What are AHAs? (Alpha Hydroxy Acid)
AHAs stands for Alpha Hydroxy Acids. They are derived from sugar cane or other plant sources and are often called fruit acids. AHAs are chemical exfoliants that help with improving the skin’s complexion and texture, revealing a dewy glow and enhance the natural moisturising factors within our skin.
What are BHAs? (Beta Hydroxy Acids)
BHA stands for Beta Hydroxy Acids. Found in willow tree bark, wintergreen leaves or sweet birch bark. Like AHAs, BHAs are also chemical exfoliants that help improve the skin’s complexion and texture, revealing glowy skin by removing the dead skin cells laying on the skin's surface. BHAs also “detach” the bonds on the surface of the skin that clings onto dead skin.
The main difference between AHAs and BHAs is that BHAs are oil-soluble, making them more appropriate and preferable for those with oily skin and prone to bumps (milia), clogs and enlarged pores. This is because they are able to work on the skin’s surface, as well as penetrating deep into the skin.
Types of AHAs
There are various types of AHAs which are derived from different ingredients and all have different benefits.
- Glycolic Acid = Derived from sugar cane. It is the smallest AHA, allowing them to penetrate deeper into the skin. Recommended for discolouration concerns and contains antimicrobial properties that help prevent breakouts.
- Lactic Acid = Derived from the lactose in milk. Targets concerns of ageing skin, specifically hyperpigmentation.
- Mandelic Acid = Derived from almond extract. Is the largest AHA, thus, suitable for sensitive skin or those trying out AHA for the first time as they do not penetrate too deep into the skin. Beneficial in improving skin texture and minimising pore size.
- Citric Acid = Derived from citrus fruits extract. Its main purpose is to neutralise the skin’s pH and smooth rough patches of skin, and also soothe inflamed skin.
- Malic Acid = Derived from apples. A type of AHA-BHA crossover, all depending on the formulation. Helps to soothe inflamed skin. It is not as effective as the other AHAs but they work well in making other acids more effective, hence, why they are often found in combination with others.
- Tartaric Acid = Derived from grapes. Works to elevate signs of sun damage and after-effects of acne breakouts.
Types of BHAs
- Salicylic acid = Naturally occurs in willow bark, fruits, and vegetables and is the most commonly used and found. Widely known to treat acne and blackheads. Depending on the formulation and concentration, can also help calm redness and inflammation.
- Citric acid = Citric acid is a crossover of both AHA and BHA, it all comes down to the formulation. When formulated as a BHA, it is primarily used to clear excess sebum and dead skin.
- Betaine salicylate = Extracted from sugar beets. It is a gentler alternative to salicylic acid.
- Salix alba/willow bark extract = Extracted from plants. A natural BHA, hence, it is much weaker and the results may not be significant.
What are the similarities?
Stimulates cell turnover and make your skin appear brighter
- As stated above, AHAs and BHAs are chemical exfoliants and they stimulate the shedding of dead skin cells and cell turnover rate as it exfoliates both the outer (the epidermis) and deeper (the dermis) layer which allows your skin to reflect more light, and look more glowy
- Helps to even out rough or bumpy skin texture
Better product absorption
- By getting rid of the layer of dead skin cells it increases product absorption as the dead skin cells will no longer clog the skin, ensuring that you are getting your bucks worth when applying your products.
- Both AHAs and BHAs are also humectants that attract moisture from the surroundings and retain that moisture in the skin, ensuring that it doesn’t seep out
Prevents acne breakouts
- Breakouts occur when your pores are clogged with excess sebum, dead skin cells and bacteria. Chemical exfoliating can help with loosening and cleansing the pores of all the gunk sitting in there.
- Long term use can prevent future breakouts from occurring and help reduce the appearance of enlarged pores.
What are the differences?
BHAs are deal for oily and acne prone skin
- As BHAs are oil-soluble, they work extremely well in reducing excess oil by slowing down sebum production, hence, preventing the buildup of sebum, combined with dead skin cells and bacteria that clog pores which result in breakouts. This also applies to blackheads.
- It also helps to minimise enlarged pores because cleansing the pores of the buildup can make them appear smaller as they are no longer filled with debris.
BHAs have more skin calming properties
- With anti-bacterial and anti-inflammation properties, BHAs are also used to reduce redness, particularly those with rosacea as it is gentle enough to not cause irritants because of its larger molecule size. Whereas, AHA has been more associated with causing irritation and inflammation.
AHAs are better for anti-ageing concerns
- AHAs help with concerns of ageing skin by stimulating collagen synthesis by fibroblasts (responsible for producing collagen in the skin) and decreasing degradation of the existing dermal matrix. By doing so, reduces the appearance of fine lines, wrinkles and the aftermath of UV damage as the skin will be more hydrated and plumper.
AHAs are better for reducing the appearance of hyperpigmentation
- AHAs also evens out discolouration caused by scarring and age-spots (lentigines, melanoma). The new skin cells which are stimulated to renew are more evenly coloured, hence, your skin complexion will be brighter, showing a more youthful appearance
- COSRX AHA 7 Whitehead Power Liquid
- A La Carte 12% Lactic Acid
- The Ordinary Mandelic Acid 10% + HA
- The Ordinary Glycolic Acid 7% Toning Solution
- The Ordinary Lactic Acid 5% + HA 2%
- The Ordinary Lactic Acid 10% + HA 2%
- Pixi Glow Tonic
- Pixi Clarity Tonic
- Benton Aloe BHA Skin Toner
- COSRX Salicylic Acid Daily Gentle Cleanser
- COSRX BHA Blackhead Power Liquid
- CeraVe SA Smoothing Cleanser
- The Ordinary Salicylic Acid 2% Masque
- The INKEY List BHA Exfoliant
For both AHA and BHA
- COSRX AHA BHA Clarifying Treatment Toner
- Some By Mi AHA BHA PHA 30 Day Miracle Acne Clear Foam
- Some By Mi AHA BHA PHA 30 Day Miracle Toner
- Some By Mi AHA BHA PHA 30 Day Miracle Serum
- Some By Mi AHA BHA PHA 30 Day Miracle Cream
- Some By Mi AHA BHA PHA 30 Day Miracle Acne Clear Body Cleanser
- Some By Mi AHA BHA PHA 30 Day Miracle Cleansing Bar
- COSRX AHA BHA Vitamin C Daily Toner
What to note?
It is advised that any products with a 15% or higher AHA concentration should be avoided. The recommended is 10% and less, with less preventing irritation. Those with sensitive skin may come across a burning sensation, itching or dermatitis during or after use. This means that the product’s concentration is too high for your skin. Some products are advised to be used only 2-3 times a week, especially those with sensitive skin.
VERY IMPORTANT: after applying any AHA or BHA product in the day, you must always wear sunscreen as the skin is more vulnerable to UV rays which can actually cause more harm, such as sunburn. However, AHAs increase the skin’s sensitivity more compared to BHAs.
The main take from this is that both AHAs and BHAs offer some level of exfoliation. However we can conclude that BHAs are more suitable for oily, acne prone or sensitive skin while AHAs are more suitable for those with dry skin or those targeting anti-ageing and hyperpigmentation concerns. Is one better than the other? It all depends on your concerns and the reaction of your skin.