What is the difference between AHA, BHA, and PHA?

AHA, BHA, and PHA, these 3 ingredients do sound similar, but I assure you that they are very different from each other. While AHA and BHA are the OG chemical exfoliant that we have all heard of, PHA is newer in the market and have just hit the skincare shelves in recent years, all these ingredients are considered as exfoliating acid. The difference is that all 3 of them are targeted to different skin needs. 


AHA, aka Alpha Hydroxyl Acid, are an acid group that includes a lot of different acids, from Lactic acid to Mandelic Acid. This specific group of acid is ideal to treat aging problems, like wrinkles and fine lines, uneven skin tone, hyperpigmentation, and dark spots, as well as dry and rough skin. AHA can shed off the dead skin cells on the epidermis, letting the new fresh skin cells underneath show through, which can help in reducing the appearance of wrinkles and fine lines, fading away from the dark spots, even out the skin tone, and so on, making the skin more youthful. Glycolic acid is one of the most famous AHA, which is known for its effectiveness, it is one of the most potent AHA in the market, it is great for brightening up the skin tone, boosting collagen synthesis, increasing skin renew rate, and more. However, being the most potent, glycolic acid is also one of the most irritating out there, with that being said, if you happen to have sensitive skin types and are experiencing redness and irritations with Glycolic acid, we recommend switching to another AHA alternative, like Lactic acid which can also get the job done without being too irritating.


Also known as Beta Hydroxy Acid, this acid group is best for oil and acne-prone skin. BHA can penetrate deep into the skin, under the epidermis, getting rid of the oil, bacteria that clog the pores, which can the pores to remain clear and clean, not only can it help to prevent acne, blackheads, whiteheads, and other breakouts, it can also help to shrink the size of the pores, making the skin more flawless. Salicylic acid is the most common and popular BHA in the skincare world, it is very known for its ability to clear acne and breakouts. Keep in mind that Salicylic acid also comes in a variety of concentrations, from 0.5% to 2%. If you are using Salicylic acid for the first time, no matter for leave-on treatment or wash-off treatment, start by using 0.5% and use it once per week, this is to let your skin get used to the acid and minimize the risk for getting irritation and redness. Once your skin is used 0.5% of Salicylic acid, you can then increase the concentration and the frequency of application per week. However, if you encounter ant irritation or allergic reaction, wash off the product immediately, and consult with your locate dermatologist if needed.


Lastly, there comes a new acid group, Poly-Hydroxyl Acid. This group of acid is very suitable for sensitive skin types, due it its large molecule size, making it hard to penetrate deep into the skin, it is a gentle and mild chemical exfoliant that can be used by people with eczema or rosacea. The benefits of PHA are very similar to AHA, which we mentioned above. The difference is that PHA is less potent than, and not as effective as AHA, which is great for people who find AHA too strong. Besides having anti-aging properties, like reducing wrinkles, lightening up dark spots and hyperpigmentation, and so on, PHA can also retain and attract water to the skin, making the skin more hydrated, improving sun-damaged skin, and is also proven to be less sensitive to sunlight than AHA. The most common examples of PHA are:

  1. Lactobionic Acid, great for treating spots and pigmentation
  2. Galactose, great for protecting the skin from external stress
  3. Gluconolactone, great for fighting free radicals and keeping the skin hydrated

In general, people with more maturity and sensitivity are more recommended to use PHA, rather than the other 2 types of acid.

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