentle in treating and preventing acne or fading discoloration of sensitive skin.

Why Are Alpha-Hydroxy Acids So Popular?
AHAs are proven to do two important things for your skin. First, they are exfoliants that gently remove dead skin cells from the surface of your skin. Second, they are humectants that attract water to the skin.

Dead skin cells impede the performance of other useful cosmeceuticals. Instead of physical scrubs that can scratch and irritate your skin, causing redness or inflammation on the surface, AHAs speed up the normal process of skin regeneration by breaking down the “glue” that binds the dead cells to the skin’s outer surface.

Exfoliation provides a clean, uniform surface of new skin which is ideal for the performance of other cosmeceuticals used in your daily routine.

Because AHAs are humectants, they attract moisture to the outer layer of the skin.

They also increase the skin’s natural level of hyaluronic acid, which is another powerful humectant.

Anti-Aging
The combination of exfoliation and moisturizing is rejuvenating to your skin. Regular use of products containing AHAs promote collagen production, reducing fine lines and wrinkles.

As we age, normal collagen production diminishes and causes the skin to become thinner and have more visible lines and wrinkles. The anti-aging effects of AHAs have been demonstrated in rigorous clinical studies that have been published in peer-reviewed journals. 

More Benefits of Alpha-Hydroxy Acids

• Glycolic, lactic, and  citric acids especially, may help lighten skin discolorations. Studies show that AHA-containing formulations reduce melanin production and promote a more even complexion.
  
• AHAs are generally safer than other physical or chemical alternatives for all skin types when used as recommended.
  

Tips for Practicing Safe Skincare with AHAs

• The key in using AHAs is finding the right combination and concentration for your skin.  Introduce AHA products into your routine slowly. During that early period, pay close attention to how your skin responds and adjust your usage accordingly.
  
• You may discover that using products containing AHAs a few times per week is best for your skin. Start slow, with one or two uses per week, and gradually increase use as your skin can tolerate.
  
• Products containing AHAs will increase your skin’s sensitivity to the sun’s UV rays. Be sure to include a daily sunscreen in your skincare routine.

REFERENCES:

The Best Skin of Your Life Starts Here, Paula Begoun, 1st Edition, 2015

Cosmeceuticals, Zoe Diana Draelos, 3rd Edition, Elsevier, 2016

Babilas P, Knie U, Abels C. Cosmetic and dermatologic use of alpha hydroxy acids. J Dtsch Dermatol Ges. 2012;10(7):488-91