Beauty & Skincare

What are Chemical Exfoliators? Are They Good? (AHA, BHA & PHA)

You might have known that exfoliating your skin regularly with wash-off scrubs like sugar or tools such as sponges and cleansing brush is good for your skin but have you heard of AHA, BHA and PHA? Chemical exfoliation has been quite a hype nowadays as it promises results. Good results! They are now found in some makeup products too! However, there can be too much of a good thing. In this blog, I will be sharing what are chemical exfoliators, why is it a hype, how much is too much, signs you went overboard with them and tips for beginners in chemical exfoliation.

From left to right: AHA, BHA and PHA
What are chemical exfoliators?

There are quite a few of chemical exfoliators out there which are also known as acids. Here is a list of acids that I often see:

  • Alpha Hydroxy Acid (AHA) includes glycolic acid, lactic acid or mandelic acid which are different in molecular size, works only outer surface of the skin.
  • Beta Hydroxy Acid (BHA) a.k.a salicylic acid is more oil soluble and thus penetrates into the skin to fight against bacteria and clears clogged pores.
  • Polyhydroxy Acid (PHA) works outer layer of the skin and is less irritant than AHA and BHA due to its larger molecule structure. E.g, lactobionic acid.
What do they do? Why the hype?

When you see or hear the word “acids”, you might think of burns and corrosion but this is not the type of acids we are talking here today. Acids a.k.a chemical exfoliators used in skincare are basically similar to physical scrubs which help to remove dead skin cells while your skin generates new skin cells, leaving your face smooth and radiant. These acids are also known for their anti-aging properties as they increase collagen production and reduce fine lines. The difference with physical or mechanical exfoliators is that you do not have to scrub or massage the product onto your skin with chemical exfoliators and you still get complete removal of the dead skin. To have an instant glow and radiant skin, many has added products containing acids into their skincare routine (or maybe not… continue reading to find out more).

My impression and testimony

If you know me well, I have a thing about COSRX products, especially their low-pH morning gel cleanser (contains lactic acid), One Step pimple pad (contains BHA) and BHA Blackhead power liquid (4% BHA). They have saved my acne breakouts and scars 3 years ago by reducing skin inflammation and brightening my skin. No kidding, the scars took some time to fade but for my first impression, the glow was amazing! And recently, they have released a new cream with PHA which has became a favourite for many today.

Ps. NOT all COSRX products contain acids.

My new discovery and the reason I blog about this!

If you have not heard about the dark side of AHA and BHA and you are using them, this is for you. It all starts when I went to an esthetician for a facial treatment. I thought it was just going to be a normal facial wash until we had a chat about chemical exfoliation with acids. As I have sensitive skin, she told me to avoid acids if possible especially stronger ones like BHA or those with high concentration. She did agree that they will make your skin smooth like a baby’s butt but too much is no good as frankly speaking, they are peeling ingredients. Over-exfoliating scrubs off the new layer of skin which acts as a protective barrier, leaving the skin raw and exposed.

My mind was then flooded with doubts and questions. I was thinking about those people who use acids almost every single day or more than 3 times a week. Do they know about this? Can I then use different type of acids together? I recommended them to my friends but I did not counsel on how often they should use. Do they use them everyday?? Why is it such a hype without BIG warnings?? Why didn’t I know about this before??? Aaahhhh…

GIF source

The good thing was my esthetician told me my skin condition is not too bad. The key thing for me right now is hydration. I, then, decided to stop using all products that contain acids and use gentler products instead while allowing my skin barrier to heal and restore.

At this point, you might be thinking that I do not recommend chemical exfoliation and this is NOT true. It truly depends on your skin type and concerns. You just need to use it correctly and not excessively. My esthetician does provide facial treatment using acids but she only recommends her customers to do it only once a year. She also explained that it is the same if you overdo it with physical scrubs. This includes konjac sponges, loofah and cleansing brushes.


I have then researched on how often we should use chemical exfoliators and signs that you are doing it too much.

