Exfoliation is an essential step in any skincare routine. The removal of dead skin cells is important for maintaining glowing skin, facilitating other products to work better and keeping issues like dullness and patchiness at bay. And with consumers, craving to be more informed about what they put on their skin, the most popular form of exfoliation is chemical in nature, with alpha-hydroxy acids (AHA) and beta-hydroxy acids (BHA) taking the top spot as go-to ingredients for the same. And while poly-hydroxy acids are also trending right now for being the gentlest exfoliant group out there, the difference between AHAs and BHAs is truly where the conversation gets stuck on all the time.
Both AHAs and BHAs are used for the same purpose - for getting rid of dead skin cells, however, they differ in terms of what they target and the skin type they are best suited for. This is why understanding the difference between the two is necessary for making the right pick for yourself. And no, we are not saying that one is better than the other or that PHAs are the ultimate winners - all three have their unique benefits and results. This Is easier said than done as the science behind them can get a little tricky to understand. But with the help of our in-house skin expert Dr. Sravya C Tipirneni, we are here to help you understand the two - their benefits, what kind of skin types they suit best and tips on how to use them.
- Difference between AHAs vs BHAs
- What is AHAs?
- What is BHAs?
- What is PHAs?
- How to choose the right hydroxy acid for your skin?
- Can you combine hydroxy acids?
- FAQs about AHAs and BHAs
Difference between AHAs vs BHAs
The key difference between AHAs and BHAs is the placement of the hydroxyl group on the carbon chain. This small detail is what makes the difference in the level of penetration and action between the two. While both AHAs and BHAs exfoliate your skin by breaking the bonds that hold the skin cells sticking together, they do so in different intensities. They are also derived from separate sources and target different kinds of issues. As seen above, these two chemical exfoliants can be used on widely different skin types and concerns, some of which we will be discussing in detail below.
What is AHAs?
There are three main types of chemical exfoliants, all of them acids. Some are gentler and less penetrative than others. The main principle of the classification is that the higher the concentration of the acid, the lower is the pH value - hence the greater exfoliation effect it has. The first type is the AHA or alpha-hydroxy acid, this group includes glycolic acid, lactic acid, citric acid, and malic acid. They are derived mostly from fruits, but can also be produced synthetically. They have the ability to dissolve in water, so they work on the surface of the skin to mostly improve its texture. The most commonly used ones are usually glycolic and lactic acid. Dr. Tipirneni recommends the ideal concentration to be between 5% and 10%.
What is BHAs?
BHAs, which stands for beta-hydroxy acids, are oil-soluble acids so they can penetrate your pores a little deeper and work on the skin surface at the same time. Your pores may be clogged with oil and sebum and BHAs can help dissolve this and clean out the skin. They not only benefit the skin texture in the process, but they also unclog the pores and remove the acne-causing sebum. The best examples of BHAs are salicylic acid and tropic acid - with exfoliating and anti-inflammatory effects, these BHAs work wonders for oily and acne-prone skin. They can also help achieve even tone, minimise pores and soften bumpy skin with regular use.
What is PHAs?
Even though we are focusing on just AHAs and BHAs mostly, it is important to know about PHAs as well. The poly-hydroxy acid group is similar in mechanism and action to AHAs. But the only difference is that the poly-hydroxy acid molecules are much larger so they don't penetrate as deeply as the AHAs. Hence, they might be less irritating than the other chemical exfoliants. Since they don't go deep, they have more of a hydrating and antioxidant effect, and are useful for sensitive skin. The best examples of PHAs are gluconolactone and lactobionic acid.
How to choose the right hydroxy acid for your skin?
The ideal type of chemical exfoliation for your skin usually is based on what you're looking for. So, if your goal is to improve your skin tone, patchiness, mild areas of pigmentation, or tanning - AHAs are the most common remedy for that. However, if you have oily, acne-prone skin, widened pores, excessive oil secretion, and oily T-zone and you require a good bit of unclogging and oil reduction, then BHA is your best bet. Lastly, if you have very sensitive skin with rosacea or atopic dermatitis (very reactive skin), then you can go for PHA because it is less strong.
Whichever acid you decide to use, always remember to start off slowly. Try applying it just once a week to see how your skin reacts or doesn't react. Then you can increase the frequency to 2 to 3 times a week, once you are sure there is no irritation or excessive dryness in the skin. You can also decrease the frequency based on how your skin reacts in the beginning. If you don't notice any results even after one or two months, then you can move to a different chemical exfoliant.
Can you combine hydroxy acids?
Dr. Tipirneni revealed, "This is another very common question - can we use more than one type of chemical exfoliant at a time? Of course you can, but you probably don't need to! For an average person with normal skin, one is usually enough to get the job done. Especially if you have very sensitive skin and you are on an anti-ageing regimen already with retinoids, then avoid too many combinations of acids."
If you do feel the need to try a combination, you can combine the poly-hydroxy acids with both AHAs and BHAs but you will lose the benefit of the PHA being more gentle. You have to just be very careful, address your skin concerns, and stick to your skin's needs. You can mix AHAs and BHAs - stick to a gentler AHA such as lactic acid in combination with a BHA and test it on your skin before going full steam ahead. Some tips to try combinations are to do it once a week, use a gentle cleanser and moisturiser, and it so that your skin is hydrated. Even if you're mixing, always use the thinnest texture acid first and then you can apply the next one.
FAQs about AHAs and BHAs
Q. Can you use AHAs and BHAs for ingrown hair?
A. Yes, AHAs and BHAs can help alleviate the issue of ingrown hair in your skin. Lactic acid, an AHA and salicylic acid that is a BHA, can help stop these ingrown hairs. They get rid of the dead skin, soften the skin texture and ‘lift’ the ingrown hair above the surface of the skin so that they don't curl inside and cause an issue.
Q. Can you combine PHAs with salicylic acid?
A. Salicylic acid, which is a BHA, when combined with a PHA (poly-hydroxy acid) may pose the danger of reacting badly. The whole point of using a PHA is to treat your skin with a gentle ingredient and a BHA will defeat that purpose.