If you’re a skincare enthusiast, you likely know that exfoliating is an essential step to every skincare routine. And you’ve probably noticed that many of the best exfoliating products on the market contain ingredients called AHA (alpha hydroxy acids) and BHA (beta hydroxy acid.)
So what is the difference between AHA vs BHA? And is one better for your skin than the other? This guide will give you the full rundown in terms you’ll actually understand.
What are AHAs and BHAs?
AHAs and BHAs are types of hydroxy acids that can be found in many different skincare products: cleansers, toners, masks, wipes, scrubs, peels, or masks.
They are exfoliating acids that help accomplish the following:
- remove a buildup of dead skin
- prevent clogged pores
- eliminate dry, flaky patches
- create more even skin tone
- fade acne scars and dark spots
- …and more
AHAs and BHAs fall into the “chemical exfoliant” category. They use acids to weaken the lipids (think of them like ‘glue’) that bond the epidermis (the upper layer of the skin), causing dead skin cells to loosen and slough off.
Chemical exfoliation goes deeper into the skin than more surface-level physical exfoliation methods—i.e. dermaplaning, or using a scrub with microbeads. (Be sure to check out this in-depth explanation of why it’s so important to exfoliate!)
AHA vs. BHA: What’s The Difference?
In short: AHAs exfoliate the very top layers of skin, whereas BHAs offer a more in-depth exfoliation and work inside the pores.
AHA (Alpha Hydroxy Acids)
Alpha hydroxy acids (or AHAs) are a group of water-soluble, natural acids that come from sugar cane and other plant sources. You are probably already familiar with some examples:
- lactic acid (found in lactose)
- glycolic acid (from sugar cane)
- mandelic acid (from bitter almonds)
- citric acid (from citrus fruits)
- malic acid (from fruit)
A ton of research has been done on AHAs, but according to the FDA, glycolic and lactic acids seem the most promising. It is for this reason that you’ll likely see glycolic or lactic acids in most over-the-counter exfoliants.
BHA (Beta Hydroxy Acids)
Beta hydroxy acids or BHAs are also naturally-derived acids, but unlike AHAs they are oil-soluble, which allows them to penetrate even deeper into the skin.
As they penetrate beyond the epidermis, they clean and unclog the pores, removing excess oils and dead skin cells.
Unlike AHAs, you may be less familiar with the main BHA exfoliants you’re likely to see in skincare products. Some examples are:
- salicylic acid (while salicylic acid is the most common, from chemists’ perspective it is not a true BHA),
- willow bark extract (which eventually converts to salicylic anyway)
- tropic acid
- trethocanic acid
AHAs are great for a number of skin types and skin concerns.
– They can be used for both normal and dry skin due to their ability to boost the skin’s natural moisturizing factors.
– They can also help with sun-damaged skin and skin-aging (surface fine lines and wrinkles) as they rejuvenate the skin by encouraging cell regeneration.
– They assist in brightening the complexion – when the dead skin cells are removed, the brighter and more radiant new skin is revealed.
– AHAs derived from citric acid can promote this brightening even further, as well as correct discoloration from age spots and scars.
– AHAs promote collagen and encourage blood flow, because of their anti-inflammatory properties. This ensures that the skin cells get the necessary nutrients needed, as well as additional oxygen from the oxygen-rich red blood cells. This helps keep your skin plump and smooth, addressing dull complexions.
– Last but not least, AHAs increases absorption of the rest of your skin care.
Without removing those dead skin cells, your daily moisturizer would sit on top your skin’s surface, without reaching the new skin cells underneath. Since AHAs remove this layer of dead skin cells, it allows your existing moisturizer, serums, and oils to hydrate your new skill cells more effectively.
The result? AHAs help to contribute to fresher and more youthful, refined and radiant skin that is visibly brighter and firmer.
– BHAs have antibacterial, anti-inflammatory and natural skin-calming characteristics, so it can be used by those with sensitive skin, who are prone to redness or even struggling with rosacea. They also tend to be less drying and irritating than AHAs.
It’s also worth noting that AHAs do not have an effect on sebum, but BHAs can slow down sebum production, and therefore reduce excess oil.
AHA vs. BHA: Which is Better?
So now you’re probably wondering… which is better, AHA or BHA?
