Alpha Hydroxy Acids or commonly known as AHAs, has become nothing short of a skincare miracle cure. Used in almost every skincare product from cleansers, to toners, to masks and serums this power house ingredient is worth its weight in gold. 
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Many people have heard of AHA, but actually don’t know what it is.  Alpha Hydroxy Acids are frequently sourced from ingredients that we use in our everyday lives.

Alpha Hydroxy Acids are a class of compounds that are naturally occurring or sometimes synthetic, which act as a chemical exfoliant on the skin.  These acids are derived from both plant and animal sources. Many of these acids are found in foods that we consume everyday, and have now made their way into skincare.

Alpha hydroxy acids can be classed into three different categories: plant based, animal based, and synthetic. There are several AHAs listed below, along with their sources.

• Glycolic Acid: It is the most popular and widely used of all the AHAs. It is derived from sugar cane.  Glycolic acid is able to penetrates the skin deeply, and exfoliates efficaciously due to its small molecular size.  It is favoured  by dermatologists for use in chemical peels, and a common ingredient found in anti-aging products. 
• Lactic Acid: This acid is traditionally derived from sour milk, although most of the products containing lactic acid on the market are synthetically derived and vegan.  Lactic Acid is an intensive yet gentler exfoliator than glycolic acid. Lactic acid hydrates the skin by drawing water from the air and deeper layers of the skin.  
• Mandelic Acid: This lesser known but equally as potent alpha hydroxy acid is derived from bitter almonds.  Mandeleic acid is less irritating and very gentle on the skin compared to other AHAs, making it an ideal choice for sensitive skin types.  Mandelic acid has one of the largest molecules in the AHA family, and penetrates the skin at a slower rate.  It is a great exoliator, and helps to treat hyperpigmentation. 
• Fruit Acids: These are the gentlest of all the AHAs, because of their large molecular structure. Citric (from citrus fruits), malic (from apples), and tartaric (from grapes) are literally ineffective when used on their own.  They are usually paired with other acids like glycolic and lactic when used in skincare formulations.   

Alpha Hydroxy Acids are water soluble and work exclusively on the skin’s surface which make them different from other types of acids (such as BHAs and PHAs). 

The first rule of thumb when using AHAs is to start off slowly.  Alpha hydroxy acids can cause skin irritation, especially with overuse. Glycolic acid can be particularly irritating to the skin, because of small molecular size. So it’s best to integrate them slowly into your skincare routine, and never exceed the recommended usage. Always follow the instructions.  

When starting out, steer away from leave-on products (toners, serums, creams) that are highly potent in AHAs. The key is to remember that less is more. Highly concentrated products do not mean that they are more efficient. In fact, you run the risk of damaging your skin and causing PIH (post inflammatory hyperpigmentation).

AHAs work better on the skin when combined together with other AHAs.  Try to choose products formulated with several different types of AHAs, as opposed to using a product that contains a high percentage of just one. Products that combine different acids at lower strengths tend to be less irritating to the skin, because the acids penetrate at different levels and hydrate at different capacities.  

Remember to always wear sunscreen when using products that contain AHAs.  Alpha Hydroxy Acids increase your skin’s sensitivity to light by  thinning  the top layer of your skin, making it more susceptible to sun damage.  AHAs remove pigment, and also slow down the production of pigment in the skin. Therefore, it’s  important to wear spf.  Without spf protection from the sun, you run the risk of hyperpigmentation and sun damage.  

Do not under any circumstances mix AHAs with retinol, or use on the same day  as retinol. This can cause PIH (post inflammatory hyperpigmentation).  Stay on the side of caution when using AHAs and BHAs together in order to avoid irritation and dryness. The combination of AHA and BHA leave-on products does not work well on all skin types.    

Alpha hydroxy acids works well with any hydrating or moisturising ingredient.  Mixing or layering AHAs with any other type of ingredient would end up disastrous and be overkill.  Remember less is more.