Ingredients | January 14, 2026

What is alpha hydroxy acid and what does AHA do for the skin?

By ZO® Skin Health

As a prominent ingredient in many professional-grade skincare products, AHAs play an important role in exfoliating the skin and promoting a youthful, radiant complexion. In this guide, we'll delve into the science behind AHAs, the key benefits, and how to safely incorporate them into your skincare routine.

What is alpha hydroxy acid (AHA)?

Alpha hydroxy acids (AHAs) are a group of water-soluble acids derived from natural sources such as fruits, milk, and sugar cane. The most common AHAs used in skincare include glycolic acid, lactic acid, citric acid, and malic acid. These work by exfoliating the skin, which leads to a smoother, brighter complexion.

AHAs primarily target the surface layers of the skin. They work by loosening the bonds between dead skin cells, allowing them to be discarded naturally. This process results in a more radiant surface and encourages faster skin renewal.

How does AHA work on the skin?

AHAs break down the stratum corneum, the outermost layer of dead skin cells, to reveal more youthful skin beneath.

They are considered chemical exfoliants, as they work on a molecular level to dissolve the bonds that hold dead skin cells together, allowing them to be easily removed.

In addition to exfoliating, AHAs help stimulate the natural cell turnover process. This increased turnover encourages the skin to produce fresh, new cells more quickly and works to promote a more even skin tone.

What does AHA do for skin?

• Improves skin texture – By exfoliating the outermost layers, AHAs smooth rough patches to achieve softer skin. Regular use can provide a polished, rejuvenated look.

• Boosts radiance – AHAs help to reduce dullness and promote a healthy, glowing complexion. This can be beneficial for individuals dealing with sun damage, age spots, and discoloration.

• Reduces fine lines – AHAs can help to address the visible signs of aging. By stimulating collagen production and enhancing cell turnover, AHAs promote firmer, plumper skin over time.

• Helps with discoloration – Dark spots, sun damage, and blemish marks are common skin concerns. AHAs are highly effective at improving uneven skin tone by gently exfoliating the surface and encouraging a more uniform complexion.

• Helps prevent breakouts – When dead skin cells accumulate on the skin's surface, they can clog pores, leading to bblemishes and other skin issues. Exfoliating the skin helps to keep pores smooth and clear. 

Who should use AHAs on their skin?

AHAs can benefit a wide range of skin types, including normal, dry, and combination. If you have oily or blemish-prone skin, AHAs can help by improving skin texture and preventing clogged pores, although those with active breakouts may want to be cautious and consult a dermatologist before use.

If you have sensitive skin, it's important to start slowly with AHA products, as they can be irritating if used too frequently. When used correctly, AHAs can be a great addition to any routine, especially for individuals dealing with uneven pigmentation and early signs of aging. 

How to incorporate AHAs into your skincare routine

1. Start slowly – If you're new to the ingredient, it's important to introduce it into your routine gradually and know when to use AHAs. Start with a product that contains a low concentration and use it every other day or a few times a week to allow your skin to adjust.

2. Use in the evening – Since AHAs can increase the skin's sensitivity to the sun, it's best to apply them in the evening. This reduces the risk of sunburn or discoloration caused by sun exposure.

3. Pair with sunscreen – Always follow up with a broad-spectrum sunscreen during the day to protect your skin from harmful UV rays.

4. Use professional-grade products – We offer a range of AHA products, including the ZO® Exfoliation Accelerator, which is specifically designed to provide effective exfoliation while supporting healthy, radiant skin.

What is the difference between AHA and BHA?

Beta hydroxy acid (BHA) is another popular exfoliant. While both AHAs and BHAs are excellent for promoting a brighter, clearer complexion, your choice between them depends on your skin type and concerns. Here are the main differences:

• Solubility – AHAs are water-soluble and work primarily on the surface of the skin to exfoliate the outer layers. BHAs are oil-soluble, which allows them to penetrate deeper into the pores to exfoliate the buildup of oil, dirt, and debris.

• Targeted concerns – AHAs are ideal for those who want to improve texture and brightness. BHAs, like salicylic acid, are perfect for individuals with oily or blemish-prone skin. They work to unclog pores, reduce redness, and clear up breakouts.

Can you use AHAs and BHAs together?

As their actions are different, you can use both AHAs and BHAs together, though it could be worth using them strategically to avoid potential discomfort. You can do this by either alternating products on different days or using one in the morning and the other in the evening.

Always monitor your skin for any noticeable changes and start with lower concentrations to see how your skin responds.

What are the potential side effects of AHAs?

• Skin sensitivity – Overuse of AHAs can lead to redness and peeling. Always follow product instructions and start with lower concentrations to avoid this.

• Sun sensitivity – Since AHAs can increase sun sensitivity, it's critical to apply sunscreen every day when using these products.

As with any new ingredient, it's advised to conduct a patch test before using AHA products all over your face. Apply a small amount to a discreet area of your skin to ensure there is no adverse reaction.

Is AHA safe during pregnancy?

AHA products are generally considered safe during pregnancy, as long as they're used in moderate concentrations. However, we always recommend consulting with your healthcare provider before introducing any new skincare during pregnancy.

Avoid products with high concentrations of AHA or those used in professional treatments, as they may cause discomfort. Lactic acid is often considered a safer option, as it's typically gentler on the skin.

Achieve radiant skin with AHA products from ZO®

From improving texture and brightness to reducing fine lines and discoloration, AHAs are a powerful tool for achieving smoother, more radiant skin. With consistent use, you can enjoy the many benefits of this science-backed exfoliant. Find out more about AHA products by speaking to a ZO® Authorized Partner or contacting one of our Skin Health Specialists today.