Alpha hydroxy acids (AHAs) and Beta Hydroxy Acids (BHAs) are the superstar exfoliants in the beauty industry. They are a class of chemical compounds with a powerful ability to exfoliate the skin, slough away dead skin cells and expose a new, smoother, and more even complexion.
But, remember, one acid group is not better than the other.
They’re both equally powerful in tackling down different issues. It’s up to us to learn how exactly do they work on the skin, what are the differences between them, and how to use them most effectively for our skin type.
So, let’s find out.
The beauty industry uses chemicals like AHAs and BHAs to create exfoliating products that guarantee a glowing complexion, fewer fine lines, and a more even skin tone. This is because the active ingredients in hydroxy acids have small molecules, excellent bioavailability, and are able to penetrate the skin to get to living cells.
In this context, the formulation of the product is more important than concentration alone. The bioavailability of AHAs and BHAs is what determines their effectiveness. For example, a really concentrated AHA or BHA product with neutral pH balance would be ineffective because the bioavailability is extremely small in that case. But if the product has low pH, even small concentrations can be effective because a significant amount of the acid is available. The freer the acid, the more effective it can be in exfoliating your skin.
Typical scrubs are great removing the dead skin cells on the surface of your skin, but for them to be able to work on more complex issues, such as wrinkles and acne, the products must be able to penetrate through the epidermis and get to the living cells in the dermis. And this is what makes hydroxy acids great liquid exfoliants.
There are three types of hydroxy acids used in cosmetics: AHAs, BHAs, and PHAs.
Alpha hydroxy acids or AHAs are naturally occurring chemical compounds, although they can be derived synthetically as well. AHas are really well known in the beauty industry, and if I ask you to name one acid used in skincare, it’s most likely you would name one that belongs in the AHA group. You can find AHAs in cleansers, toners, moisturizers, masks, and even professional peels used for the reduction of wrinkles, fine lines, brown spots, discoloration, or in other words, used for the improvement of the overall look and feel of the skin.
The superstar in this group, with the highest bioavailability (the ability to penetrate the skin and work on deeper layers), is the glycolic acid found in sugar cane.
Not much behind, in terms of popularity, is the lactic acid found in sour milk, which doesn’t work as deep as glycolic acid, but that’s why it’s much gentler and recommended for people with more sensitive skin.
Other AHAs famously used by the cosmetic industry are:
Beta hydroxy acids or BHAs are organic compounds - close cousins of AHAs, and they’re also used in the cosmetic industry. If you have oily skin or are facing frequent acne outbreaks then BHAs might be the right choice for you - because they just love oil and will go straight to the sebaceous glands to do their magic.
The most famous, and to be fair the only acid in this group used in cosmetics is the salicylic acid, which can be found in aspirin.
You can find it in over-the-counter products, creams, toners, masks, and of course professional peels. BHA is more specifically advertised for acne problems because it's stronger on the skin, but it can also be used for wrinkles and scars.
So, is the difference between AHAs and BHAs just about their strength? Well, not quite, and we’ll cover this in great detail right away.
Before we dive in and explore the old and well known AHAs and BHAs, we thought we’d say a few words about the new kid on the block.
We can argue which acid is gentler, but at the end of the day, both AHA and BHA cause irritation to someone with extremely sensitive skin. And, this is where PHAs come into play.
Polyhydroxy acids or PHAs have larger molecules than AHAs and BHAs which lessens their bioavailability and limits them to the most superficial layer of skin, the epidermis. They are great for exfoliating dead skin cells and debris, although might not be effective against wrinkles and scars.
Still, PHAs are so great for sensitive skin that they can even be used by people with rosacea or eczema. If you belong to this group, you should look for products containing gluconolactone and lactobionic acid.
Now that you have a better understanding of hydroxy acids, let’s see how exactly do they affect the skin, and how to choose the right acid for your skin.
If you are someone who is only looking for a good-quality exfoliant and want to clear your skin from impurities, then the truth is, you can go for both AHAs and BHAs. Unless you have particularly sensitive skin, you can experiment with glycolic and salicylic acid to see which one will suit you better.
Both AHA and BHA are great agents for deep exfoliation. They can dissolve dead skin cells and debris, clear and unclog pores, decrease the appearance of large pores, reduce superficial fine lines, even out your skin tone and decrease inflammation.
This one is a major side effect both AHA and BHA share.. You should always be extremely protective of your skin when it comes to potential sun damage, but when you’re using hydroxy acids, it’s even more important. The acids make the skin photosensitive and prone to sunburns.
No matter which AHA or BHA you choose, always apply sunscreen with SPF above 30 in the morning or before going out to prevent burns, age spots, and increased skin cancer risks.
BHAs have smaller molecules than AHAs which means they have greater bioavailability and can penetrate the skin more effectively reaching deeper layers and living cells. On the downside, greater bioavailability also means that the acid has a stronger effect and it irritates the skin more.
To make things more simple, we can say that if you really want to hit hard - go for salicylic acid or glycolic acid (depending on your skin issues which are discussed in the next paragraph). But, if you have more sensitive skin go for lactic acid or even consider PHAs as an option.
