Here we are talking about Alpha Hydroxy Acid (AHA) and Beta Hydroxy Acid (BHA). Naturally occurring acids that have the ability to exfoliate and so smoothen the top layer of the skin, speeding up the skin cycle – or skin cell turnover, which naturally slows down with age. The average life of skin cell cycle in young skin is 30-37 days, which goes to more than 50 in mature skin. This means that dead skin cells accumulate in the top layer of the skin, epidermis, and overstay their welcome making our skin look dull and sad. In young skin, they slough off in a speedy manner with the help of enzymes, and so the overall appearance of the skin is fresh and happy. As this process slows down, it is nice if we give it a push here and there. Acids are fantastic at that, as they act just like enzyme do – by breaking the bonds between dead skin cells on the surface and allowing them to slough off.

Alpha Hydroxy Acid (AHA)


  • Glycolic acid –sugar

  • Lactic acid – sour milk

  • Citric acid – citrus fruit

  • Malic Acid – apples

  • Tartaric – grapes

  • Phytic – rice

Glycolic acid is probably the most famous of the group as it is often considered the most effective one. This is largely due to the small size of its molecule, which makes it better able to penetrate the skin and improve its appearance. Unfortunately, for that same reason, it is the most irritable to the skin, so if you are trying to incorporate it in your routine, you may need to take baby steps until your skin gets used to it.

Lactic acid’s molecule is one of larger size, which makes it gentler, while also having hydrating properties. This may be your better choice if your skin isn’t too happy with glycolic acid.

Beta Hydroxy Acid (BHA)

The champion here is Salicylic Acid – has anti-inflammatory effect and is the best friend of people struggling with acne and rosacea. It is considerably gentler than glycolic acid, and at the same time, because it is lipid-soluble, it penetrates the pores, breaks down the oily material blocking them, and so exfoliates and cleanses them inside out.




  • Smooth the top layer of the skin, without disrupting the barrier’s function

  • May boost collagen production > reduce wrinkles

  • Some acids – salicylic – exfoliate

  • Others – lactic – moisturize

  • Help fade pigmentation

The information on this page is synthesized from
1. Brandt, Fredric, and Patricia Reynoso. Age-Less: the Definitive Guide to Botox, Collagen, Lasers, Peels, and Other Solutions for Flawless Skin. William Morrow, 2002.
2. Michalun, M. Varinia, and Joseph C. Dinardo. Milady Skin Care and Cosmetic Ingredients Dictionary. Milady, 2015.