What is aha serum
Last updated: April 1, 2026
Key Facts
- AHA stands for Alpha Hydroxy Acid, a water-soluble chemical exfoliant derived from natural sources like fruit and milk
- Works by dissolving the bonds between dead skin cells, allowing them to shed naturally without physical scrubbing
- Glycolic acid (from sugarcane) and lactic acid (from milk) are the most commonly used AHAs in skincare
- Improves skin tone, reduces hyperpigmentation, and can minimize the appearance of fine lines with regular use
- Should typically be used 2-3 times per week to avoid irritation, and sun protection is essential as AHAs increase sun sensitivity
What AHA Serum Does
AHA (Alpha Hydroxy Acid) serums are chemical exfoliants that work by dissolving the bonds between dead skin cells on the outermost layer of skin. Unlike physical exfoliants that use scrubbing action, AHAs gently dissolve these bonds through a chemical process, allowing dead skin to naturally shed and reveal fresher, newer skin underneath.
Types of AHAs
The most common AHAs used in skincare products include:
- Glycolic Acid: Derived from sugarcane, it has the smallest molecular size, making it the most effective at penetrating the skin
- Lactic Acid: Derived from milk, it is gentler and more hydrating, making it suitable for sensitive skin
- Mandelic Acid: Derived from almonds, it penetrates slowly and is very gentle for sensitive or darker skin types
- Tartaric Acid: Derived from grapes, typically used in combination with other AHAs
Benefits of AHA Serum
Regular use of AHA serums can provide multiple benefits for skin health and appearance. They improve overall skin texture by removing dead cells that can clog pores and make skin appear dull. AHAs also promote cell turnover, which can reduce the appearance of fine lines and wrinkles over time. Many people notice improved skin brightness and more even tone, particularly in cases of hyperpigmentation or acne scarring. Additionally, AHAs can help improve the penetration of other skincare products by removing the barrier of dead skin.
How to Use AHA Serum Safely
AHA serums should be introduced gradually into a skincare routine. Begin with one application per week, then increase to 2-3 times weekly as skin builds tolerance. Always apply to clean, dry skin and follow with a moisturizer. Sun protection is critical when using AHAs, as they increase skin sensitivity to UV rays. Use a broad-spectrum SPF 30 or higher daily. Avoid combining AHAs with other active ingredients like retinoids or vitamin C initially, and consult a dermatologist if you have sensitive skin or existing conditions.
Related Questions
What is the difference between AHA and BHA?
AHAs (Alpha Hydroxy Acids) are water-soluble and exfoliate the skin's surface, while BHAs (Beta Hydroxy Acids) are oil-soluble and penetrate deeper into pores. AHAs work best for dry or sensitive skin, while BHAs are better for oily and acne-prone skin.
Can I use AHA serum every day?
Most people should not use AHA serum daily, as this can cause irritation and damage the skin barrier. Starting with 2-3 times per week is recommended, and some people with very sensitive skin may only tolerate once weekly application.
What are the side effects of AHA serum?
Common side effects include redness, mild irritation, dryness, and increased sun sensitivity. More serious reactions like severe burning or allergic reactions are rare but possible, especially if used too frequently or with high concentrations.
Sources
- Wikipedia - Alpha Hydroxy Acid CC-BY-SA-4.0
- American Academy of Dermatology proprietary
- NCBI - Chemical Peels CC-BY