AHAs and PHAs for Skin: What are they?

Woman using cotton pad for application

Alpha-hydroxy acids (AHAs) and poly-hydroxy acids (PHAs) have become essential components in many people's daily skincare routines. However, even if you use products containing these skincare acids, you might not realize just what they are and what they do for your skin.

You might see the term "acid" and pause, wondering if it's a good and natural way to care for your skin. Once you learn more about these chemical exfoliating acids1, you'll probably be ready to include them in your regimen as effective skincare exfoliators.

These facial acids, often expressed in their respective acronyms as AHAs and PHAs have similar effects as they may help improve the look of fine lines and wrinkles and age spots.2 It might sound too good to be true, but many skincare consumers swear by these products.

What Are AHAs?

An AHA is an alpha hydroxy acid, such as glycolic acid. AHAs are popular skincare ingredients that come in forms of serums, toners, creams, and concentrated treatments3. They are water-soluble compounds that sometimes occur naturally, but more often, they can be synthetically produced, and extracted from milk or fruit sugars and other plants and animals.3 They have become an essential ingredient in skincare products, especially because of their exfoliation capabilities.

The chemical exfoliation factors in AHAs can help remove dead skin cells to complement skin’s natural turnover process for a smoother complexion3. These dead skill cells are what may make you think your skin looks ‘dull’.

Commonly Used AHAs

There are seven types of AHAs for wrinkles common in skincare 3:

  • Citric acid, derived from citrus fruits
  • Glycolic acid, derived from sugar cane
  • Mandelic acid derived from bitter almonds
  • Lactic acid, derived from lactose or other carbohydrates
  • Malic acid, derived from fruits
  • Tartaric acid, derived from grapes

What Are PHAs?

Polyhydroxy acids, or PHAs, are acid compounds that tackle the look of fine lines and wrinkles and have similar effects as AHAs. Like AHAs, they too are a chemical exfoliant4,6. These skincare agents work much like AHAs, providing exfoliation at the skin's surface, thanks to their large molecular structure. Why is that such a massive benefit? It's because they can't penetrate the skin easily, making them less harsh than other acids, including AHAs, while still effective at exfoliation.4

Commonly Used PHAs

The most common PHAs in skincare include4:

  • Gluconolactone, which acts as an exfoliant and is appropriate for most skin types.
  • Galactose, which has antioxidant and probiotic properties
  • Lactobionic acids, which remove dead skin cells and unclog pores

Common Benefits of AHAs & PHAs for Skin

You will love the multiple benefits of relying on AHAs and PHAs as part of your skincare regimen:6:

  • Exfoliate the skin
  • Help reduce the look of surface lines and wrinkles
  • Unclog pores
  • Help visibly brighten skin

How to Use AHA and PHA?

Both AHA and PHA can be used day or night, but some products are formulated to be used at night so always read and follow the instructions on the label.

One important step to add to your skincare regimen when using AHAs and PHAs is to follow them up with moisturizer and SPF to avoid issues like5:

  • Dryness
  • Irritation
  • Sun sensitivity.
    • AHAs may increase your skin's sensitivity to the sun, which leads to the possibility of sunburn. Any time you plan to go out in the sun after using AHAs, remember to cover those areas with a sunscreen of SPF 30 or higher.

When to Use AHA and PHA?

Both AHA and PHA are great ingredients to use for most skin types, but you should talk to your dermatologist if you worry about any sensitivities.

You should use products containing AHA if you want to exfoliate away dull, dead skin and gently remove discolorations at the surface level of the skin.

A PHA product can help you if you want to reduce the appearance of fine lines and wrinkles and, in some cases, hydrate your skin.6

Which Products Should I Look for That Have AHAs and PHAs?

Neutrogena® has developed products to give you the benefits of AHAs and PHAs in skin-cleansing products such as:

Frequently Asked Questions

  • Q : Can I combine PHAs with vitamin C?
  • A : PHAs and Vitamin C are not recommended to be used together as they may cause irration.7
  • Q : Can AHAs & PHAs be harsh on the skin?
  • A : Some tingling or light peeling may occur when using a high-strength formulation. If you experience sensitivity, reduce the frequency of use until your skin adjusts, then revert to daily use as tolerated. In case of irritation, discontinue use.
    Products containing an Alpha Hydroxy Acid (AHA) may increase your skin’s sensitivity to the sun and particularly the possibility of sunburn. Use a sunscreen, wear protective clothing, an limit sun exposure while using this product and for a week afterwards.
  • Q : Can I use a PHA and AHA at the same time?
  • A : Yes, there are some products that contain both face acids.8

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