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June 4, 2018

BHA 101: Why This Multitasking Acid May Be the Missing Link in Your Routine

While the powerful AHA usually gets most of the glory, don’t underestimate the hardworking BHA. When it comes to exfoliating, clearing out pores, and fighting inflammation, BHA is your hero, even if you have sensitive skin. Here’s why.




Beta Hydroxy Acids.


The loves of my life.


I honestly don’t know what I did in the world before I discovered BHAs. I mean, I lived in Korea for two years and had no idea they were a thing (more on this in a moment). Chemical exfoliation just wasn’t a thing back in those days. *looks away wistfully*



But now, everyone recognizes the importance of BHAs. It’s one of the acids that is great for all skin types, but if you have oily, acne-prone skin, it may be your new savior. Why? Let’s dig in.


Why BHA?


BHAs (or beta hydroxy acids) are a type of chemical exfoliant that works both inside and outside of the pores to help you achieve clear, smooth, and firm skin. Unlike AHAs, BHAs are oil soluble, so that means that they can penetrate through the oil in your skin and get underneath the surface to really clear out your pores. They are kind of like a chemical vacuum that sucks all of the gunk out of your face. This is why BHAs are so great for whiteheads, acne, and blackheads — they literally get in the pore and work to dissolve all of that nonsense.


With continued use, BHAs can balance out oily skin and reduce the amount of acne, whiteheads, and blackheads that you have. Skinny Legend! We stan!




If you have PIH, or post-inflammatory hyperpigmentation, it can help to fade it, since BHAs (like AHAs) also work on the skin’s surface to gently remove old layers of skin, revealing that pretty brand new skin underneath. So first you’ve vacuumed the gunk out, and then the little BHA street sweeper comes to sweep away the debris. So even if you don’t have oily, acne-prone skin, you can still gain a wealth of benefits from the skin renergation alone. Wins for everyone!


BHAs are also anti-inflammatory and antibacterial. Due to its large molecule size, it isn’t as irritating as other chemical exfoliants can be, which makes it perfect to use for all skin types, even those that are sensitive. It’s like the stable boyfriend who never lets you down, your ride-or-die chick, if you will.


The types of BHA


The most popular and most common BHA ingredient is salicylic acid. Other BHAs you might have seen and heard of are:


  • Betaine salicylate (the one in the COSRX BHA Liquid, aka my holy grail, aka the only skincare product literally everyone on the planet needs)
  • Willow bark extract (the ingredient in the COSRX One Step Pimple Clear Pads)
  • Salicylate
  • Trethocanic acid
  • Sodium salicylate


For brevity, we’re just going to focus on salicylic acid and betaine salicylate. Salicylic acid is in most of your American/Western over-the-counter BHA exfoliants. Some popular ones are the Paula’s Choice BHA Exfoliating Liquid, Stridex acne pads, and The Ordinary 2% Salicylic Acid Solution. These all tend to work in the same way: They get down and dirty to get those pores clean.


BUTTTTTTT in Korea, the use of salicylic acid was pretty heavily regulated until recently. You couldn’t really use it in most over-the-counter cosmetics, which is why the ever-so-popular Paula’s Choice BHA exfoliant is actually formulated with betaine salicylate in Korea, and not salicylic acid. People say that betaine salicylate is gentler than salicylic acid, but YMMV (your mileage may vary). This is where trial and error come into place. You might have to try a few different products to see which one works for you.


How to apply BHA


If you’re looking to incorporate this nectar of the gods into your routine, you should apply it after you’ve washed and toned your face. Since BHAs do not make your skin photosensitive, you can use them in the AM, but I personally prefer to do all of my chemical exfoliation at night. I like to apply it, wait about five minutes, and then move on with the rest of my routine.


skincare mistakes bha


If you are applying both a BHA and an AHA, apply the BHA first, wait about five minutes, then apply the AHA. If you’ve never tried a BHA product before, use it once a day two to three times a week initially, then increase usage as your skin becomes accustomed to the new product.