The truth is, one isn’t better than the other, per se. They do, however, target different issues and different skin types.
AHAs are best for… people who are looking for dry skin relief, anti-aging benefits and or to correct discoloration.
- AHA can be used for both normal and dry skin due to their ability to boost the skin’s natural moisturizing factors.
BHAs are best for… people who want to tackle acne or to reduce sebum.
- BHA is oil-soluble, so it is best suited to normal to oily skin that is susceptible to blemishes, enlarged pores, bumps and clogs and is great for treating blackheads and whiteheads. It is also good for anyone with sensitive skin.
How to Use AHAs
The results of using AHA will depend on the type of acid used and the concentration. Here are some general guidelines which should be followed:
- AHAs can make the skin more sensitive to sunlight so make sure to use a sunscreen if using any AHA product.
- Not all AHAs have the same exfoliating power and this varies depending on the concentration of AHA in the product.
- AHAs at a concentration of 10% or less are likely safe for most when used as directed.
- Anything with a concentration above 10% should only be used by qualified dermatologist, or under their supervision.
If it’s your first time using AHAs, you may (although, equally, you may not) experience minor temporary side effects (like burning, itching or blisters) while your skin becomes accustomed to the product.
It is recommended to always try a patch test first on a small area, before gradually working up to using AHA products every other day, and eventually, every day.
Do not use on skin that is burnt, cut or grazed as you may cause further damage.
How to Use BHAs
The concentration of BHAs is not as high as AHAs; in fact, the concentration of BHAs is typically around 1% to 2% and while AHAs increase your skin’s sensitivity to the sun, BHAs actually have some photoprotective effects.
Although BHAs do not make the skin more vulnerable to sun damage in the same way that AHAs do, it is definitely advised to wear sunscreen.
Like AHAs though, it is suggested to gradually introduce BHAs to your skin. Always try a small test patch and monitor any reactions in the following 48 hours.
If all is well, begin by applying your BHA product every other day, and build up to daily application if your product guidelines allow it.
Importantly, avoid using BHA-containing products on infants and children, and if pregnant or nursing.
General Guidelines for Using AHAs and BHAs
- Apply AHA or BHA products once or twice a day – not more.
- Do not apply either on the eyelid or directly under the eye.
- Apply either AHA or BHA products after washing your face and using a toner, but wait for your toner to dry.
- Allow 4 to 5 minutes for your exfoliant to dry/be absorbed before applying your regular skincare routine of serum, moisturizer, eye cream and sunscreen. The last point becomes a non-negotiable when using either exfoliant, but particularly AHA.
Can You Use AHA and BHA Together?
At this point, you may even be wondering if you can use both AHA and BHA together to get the optimal results. This may be applicable for those with combination skin who want to use BHA on their T-zone and AHA on dryer areas.
Or perhaps you’d like to combat aging yet overall but have oily skin that you’d like to address.
The answer to this question is YES. You can use AHA and BHA together.
If you search online, you’ll find different opinions on this. What’s important though is to find what’s right FOR YOU, and this is just a case of trial and error until you achieve the results you desire. After all, everyone’s skin is different.
Here are some suggestions to get you started:
- Definitely do not apply one on top of the other unless already combined in the one product you are using – both are exfoliants and too much will do more harm than good.
- Start by working your way up to daily use as suggested above.
- Once your skin has become accustomed to both AHA and BHA, try alternating – one in the morning and one in the evening.
- Remember that AHA makes the skin more photosensitive to sun exposure, so you may want to consider using the AHA product at night and the BHA product in the morning. Alternatively, you may want to alternate by day.
- If you use a Vitamin C serum in the morning, it would be best to use your AHA or BHA at night—as combining the acids could potentially irritate skin
Remember to ALWAYS read the instructions for whatever product you decide to go for and follow the recommended instructions.
In terms of frequency, always follow those same instructions. You’ll likely notice a more radiant complexion right away, but the anti-aging and smoothing effect will take a little longer.
After 4 to 6 months of consistent use, your exfoliant would have stimulated the production of collagen and should minimize the appearance of wrinkles.
If you remain unsure about which chemical exfoliant is right for you after reading this article – consult your dermatologist!