Another thing you should always check before deciding to buy is the product’s concentration and pH value which are the key determinants of strength and bioavailability. So, even though salicylic and glycolic acids are stronger, if the product contains them in really small concentrations and has a neutral pH value it’s most likely that the product will be gentle and less effective than a lactic acid product with with a lower pH value.
One of the main differences between AHAs and BHA are their water vs oil-based solubility.
AHAs love water molecules. When these acids penetrate the skin they lose the bonds that hold together the top layers of dead skin cells and work on the living cells of the dermis by stimulating collagen, promoting cell turnover and battle discoloration. By promoting collagen production and cell turnover the acids fight off wrinkles and make the skin appear tighter and younger. And, by making space for new more evenly pigmented cells, AHAs fight brown spots and discoloration.
On the other hand, BHA (salicylic acid) is an oil-soluble acid. What this means is that BHA dissolves sebum and unclogs the pores. When it penetrates the skin it goes straight to the oil-glands and reduces the excess oil production. This is why salicylic acid is especially effective against pimples and frequent acne breakouts.
Having in mind the above-mentioned differential characteristics of AHAs and BHAs we know and can give advice on what is best to use and for what.
If your main concerns are symptoms of aging, like wrinkles or brown spots and uneven skin tone, you should go for an AHA product. If your wrinkles are deeper, or your discoloration is more enhanced your best choice is glycolic acid. But, if you have sensitive skin, try out lactic acid first and see how it goes. Also, AHAs and especially lactic acid work great for dry skin as it will help to lock moisture into your skin.
On the other hand, if your main problem is acne breakouts, go for BHAs and its one representative - salicylic acid.
The salicylic acid naturally occurs in the white willow tree and contains anti-inflammatory properties, also great for treating blemishes and zits. This acid works its way deep into the pores and dissolves the sebum, which in turn clears the skin and improves the condition of the pores.
Additionally, you can use AHAs and BHAs in combination with other products as well, because they are both very effective in boosting the effectiveness of other products by allowing them to penetrate deeper into the skin.
We’ve already covered the main determinants of what makes a product effective and by now you might be getting the idea of what would be good for your skin type and condition.
But, to summarize everything nicely, here’s what you should be looking at when making a decision:
People usually focus on questions like “Should I use AHAs or BHAs?”, and we’ve just got you covered on how to choose the right type of hydroxy acid for your skin, but now let's examine the possibility of using AHAs and BHAs together.
Would that be too much for the skin? Not necessarily - if you know how to introduce them to your skin, and we’ll talk about this shortly.
The thing is, AHAs and BHA have separate benefits. AHAs are more about clearing out dead skin cells and cell turnover, while BHAs are more about pore cleaning and inflammation reduction. This means you won’t have a problem to use both and maximize the chances of a successful result.
If it’s your first time using hydroxy acids for the skin, it’s best to choose a product with an acid that is gentler on the skin. The safest way to start is with PHAs, but if you want something stronger and effective, the best starter acid is lactic acid.
Apply a small amount of the product on a small area of the neck fist, and wait for 24 hours to see how your skin is going to react. If everything looks good and you don’t develop an allergic reaction, redness, a rash, or itchiness, you are good to go.
Once a week would be a good start so that you leave your skin some time to adjust to the new pH balance and the changes that the product will be triggering.
The liquid exfoliators will do their job, but in the process, they will leave your skin sensitive and vulnerable to external pollutants and sun damage. This is why it’s important to nourish your skin with some hydrating and moisturizing products, as well as, regularly use sunscreen.
We’ve just mentioned that you should start off by applying once a week and leave some time for the skin to adjust to the changes.
After a couple of weeks, or maybe a month or two you can start using the product three to four times a week.
When you start to feel this frequency of application as a routine and you find it comfortable for the skin, you can increase it to almost every day. Make sure your skin is reacting well to the increases in your application.
The truth is, there are no rules that can give you the perfect recipe, but these are the suggestions that can safely guide you on your journey to effectively use the hydroxy acids for your everyday skin concerns.
The hydroxy acids are powerful liquid exfoliants, having many advantages over typical physical exfoliants. While other scrubs can scatter away dead skin cells, AHAs and BHAs have the ability to actually penetrate the epidermis and work their magic on the living cells inside the dermis.
The beauty industry uses three types of hydroxy acids: AHAs, BHAs, and PHAs.
AHAs are best for diminishing the look of lines and wrinkles, evening out the skin tone, and improving the overall appearance of the skin.
BHAs are best for oily skin and frequent acne breakouts.
PHAs, which are relatively new and not as famous, are pretty mild and a good alternative for people with extremely sensitive skin.
Both AHAs and BHAs share some benefits and both make the skin sensitive to sun exposure.
But, the key differences between these powerful acids are seen in their bioavailability, strength, solubility and their use. So, to be able to choose the best product for your skin type you should take into consideration the pH value, the concentration, the acid group and the specific acid used in the product formulation.
Make sure you start slowly and gradually increase the use of hydroxy acid products.
With time results will come.