AHAs stands for Alpha-hydroxy acids. These are water soluble acids coming from fruit, milk and sugar cane. Today, they are often created in a lab. They are grouped by their common structure.
Alpha-hydroxy acids can remove outer layer of dead skin cells and reveal the fresh new skin underneath it. They can also help to even the skin tone.
Glycolic acid is the most popular and most researched AHAs. Other AHAs used in cosmetic industry are Lactic, Kojic, Mandelic, Citric, Malic and Tartaric acids.
Some AHA containing products might cause irritation. Starting with products having lower AHA concentration or higher pH can help to avoid it.