Paula's Choice AHA toner: what to choose and how to use it

What does an AHA toner do?

AHA means alpha hydroxy acid. Glycolic acid and lactic acid are common examples used in cosmetics. AHAs loosen the substances holding dead surface cells together, helping those cells shed and revealing skin with a more even colour and texture. Regular use can improve the appearance of fine lines and brown marks associated with sun damage. These are benefits of AHA skincare generally, not a reason to assume every bottle has the same strength or effect.1

A toner is usually a watery product applied after cleansing and before moisturising. Some hydrate; others contain acids that exfoliate. An exfoliating toner and a hydrating toner do different jobs, despite sharing the same job title. Choose by the ingredients and purpose rather than the category printed on the front.3

Should you choose AHA or BHA?

Dry skin does not automatically mean an acid is the right choice. Exfoliation can worsen dryness, and a mild chemical exfoliant is generally a better starting point than an aggressive scrub for dry or sensitive skin. If irritation is already the main problem, decide whether exfoliation is beneficial before choosing a stronger product. More aggressive exfoliation calls for less frequent use, not a more determined application.5

How do you use an AHA toner?

Use the exact product's label for its amount and whether to rinse. A leave on AHA product and a rinse off peel are different treatments. Professional glycolic peels use much higher concentrations than typical home skincare; their application times and strengths are not a template for a toner.14

1. 1Test a small amount on one area before applying glycolic acid across your face.
2. 2Cleanse, then gently apply the toner. For a leave on toner, do not wash it off.
3. 3Start glycolic acid once or twice a week at night. Increase frequency only if your skin tolerates it.
4. 4Apply moisturiser after exfoliating to help limit dryness.
5. 5During the day, use broad spectrum sunscreen with SPF 30 or higher and reapply every two hours.

For the UK Skin Perfecting 2% BHA liquid specifically, Paula's Choice tells you to apply it to clean skin using hands or a cotton pad, leave it on, and begin every other day. Its directions allow up to twice daily after assessing your skin's response. Follow with treatments, then moisturiser, and sunscreen for daytime use. That upper limit is not a daily target.2

Can you combine AHA with BHA, retinol or vitamin C?

When introducing glycolic acid, avoid adding other exfoliating acids, retinol or vitamin C serums at the same time. Reducing active ingredients makes irritation easier to trace. Once an AHA is tolerated, alternating it with retinoid creams or vitamin C is an option. Prescription retinoids, retinol and benzoyl peroxide can already make skin sensitive or cause peeling; adding exfoliation can worsen dryness or breakouts.145

Count exfoliating masks as exfoliation too. Adding a mask containing similar acids to an existing acid routine can trigger dryness and irritation, especially on sensitive skin. Check the mask's ingredients rather than treating a weekly mask as separate from your routine. If a mask causes itching, burning or stinging, wash it off immediately; seek a dermatologist's help if your skin feels worse afterward.6

How long does AHA take to work?

Expect gradual improvement rather than a peel like result from a home toner. Glycolic acid skincare can take several months of consistent use to make brightness or pigmentation visibly better. Fine line improvement involves more than removing surface cells: with higher concentrations and long term use, AHAs can also affect collagen and elastin, the proteins that help give skin structure and stretch.14

Acid toners can smooth texture and make pores look smaller, but pore size is largely genetic. Judge progress by the concern you wanted to improve, such as rough texture or uneven colour, rather than expecting pores to disappear.3

Who should be careful with an AHA toner?

Be cautious with glycolic acid if you have sensitive or dry skin, rosacea, eczema, an active infection or skin that is not healing. Low concentration glycolic acid is generally considered safe during pregnancy, but check with your healthcare provider before use if pregnant or breastfeeding.4

Do not exfoliate sunburned skin or areas with open cuts or wounds. Stop exfoliating if your skin becomes red and irritated. Avoid strong exfoliation if you have darker skin or tend to develop dark marks after acne, burns or insect bites, because aggressive exfoliation can increase pigmentation. A dermatologist can help decide whether exfoliation suits your skin, particularly if you are unsure how to fit it around existing treatment.5

What is Paula's Choice AHA BHA toner?

AHA and BHA name different acid families, not one interchangeable ingredient. Paula's Choice allows alternating or combining AHA and BHA to address different concerns, but introducing acids separately is the more cautious starting approach. If you have a salicylate allergy, check with your doctor before using the BHA liquid.2