The Beauty Alphabet: A is for AHA!

A is for AHA!

AHA as in alpha hydroxy acids, not AHA as in aha!

So what are alpha hydroxy acids?

Alpha hydroxy acids are chemical compounds that consist of a carboxylic acid that is substituted with a hydroxyl group on the adjacent carbon (example structure will be provided soon).

In the cosmetic industry, alpha hydroxy acids are used for its skin rejuvenation, exfoliation, and brightening properties, some may even say anti-aging. They work by promoting cell exfoliation and cell turnover, which makes it a great chemical exfoliant — making it great for those with textured skin, photo-damaged skin, dark spots, more mature skin, or those that just want an alternative to physical exfoliants.

Examples of alpha hydroxy acids include, but not limiting to:

  • Glycolic acid — derived from sugar cane
  • Lactic acid – derived from milk, fruit, vegetables, other plants
  • Malic acid – apples, pears, other fruits/plants, etc.
  • Tartaric acid – derived from grapes, tamarinds, other fruits/plants, etc.
  • Citric acid – derived from citric fruits and juices
  • Mandelic acid – derived from bitter almonds, etc.

If you see the above names on the ingredients list of your cosmetic and personal care products, don’t freak out over the work “acid”. They’re considered acids because they have a pH below neutral 7 and because of their chemical structure as described before.

Functionality of AHAs

As chemical exfoliants, AHAs work on both the epidermal and the dermal levels of the skin. (Refer back to Science of Beauty — The Basics: Science of Skin for a refresher, if needed). When applied, they stimulate the exfoliation of epidermal cells in the stratum corneum, the outer layer of the skin, by interfering with the ionic bonding between these cells. This results in the promotion of cellular renewal, aka new cells from exfoliation.

Not only do AHAs work as chemical exfoliants, they can also adjust the pH of your product during formulation. The most popular being citric acid because of how accessible and cheap it is. Having this in your formula will reduce the pH to become more acidic.

It has also been found that AHAs can improve and restore hydration and plumpness in the skin through an increase in Hyaluronic Acid. Reminder that Hyaluronic Acid is found naturally in the skin and can help in hydration of the skin. (Refer to Science of Beauty: Humectants, Emollients, & Occlusives for a refresher on humectants and hydrators).


Alpha hydroxy acids are class of great multifunctional cosmetic ingredients that can give a number of benefits for skin and hair care (think of exfoliation for your scalp & about how your hair has a lower pH than your skin — Refer to Science of Beauty — The Basics: Science of Hair for a refresher).

They work as chemical exfoliants to generate new cells, helping those with textured skin, photo-damaged skin, more mature skin, etc. It can also improve the look of your skin by promoting hydrators, making your skin look plump and less dull.

In conclusion, AHAs promote softer, smoother skin with faded wrinkles, lightened age spots, and decreased blemishes. If AHAs aren’t included in your skincare or hair care routine, I recommend that you start looking now!

Some of my favorite products with AHAs

Further Reading

Background on Alpha Hydroxy Acids

NCBI – Alpha hydroxy acids modulate stratum corneum barrier function

NCBI – Alpha hydroxy acids for skin rejuvenation

1 thought on “The Beauty Alphabet: A is for AHA!

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

%d bloggers like this:
search previous next tag category expand menu location phone mail time cart zoom edit close