Mandelic acid or salicylic acid for acne prone skin?

What is the difference?

Blackheads and whiteheads form when oil and dead skin cells plug a pore. Mandelic acid belongs to the water soluble exfoliating acids, which loosen the bonds between surface skin cells. Salicylic acid is a beta hydroxy acid, or BHA: an oil soluble exfoliant that reaches deeper into pores and helps remove the oil contributing to blockages. Salicylic acid also reduces swelling and redness and helps clear and prevent pimples.1234

Pick the acid for the problem you want to treat, not for the bottle's ability to sound like a chemistry degree. For mild acne, salicylic acid washes are one treatment option. If you have numerous inflamed spots or deep, painful lumps, the decision needs to extend beyond which exfoliating acid to buy.256

How should you start?

1. 1Read the product directions first. A wash, a product left on the skin and a peel need different application instructions. There is no single strength or morning versus evening schedule for every formula.
2. 2Test before wider use. For salicylic acid, apply a small amount to one or two small affected areas for 3 days. For a home peel, test a small amount on the jawline or behind the ear and wait a day.
3. 3Start salicylic acid less often if needed, then increase only as your skin adjusts and within the label's directions. Reduce frequency if dryness or irritation develops.
4. 4Keep the supporting routine gentle. Use a mild cleanser, avoid scrubbing, moisturize morning and night, and wear sunscreen with SPF 30 or higher every day.

What if your skin is sensitive or you use acne medication?

Sensitive or dry skin needs particular care with home peels. Higher strengths and formulas containing more exfoliating ingredients can make a peel more aggressive. Using retinol, tretinoin or adapalene beforehand can also make a peel penetrate more deeply. Do not assume that switching to mandelic acid removes the need to check the formula and test it first.2

Do not add salicylic acid to skin already treated with benzoyl peroxide, tretinoin or other topical medicines unless your doctor directs you to. Avoid abrasive cleansers and products containing alcohol on the same treated skin. A simpler routine is easier to keep using, even if it gives the bathroom shelf less to talk about.14

How long should you give it?

Acne treatment usually needs at least 6 to 8 weeks before fewer breakouts become noticeable. Blackheads and whiteheads can take longer: improvement in comedonal acne, meaning acne dominated by plugged pores, can start around 8 to 12 weeks, while clearing can take months. These are general acne treatment timelines, not a separate timetable for mandelic acid. Persistent clogged pores can need another treatment, such as a retinoid, rather than more exfoliation.35

When should you stop or get help?

Do not apply salicylic acid to broken or irritated skin. Seek medical advice for severe or persistent irritation or stinging. Stop using it and get immediate medical help for hives, throat tightness, breathing difficulty, faintness or facial swelling. If you are pregnant, planning pregnancy or breastfeeding, discuss salicylic acid with your clinician before use.4

See a clinician sooner for cysts, worsening acne, scarring or acne causing emotional distress. If careful use of nonprescription treatment has not helped after several months, ask about a different treatment plan instead of increasing acid strength.7