Chemical exfoliants are one of the quickest ways to get smoother, brighter skin, but the labels can be confusing. AHA, BHA, glycolic, lactic, salicylic... what is the difference, and which one should you actually use? Here is a simple breakdown.
What is a chemical exfoliant?
Your skin naturally sheds dead cells, but that process slows down with age, sun damage and dehydration. When dead cells build up, skin can look dull, feel rough and become more prone to congestion.
Chemical exfoliants use gentle acids to loosen the bonds that hold dead skin cells together so they can be shed more easily. Unlike scrubs, they do not rely on friction, so they give a more even result without scratching the skin.
What is an AHA?
AHA stands for alpha hydroxy acid. AHAs are water-soluble, which means they work on the surface of the skin. The two most common are:
- Glycolic acid: the smallest AHA, so it works quickly and effectively. Great for dullness, uneven texture and the look of fine lines.
- Lactic acid: a larger, gentler AHA that also helps the skin hold on to moisture. A good choice for drier or more sensitive skin.
AHAs are best for: dull skin, rough or uneven texture, dryness, uneven-looking skin tone and pigmentation, and the early signs of ageing.
What is a BHA?
BHA stands for beta hydroxy acid. The most common BHA in skincare is salicylic acid. Unlike AHAs, BHAs are oil-soluble, so they can work inside the pore, through the oil, to help clear out the build-up that leads to blackheads and breakouts.
BHAs are best for: oily skin, enlarged-looking pores, blackheads, congestion and breakout-prone skin.
AHA vs BHA at a glance
| AHA | BHA | |
|---|---|---|
| Works | On the skin's surface | On the surface and inside pores |
| Dissolves in | Water | Oil |
| Common types | Glycolic, lactic | Salicylic |
| Best for | Dullness, texture, dryness, uneven tone, fine lines | Oiliness, congestion, blackheads, breakouts |
| Skin types | Normal, dry, combination, mature | Oily, combination, breakout-prone |
Can you use AHA and BHA together?
Yes, but go slowly. Combination skin often benefits from both: for example, a BHA on an oily T-zone and an AHA elsewhere, or alternating them on different nights. Using strong AHAs and BHAs in the same routine every day can be too much for most skin, so start with one and add the other once you know how your skin responds.
How to use a chemical exfoliant safely
- Start slowly. Two to three times a week is plenty to begin with.
- Use at night on clean, dry skin.
- Follow with a hydrating, barrier-supporting serum and moisturiser.
- Wear SPF every day. AHAs can make your skin more sensitive to the sun, which matters a lot in Australia.
- Do not double up with retinol or other strong actives on the same night when you are starting out.
- Listen to your skin. A light tingle is normal. Stinging, burning, tightness or redness that lingers is a sign to pull back. If that happens, our guide on repairing your skin barrier can help.
The ASI AHA Power Exfoliant
Our AHA Power Exfoliant combines glycolic acid and lactic acid to gently remove dead skin cells, smooth texture and reveal a brighter, more even-looking complexion. Calming chamomile helps keep skin comfortable while it works, making it suitable for a wide range of skin types. It is made in our own lab on the Gold Coast.
AHA and BHA FAQs
Which is better for acne-prone skin, AHA or BHA?
BHA is usually the first choice for breakout-prone and oily skin, because it can work inside the pore. AHAs can still help with the look of marks left behind by breakouts and with overall texture.
Which is better for anti-ageing?
AHAs, particularly glycolic acid, are the classic choice for smoothing texture and reducing the look of fine lines.
How often should I exfoliate?
Start with two to three times a week and adjust based on how your skin feels. Some skin types can build up to more often, but more is not always better.
Can I use an exfoliant with vitamin C?
Yes, at different times of day. Use your vitamin C serum in the morning and your exfoliant at night.
Are AHAs safe for sensitive skin?
Lactic acid is generally the gentlest option. Patch test first, start once or twice a week, and always follow with a hydrating serum.