Do you use a BHA product? Which one? Why do you love it? Let us know in the comments!



Sheryll Donerson got her start as a beauty writer by writing K-beauty reviews for her blog, The Wanderlust Project. These days, she's lifting heavy weights, eating tacos, drinking (too much) coffee and is 1/4 of the beauty podcast, Beauty Beyond Basics (or Triple Bees for short). You can find her on Instagram and Twitter at @sheryllrenata.




I came here as soon as I was done reading AHA 101! Another great article, thank you! It's interesting that the COSRX Natural BHA line irritated my skin, but the BHA Blackhead Power Liquid didn't! I still can't really figure out what the problem is with the COSRX Natural BHA line. The only ingredient I feel like is the problem is the Lactic Acid; maybe it's just that particular ingredient?


I wonder if it's the alcohol in the BHA A-Sol? There's no alcohol in the Blackhead Power Liquid. Alcohol doesn't do well on my skin.


Great post. However, after using Cosrx BHA and AHA for about a week, my skin is peeling off. I wear my sunscreen before going out. Can someone advise me? Am I overdoing? Please help


The CosRX products are on the more mild side of acid products so if you're peeling from them, I would definitely back off on how much you're using them. Slow and steady definitely wins the race. Can you tell a bit about how often you're using them/how you're using them in your routine?


I only used it once a week when I started using the COSRX BHA, and that felt fine to my sensitive skin. However, when I added the AHA to my routine as well I also started with once a week, but my skin already felt kind of overexfoliated after the first try. I added some more soothing steps to my routine after that and let the AHA sit on my skin for 10 instead of 20 minutes, and that seemed to help. Maybe that can help you in your situation, too.
Good luck, and I hope your skin feels better soon! Read more


Thank you leolouie and kimmy. I was putting way more AHA and BHA on my skin. I tried to alternate the products to see which one is peeling my skin off. After 2 weeks of trial, this is my routine now:

1-wash face with Cosrx Good morning cleanser
2-Apply 2 dabs of BHA power liquid on problematic areas
3-wait 5 mins ( I am in super rush in the morning)
4-2-3 pumps AHA ( using it 3 days per week for now)+ wait 5 mins
5-Cosrx honey eye cream
6-Cosrx snail essence
7-Cosrx snail moisturizing cream
8-dab dab dab
9-wear... Read more

Miranda Rico

Sheryll, thank you for introducing "skinny legend" to the Beautytap community 😭Mariah could NEVERRRRR

With that being said, BHA IS THE MOVE!!! I could rent out my pores as storage space for extra cash and have noticed such a difference in their size and texture since using a BHA. The COSRX BHA Liquid is perfection + makes my makeup look incredible for some reason? I don't know why, but I won't question it. BHA 4ever 👏


I have a couple in rotation. One of them is the COSRX BHA Blackhead Power Liquid! 😍


You’ve given me the kick I needed to use my acids regularly. I love them. PC 2% BHA, Mizon AHA & BHA Toner, then Lactic, Mandelic, Glycolic and more AHA. I’m working on a routine instead of slapping them on and hoping magic happens.


I've found BHA's to work best in the morning as well for a lot of my friends that I've had try them. Personally, I actually didn't see much result from BHAs even though I'm combo/oily and prone to congestion; my skin responded better to AHAs and masks to keep things clear and moving. I think it's definitely a process of discovery (like we always say everywhere, YMMV) but the CosRX was definitely the most cosmetically elegant of the BHAs I've tried. Lookin at you Paula, grease city.


I’ve been using Cosrx BHA returning a-sol and I’m loving it ! I have sensitive skin and using it daily hasn’t irritated my skin and what’s more is that it made my skin softer and smoother. And to be honest I didn’t know what to expect from BHAs but now I don’t regret this gentler option to chemical exfoliation.


Yeah that's another thing too; I feel like a lot more people are able to handle BHAs in general/more often just because of how they work. We all love a good exfoliation but slow and steady is definitely the way to go here.


I agree ! My skin seems to handle BHAs better than AHAs.