Do I need an exfoliating acid if I already use a retinoid?

What would an acid add?

Exfoliating acids dissolve dead cells on the skin's outer layer. Retinoids are vitamin A based ingredients; tretinoin increases production of new skin cells and unclogs pores, while retinol is used for uneven tone, pigmentation and texture. They work differently, but some of their cosmetic goals overlap. An acid is an optional extra, not a missing item on a skincare inventory.123

If your retinoid is addressing your concerns, there is no automatic reason to add an acid. Glycolic acid can help remove dead skin and even out tone, and salicylic acid is an option for acne. Choose an acid for a specific remaining goal, not because your routine needs a larger cast. Persistent acne does not necessarily need more exfoliation: a pharmacist can help choose treatment.45

Give the retinoid time before adding more

For tretinoin specifically, acne sores should improve after 2 to 3 weeks of regular use, although improvement sometimes takes more than 6 weeks. Fine wrinkle improvement can take 3 to 4 months or up to 6 months. Those timings are not a timetable for every retinol product. Adding an acid because results are not immediate risks extra irritation while the retinoid is still getting started.3

How to approach adding an acid

1. 1Check your current treatment first. With tretinoin, do not add other topical medications unless your doctor directs you to do so. Tell your doctor or pharmacist what you plan to add.
2. 2Check your skin before exfoliating. Do not exfoliate sunburned skin or skin with open cuts or wounds. If your retinoid is already causing dryness or peeling, avoid adding exfoliation.
3. 3Choose a gentle approach. Dry, sensitive or acne prone skin needs particular care with exfoliation. Do not substitute a scrub or brush for an acid: mechanical exfoliation can also irritate.
4. 4Set frequency around the product and your skin, rather than assuming daily use. More aggressive exfoliation needs less frequent use. Moisturize immediately afterward.

There is no single acid and retinoid schedule that fits every routine. For retinol, start with a low strength every other night and build up slowly; for prescribed tretinoin, follow your prescription rather than changing its schedule to accommodate an acid. Use retinoids at night. Keep moisturizer in the routine, and use sunscreen and other sun protection during the day.134

When should I skip the acid or get help?

Avoid strong exfoliation if you have darker skin or develop dark marks after irritation; aggressive exfoliation can increase pigmentation. Stop a newly added product if it causes skin irritation and arrange a dermatologist appointment. With tretinoin, report severe or persistent burning, peeling, redness or swelling to your doctor; call immediately for rash, hives or pain at the treated area. Retinoids should not be used during pregnancy.1234

See a GP if acne is not improving with treatment, if spots are deep, painful or causing scars, or if acne is affecting your mental health. Those are reasons to review treatment, not to keep increasing exfoliation.5