Alpha–hydroxy acid (AHA) and Beta–hydroxy acid (BHA) have begun gaining prominence in the field of skincare, particularly in the area of exfoliation. These two acids can be seen in many popular skincare brands, often leading to confusion as to which one is better or if a combination of both should be used for best results.
To make an informed decision and purchase, one must familiarize oneself with how AHA and BHA work on the skin and, also, about the process of chemical exfoliation. So here, we give you an introductory guide on the basics.
Chemical exfoliates perform their job in two ways: they peel away the dead skin cells accumulated on the surface of the skin (as is the case with AHA), or they penetrate the pores of the skin and clear the breakouts (as is with BHA).
Let us now dive into more details about AHAs and BHAs.
What is AHA?
Alpha–hydroxy acid (AHA) is a form of an acid derived from natural substances, like sugarcane, grapes, apples, citrus fruits, and milk. Almonds are also a good source of AHAs in addition to various plant sources.
AHAs work by breaking down the bond that holds the skin cells together, thus paving the way for a better, natural shedding process of the dead skin cells. AHAs, through this act of breaking down, help dissolve the dead skin cells and debris covering the surface of the skin. The molecules in AHAs are made up of water-soluble acids, which make them apt for those with dry and sun-damaged skin.
Glycolic acid, which is the tiniest AHA derived from sugarcane, is the most popular form that is widely used in numerous skincare products. Glycolic acid is excellent for treating wrinkles, fine lines, etc., and is useful in enhancing skin texture and brightness. There are multiple other forms of acids and depending on their type, AHAs can treat anything from wrinkles to hyperpigmentation.
Some of the common types of AHAs are:
This is available in all citrus fruits. However, when it comes to skincare, citric acid is predominantly derived from sugar beets or corn. Citric acid acts as a natural preservative and can treat issues like sun damage, acne, etc.
This is one of the gentlest AHAs and, hence, is suitable for people with sensitive skin. Lactic acid, a derivative of milk, has a natural moisturizing effect on the skin. It is useful to treat pigmentation, dry skin, and even issues like eczema, rosacea, etc.
This almond-derived acid is great for first-time users, for it is very mild and does not penetrate deep into the skin like glycolic acid, lactic acid, or citric acid. This acid is less popular when compared to the other three acids frequently used in various skin care products. Nevertheless, it is beneficial for acne issues considering its antibacterial qualities, and given its low level of penetration into the skin, it is suitable for those with sensitive skin. Mandelic acid can help enhance the texture of the skin and improve pore size.
This is a very mild form of AHA and is derived from apples. Similar to mandelic acid, it has a gentle impact and is not useful as a solo ingredient. Hence, it is typically seen in combination with other stronger AHAs.
This is an AHA derived from grape extracts. It is more than often used to stabilize the pH levels, rather than being used as an exfoliant. Tartaric acid helps alleviate sun damage and acne.
Kojic acid is derived predominantly from mushrooms and other fungi. It helps to brighten and even out the skin tone, in addition to boosting the elastin and collagen production, which helps in minimizing wrinkles and fine lines.
This acid is derived from substances, like rye, barley, and wheat, and, being gluten-free, is especially useful for those with celiac disease. This acid is helpful for people suffering from skin issues, like acne and rosacea, as it works by minimizing redness and swelling by eliminating bacteria.
What is BHA?
Beta–hydroxy acid (BHA) is a type of acid derived from the bark of the willow tree, sweet birch bark, or wintergreen leaves. Its chemical structure is almost similar to that of AHA but differs by the position of one hydroxyl group. Salicylic acid (SA) is the most common and known form of BHA.
BHAs are oil-prone acids and are most suitable for people with oily skin. BHAs have a plethora of antimicrobial and antibacterial properties and are useful for treating redness and soreness of the skin.
Some of the popularly used BHA exfoliants are:
This is the most popular and strong BHA. Salicylic acid is composed of large molecule size and, hence, does not irritate as much as compared to its peer glycolic acid (the strongest AHA). Furthermore, salicylic acid has anti-inflammatory properties, too.
Salix alba or willow bark extract:
Salix alba is a natural BHA that is derived from plants, and its salicin component gets converted into salicylic acid. It is, however, a weaker form of acid and is not that popular for exfoliation.
Betaine salicylate is a BHA that is derived from sugar beets. It is a milder but equally efficient alternative to salicylic acid.
Similarities of AHA and BHA
Both AHAs and BHAs are effective in removing dead skin cells, reducing acne, and softening the skin.
AHAs and BHAs reduce the thickness of the top layer of the skin, which comprises the dead skin cells, thereby enabling the skin to reflect more light. This mechanism gives more brightness to the skin.
The shedding mechanism of AHAs and BHAs allows for an even skin tone and also accelerates the fading of dark spots and marks on the skin.
Both AHAs and BHAs enhance the density of collagen that helps keep the skin firm devoid of wrinkles.
Both these acids have ingredients that attract water and help keep the skin hydrated.
Differences of AHA and BHA
The main difference commonly noted between AHA and BHA is that while AHA concentrates on exfoliating the superficial layer of the skin, BHA penetrates deeper into the skin and the pores.
However, in addition to the above, there are many differences in their mechanism.
- AHAs are water-soluble, while BHAs are oil-soluble. This oil-soluble property of BHA enables it to penetrate deeper into the sebum and pass through the sebaceous follicles.
- BHAs are comparatively less irritating than AHA’s, thanks to their large molecule size and anti-inflammatory properties.
- AHAs do not have any effect on the sebum, while BHAs can bring down the production of sebum, resulting in minimizing the excess oil on the skin.
- BHAs are more effective in cleaning the clogged pores, removing blackheads, and preventing acne. This is because they penetrate deeper into the skin and clear the clogged sebum, minimize the oil-secretion, and loosen the pores. All of this, in turn, makes the removal of blackheads easy.
- BHAs have better photoprotective effects on the skin, while AHAs can, perhaps, make the skin sensitive to the sun, making it more prone to sun-damage.
- BHAs facilitate a smoother physiological process of removing dead skin cells by loosening the bonds of the skin cells. AHAs, on the other hand, act more harshly by encouraging self-destruction of cells through apoptosis (programmed cell death).
What to Choose- AHA or BHA?
When it comes to choosing between the two, it all depends on the issue that one wants to deal with.
- If you have oily skin or acne, then BHAs are the best bet. Where salicylic acid will help reduce acne lesions, BHA reduces the secretion of oil, resulting in less oily skin.
- If you have sensitive or dry skin, then lactic acid AHA would be the right choice as it has hydrating properties. Else, one can go for a mild form of BHA.
- If your goal were to work on the issues concerning just the superficial layer of the skin, like reducing fine lines or wrinkles, evening out the skin tone or mild hyperpigmentation, etc., AHAs would be a better option for you.
If you are unable to decide which one to go for and you do not have any targeted skin issues, then go for a combination of both. A 2009 study revealed that AHAs and BHAs when used together, resulted in a fuller skin. You can use AHAs and BHAs during different times of the day or use BHAs on oil-prone areas of the skin and AHAs on the other regions.
No matter which one you choose, the key is to find the right strength that works well on your skin. One can always start with a milder version and then work upwards.
Choose wisely and say hello to happy skin!
Check out More Content Here