Best AHA and BHA Products
AHA and BHA can be found in a large range of skin care products including cleansers, toners and serums. Here are some tips on which one to go for:
Best Cleansers with AHA or BHA
Cleansers are generally the least effective as they have the least contact with the skin and are washed off seconds after applying, not leaving enough time for the exfoliant to be absorbed.
Contact with water also disrupts the pH level of the acid.
That said, those with very sensitive skin might want to give them a try. (Here’s a guide to how to wash your face properly in case you need a refresher!)
– Skinmedica AHA/BHA Exfoliating Cleanser [EDITOR’S PICK]
– Murad AHA/BHA Exfoliating Cleanser
– Alpha Skin Care Refreshing Face Wash With AHA
Looking for a great cleanser that doesn’t have acids? Our favorite is this nourishing, makeup-removing cleansing balm.
Best Toners with AHA or BHA
These should be applied after your regular face wash. Apply a small amount to a cotton pad and wipe across the desired areas that you feel need treating. Allow it to dry and do not wash off.
– Biologique Recherche Lotion P50 [EDITOR’S PICK]
– Pixi by Petra Glow Tonic [EDITOR’S PICK]
– OLEHENRIKSEN Balancing Force Oil Control Toner
– Peter Thomas Roth 8% Glycolic Solutions Toner
Best Leave-on Exfoliants and Serums with AHA / BHA
How often you use leave-on exfoliants will depend on the concentration of the acid. Be sure to always follow the guidance provided on the product you purchase.
Leave-on exfoliants should be applied using a cotton pad after using your regular face wash and toner. Follow with your regular moisturizer and sunscreen after around 4 to 5 minutes. The following products each have rave reviews!
– Dr. Dennis Gross Alpha Beta Exfoliating Peel Pads [EDITOR’S PICK]
– Cosrx BHA Blackhead Power Liquid
– Glossier Solution Exfoliating Skin Perfector
– Paula’s Choice Skin Perfecting 2% BHA Liquid Exfoliant
– Paula’s Choice Skin Perfecting AHA Gel Exfoliant
– Drunk Elephant TLC Framboos Serum (for a full review, check out our Guide to the Best & Worst Drunk Elephant products)
Best Exfoliating Masks with AHA / BHA
These products are used the same way you would use a traditional wipe-off mask. Leave on for 10-20 minutes (according to instructions) and rinse with lukewarm water to remove. It’s recommended that these are only used once per week due to their strength.
– The Ordinary AHA 30% + BHA 2% Peeling Solution
– Drunk Elephant Sukari Babyfacial (for a full review, check out our Guide to the Best & Worst Drunk Elephant products)
Do you have a favorite AHA/BHA exfoliant that’s not listed here? Drop it in the comments!
Sarah Barthet is a travel, luxury and lifestyle blogger who gave up the world of high finance to follow her passions. She hopes to share her love of luxury travel, fashion, beauty and the odd piece of career advice to fellow successful women who like to enjoy the finer things in life, over on her blog Dukes Avenue.
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KateNovember 14, 2020 at 10:46 pm
How about a follow up with PHA’s and azelaic acid included? And addressing using any of these products with tretinoin (retinoic acid)? Or even non-Rx retinoids? And the now OTC Differin which isn’t technically a retinoid but works much like one. I’d imagine there are people who don’t realize that their retinol products will not play nicely with some of these products. Or with vitamin C. Can you imagine a reader using PC 2% BHA and then her Vitamin C booster? Thinking it’s a great AM routine? Or using DE’s Babyface mask then putting on their night time retinoid? I think we all want the best results as quickly as possible but to stock up and then pile on multiple products with acids as their main ingredients is a recipe for disaster. This is such a tricky subject and I appreciate the time you took to break the information down, there’s just so much more to it. (And I’m sure you already know all of this.) I just hate to think of someone using these products with super high hopes only to end up with burning, red, flaking skin- or worse.
Lindsay SilbermanMay 12, 2021 at 11:03 pm
totally! I’ve sadly made that mistake myself many times (had to learn the hard way that there is a such a thing as too much exfoliation). We do call out in the article that “If you use a Vitamin C serum in the morning, it would be best to use your AHA or BHA at night—as combining the acids could potentially irritate skin”
but agreed that it would be helpful to clarify about not combining AHA/BHAs with retinoids and other actives!