Skincare 101: What Are PHAs?

If you’re a skincare enthusiast, you probably do your best to keep up with the latest trending skincare ingredients and products. While scrolling through beauty forums or flipping through mags, you might have come across polyhydroxy acid (PHA) and wondered yourself, “What is PHA?” While alpha- and beta-hydroxy acids—that’d be AHAs and BHAs—have been a part of the skincare industry for decades, this relatively new ingredient has everyone abuzz. So what does PHA do for skin, and is it worth adding to your skincare routine? You’ve come to the right place for answers.

What Are PHAs?

Polyhydroxy acids are a new generation of AHAs that provide similar benefits as other alpha hydroxy acids, but without causing the skin irritation that is typically associated with AHAs, according to a study from the National Center for Biotechnology Information (NCBI). As such, PHA skin products are ideal for those with sensitive skin, as they provide the exfoliating benefits of AHAs without contributing to redness, dryness, or irritation. They may also help hydrate the skin and support the skin barrier, further minimizing the risk of irritation for those with sensitive skin.

What Are The Benefits of PHAs?

PHA skincare products—which include serums, toners, creams, and targeted treatments— have quickly risen in popularity thanks to their many benefits. Here are a few of the most notable PHA skin benefits.

• Helps moisturize the skin. Per the NCBI, PHAs boast superior moisturizing and humectant properties when compared to AHAs. This means they can help hydrate the skin and lock in moisture to help fend off dryness.
• Improves the look of fine lines and wrinkles. According to a study published in the medical journal Cutis, skincare products that contain PHAs can help minimize the appearance of fine lines and wrinkles.
• Visibly minimizes photoaging. Photoaging is caused by ongoing exposure to damaging ultraviolet (UV) rays. The NCBI found that some PHA-containing products were able to provide significant improvements in photoaging in a range of populations. And one 2004 study demonstrated the ability of gluconolactone, a type of PHA, to help protect against UV radiation. (FYI: PHAs aren’t a replacement for sunscreen, so keep slathering!)
• Helps fight breakouts. If you struggle with acne-prone skin, incorporating a PHA exfoliant into your skincare routine can potentially help. Per the NCBI, using PHAs for skin in combination with retinoic acid (retinol) may be useful for managing adult acne.
• Provides a skin-smoothing effect. AHAs are known for their exfoliating capabilities, and the apple doesn’t fall far from the tree. According to the NCBI, products with PHAs may help improve skin tone and texture while offering a plumping effect when used in a cream with pro-vitamin A.

PHA vs. BHA vs. AHA

PHAs, BHAs, and AHAs are all forms of exfoliating acids, meaning they can visibly retexturize your skin for a smoother, brighter, and clearer look. However, each works in its own way.

BHAs, which include salicylic acid, are often recommended for those with blemish-prone skin, as they can help to unclog pores, per the American Academy of Dermatology (AAD). Meanwhile, AHAs such as glycolic and lactic acid help buff away dead surface skin cells to reveal a smoother, more even-toned complexion. PHAs are a type of AHA that provide a similar effect. However, they have a larger molecular size than AHAs and penetrate less deeply, which makes them well-suited for those with sensitive or easily irritated skin.

How To Use PHAs in Your Skincare Routine

Because PHAs are considered gentle, they’re typically well-suited for all skin types, including sensitive skin. These exfoliating acids are used in a range of products designed to help brighten, smooth, and even the skin. Gentle PHA toners, serums, and moisturizers will all provide gradual results, but if you’re looking for a more rapid improvement in skin texture and tone, we suggest reaching for an at-home peel like the L'Oréal Paris Bright Reveal Dark Spot Exfoliant Peel. It’s formulated with a 25% mixture of AHAs, BHAs, and PHAs and helps visibly improve the appearance of all types of dark spots, including post-acne marks. The gentle formula is suitable for all skin types and tones and provides visible results in as little as one use. Keep in mind that while many PHA products can be used daily, this at-home peel is best used more sparingly—we recommend using it four times per week in the evening.

Frequently Asked Questions

If you have more questions about incorporating PHAs into your existing routine, keep reading—we’re answering a few commonly-asked questions below.

• Do PHAs cause sun sensitivity? Any time you exfoliate, you should use sunscreen to help protect your skin from UV rays. We’re partial to the L’Oréal Paris Bright Reveal Broad Spectrum SPF 50 Daily UV Lotion, which protects, hydrates, and helps prime your skin for makeup.
• Can you use PHAs with retinol? Yes, you can. According to the NCBI, products formulated with PHAs used in combination with retinoids to address adult facial acne were found to be well tolerated. The combination may also help to promote smoother, plumper-looking skin. If you’re unsure of the best way to use retinol and PHAs together, we suggest asking your dermatologist for guidance.
• Can you use PHAs with BHAs? Yes, and you’ll even find products already formulated with both ingredients, like the L'Oreal Paris Bright Reveal Dark Spot Exfoliant Peel.
• Can you use PHAs with moisturizers? Like other acids, PHAs pair brilliantly with other moisturizing ingredients, including hyaluronic acid and glycerin. In fact, the AAD recommends always following exfoliation with moisturization. Just be sure to opt for a gentle moisturizer to avoid irritating or over-exfoliating your skin.
• How often should you use PHAs? How often you use your polyhydroxy acid serum, toner, cream, or treatment depends on the product formulation. Refer to the on-label directions for best results. Anytime you introduce a new product or ingredient to your skin, it’s a good idea to perform a patch test first. This helps you determine whether your skin will tolerate the product. Simply apply a small amount in a discreet spot—like under your chin or on the back of your neck, and observe for a day or two. If you don’t notice any irritation, you should be safe to use it. Always consult with a dermatologist if you’re unsure whether a product is right for you.

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