By Gemifys
You’ve been consistent with tretinoin for months, your active breakouts have calmed down, and your dermatologist says your skin “looks good” — but those flat, brownish marks left behind by old pimples just won’t seem to budge. It’s one of the most common frustrations in the tretinoin community, and it doesn’t mean the medication isn’t working. It usually means post-inflammatory hyperpigmentation (PIH) fades on a slower timeline than most people expect, and tretinoin alone may not be the fastest tool for that specific job.
Why PIH lingers even when acne is under control
Post-inflammatory hyperpigmentation happens when inflammation from a breakout triggers extra melanin production in the skin. According to the American Academy of Dermatology (AAD), PIH can take anywhere from several months to more than a year to fade on its own, and darker marks or deeper skin tones may take longer. Tretinoin does help over time — it speeds up cell turnover, which can gradually lighten these marks — but because turnover is a slow biological process, visible improvement is often measured in months, not weeks.
What may help alongside tretinoin
Several approaches are commonly discussed by dermatologists as reasonable additions to a tretinoin routine, though individual results vary and any of these should ideally be introduced one at a time to avoid overwhelming the skin barrier:
- Daily broad-spectrum sunscreen. This is widely considered the single most important step — the AAD notes that unprotected UV exposure darkens existing hyperpigmentation and can undo months of progress.
- Azelaic acid. Often used alongside retinoids, azelaic acid has evidence supporting its use for both acne and pigmentation, and is generally considered gentle enough to layer with tretinoin per dermatology sources like the National Library of Medicine.
- Vitamin C or niacinamide serums. Some research suggests these ingredients may help even out tone and support antioxidant defense against further pigment-triggering inflammation, though evidence quality varies by formulation and concentration.
- Chemical peels or other in-office treatments. For persistent or deep-set marks, a dermatologist may suggest peels containing glycolic or salicylic acid as an intermediate step before considering laser.
- Patience and consistency. Because PIH resolves gradually, many people find that marks they thought were “stuck” do continue to fade slowly over an extended period of continued treatment.
About laser treatment
Laser and light-based treatments can be effective for stubborn pigmentation, but they’re generally considered an escalation option rather than a first step, and — as many people find — they’re often not covered by insurance since they’re typically classified as cosmetic. Before pursuing laser, it’s reasonable to ask your dermatologist about trying a longer course of topical treatment first, since PIH does often respond to time plus the right topical combination.
A note on patch testing and irritation
Adding new actives to a tretinoin routine increases the risk of irritation, so introducing one product at a time — and giving your skin a few weeks to adjust before adding another — is generally recommended over combining several new ingredients at once.
This article is for general educational purposes only and is not a substitute for professional dermatological advice. Always consult a board-certified dermatologist before adding new active ingredients to your skincare routine, especially alongside prescription tretinoin.