Signs of Over-exfoliation
جلد چرب
Image source
  • Skin redness and irritation (specifically on the cheeks)
  • Burning sensation or tingling sensation that persists
  • Skin tightness
  • Increased dryness and flakiness (dry, rough patches)
  • Increased oil production
  • Acne

Yes, although chemical exfoliants are claimed to remove your dead skin, unclog your pores and fights against acne while maintaining your moisture barrier, overdoing it can cause your skin to produce more oil to compensate the loss of moisture. As a result, pores will clog and your skin is more prone to acne.

What to do next if you have over-exfoliated?

Based on my experience, these signs do not come at the beginning but only appears when using the products incorrectly for a long period of time. When signs of over-exfoliation started to show and persist, it is recommended to:

  • Check the ingredients on the label if the product contains acid. You will be surprised.
  • Reduce or stop using them.
  • Allow your skin recover while using gentle and hydrating products.
  • Avoid using other active ingredients too like retinoids, papaya enzyme peel and Vitamin C.
  • Go to your esthetician for professional advice.
For beginners, how do you incorporate chemical exfoliant into your skincare routine? How often should you use it? 
Acids formulated in cleansers, toners, essence, creams and even sleeping masks.

Tip 1: Start off with the mild ones such as lactic acid and mandelic acid, especially if you have sensitive skin. Try using it once a week and see how it goes. You can increase up to two to three times a week if your skin tolerates but for sensitive skin, I do think once a week or twice a month is enough. For normal skin or acne-prone skin, you can switch to stronger ones like BHA (1-2% for a start, 4% max.) and once a week is enough.

Tip 2: I recommend to use ONE acid at a time. Check all of your skincare products if they contain chemical exfoliant and what is the concentration.  Also, avoid using them with other active ingredients like retinoids, enzyme peels and Vitamin C if your skin cannot tolerate.

Tip 3: Check with your esthetician if chemical exfoliants are suitable for your skin type or if your skin needs acids even if the product claimed to be suitable for sensitive skin.

Tip 4: Use sunscreen as your skin is more prone to sun damage after using acids. Well, even if you’re not using these products, a daily sunscreen is a must too.

Tip 5: Moisturise your face with oil or creams after chemical exfoliation.

Tip 6: Still not sure? Forget about acids and stick with physical exfoliators and use them up to 3 times a week.

My final thoughts

After all that, once again, I am not saying chemical exfoliators are 100% bad. They treat certain skin concerns so do not throw your products away! It is important to use it correctly while listening to your skin-needs which I emphasise in my blog frequently. After knowing the pros and cons of chemical exfoliators, whether to start or continue using them is totally a personal decision. If you have any questions or concerns, feel free to contact me or leave a comment below. I am not an expert but I will try my best to answer them.

I am also currently doing research on how to restore skin barrier, products for it and how to reintroduce chemical exfoliators if needed. If you would like to know too, leave a comment below and I will be very happy to share in a later post.

Thank you for reading! ❤

Disclaimer: I am not a dermatologist or a qualified cosmetic chemist. The information I provide in this blog is purely based on my experience and knowledge, therefore, I cannot guarantee the information is error-free. I welcome feedback for any misleading information so feel free to contact me or comment below. I hold copyrights use of the images and content of this blog unless credited otherwise. 

5 thoughts on “What are Chemical Exfoliators? Are They Good? (AHA, BHA & PHA)

  1. Thanks for the tips! How often should I use my cleansing brush? I use a good cleansing balm to remove my makeup but it always feels more throughout with the brush! You know what I mean 🙂


    1. Hi Sab! I would suggest to use two to three times a week, assuming that you do not use any other exfoliators along the week. I know some do suggest you can gradually build up the usage from there so I think it also depends on your skin’s sensitivity. I used to use it once a day but I do not think it is necessary when I come to think of it now. Hope this helps! 😉


  2. Very insightful post! Now I know what was happening when I was using acids daily for some time and it became dry and flaky. I have stopped using acids and introducing more moisturizer now, thanks for your advice!!

    Looking forward to the barrier post!

    P.s: I like the tip number 6 😉


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