AHA is a category, not one ingredient strength. Glycolic, lactic and mandelic acid products can differ substantially in concentration, pH, format and frequency, so product instructions matter more than copying another routine.
What are AHA acids?
Alpha hydroxy acids are chemical exfoliants that loosen bonds between surface skin cells. They are commonly used in leave-on toners, serums, masks and rinse-off peels designed to improve the appearance of texture and radiance.
Common types of AHA
| AHA | Typical use in cosmetics | What to know |
|---|---|---|
| Glycolic acid | Surface exfoliation and smoother-looking texture. | Small molecular size can make some formulas feel stronger. |
| Lactic acid | Exfoliation with humectant properties. | Often chosen by people wanting a gentler-feeling AHA option. |
| Mandelic acid | Surface exfoliation. | Larger molecule and often used in gentler-feeling formulations. |
How to start using AHA
- Follow the product's frequency and contact-time instructions.
- Start less frequently if you are new to chemical exfoliation.
- Use moisturiser if the skin becomes dry.
- Stop for a few days if irritation develops.
- Do not assume stronger or more frequent use gives faster results.
Can you combine AHA with retinol or other acids?
Some experienced routines combine them, but using several exfoliating or irritating active products together can increase dryness and stinging. Introduce one major active at a time and consider alternating nights.
Read our Retinol Guide before combining strong routines.
AHA and sun protection
Exfoliating acids can make skin more sensitive to irritation and sun exposure. Use daytime sunscreen and avoid deliberately increasing sun exposure while using exfoliating routines.
See our Face Sunscreen Guide.
Can sensitive skin use AHA?
Possibly, but start with a mild formula and low frequency. If skin is inflamed, damaged or already reacting to retinol, benzoyl peroxide or other active products, exfoliation may need to wait.
FAQ
Is glycolic acid an AHA?
Yes. Glycolic acid is one of the best-known alpha hydroxy acids.
Can I use AHA every day?
Some products are designed for frequent use, but tolerance varies. Follow the exact formula's instructions and reduce use if irritation develops.
Should I moisturise after AHA?
Usually yes if your skin feels dry or tight. A simple moisturiser can support comfort.
For the wider routine, skin-type and ingredient map, see our Complete Skincare Guide.
