Hyperpigmentation Treatment by Type: Melasma, Post-Acne Marks and Sun Spots

Hyperpigmentation treatment works best when it is matched to the type of mark. Melasma needs tyrosinase inhibitors plus strict photoprotection. Post-acne marks fade faster once the acne itself is under control, with a retinoid added. Sun spots respond most consistently to in-clinic light-based treatment. Every type needs daily broad-spectrum sunscreen.

Which type of hyperpigmentation do you have?

Key Takeaways

For melasma, 0.2% thiamidol matched 4% hydroquinone over 90 days in a randomised trial.

For post-acne marks, topical retinoids gave partial improvement in 85% of participants.

For sun spots, in-clinic light beats topicals in the trial data.

Hydroquinone is prohibited in EU cosmetics, so European shelf options are non-hydroquinone actives.

Daily broad-spectrum sunscreen sits under all three plans.

Melasma is symmetrical brown or grey patching across cheeks, forehead and upper lip that flares with sun, heat and hormones. It relapses, so treatment means long-term control ¹.

Post-inflammatory hyperpigmentation (PIH) is the flat mark left where inflammation happened: a spot, a scratch, an eczema patch. It matches the shape and place of its cause, and once it has developed the course can be long and treatment is often slow ⁷.

Sun spots, or solar lentigines, are the sharply bordered tan-to-brown patches on hands, forearms, chest and face that follow years of cumulative sun exposure ⁸. They rarely fade on their own.

For a full side-by-side of the first two, read melasma vs post-inflammatory hyperpigmentation.

What works for melasma, ranked by trial quality?

Several topicals now match hydroquinone, the long-standing benchmark, in head-to-head trials.

Thiamidol has the cleanest comparison. In an evaluator-blinded randomised trial of 50 women, 0.2% thiamidol twice daily reduced modified MASI scores by 43% (95% CI 35% to 50%) over 90 days, against 33% (23% to 42%) for 4% hydroquinone, with no statistically significant difference between the groups ³. Two participants (8%) on thiamidol developed allergic contact dermatitis ³. Thiamidol is a proprietary molecule, and the review positioning it as a breakthrough is an expert-panel piece rather than an independent synthesis ⁴.

Cysteamine sits close behind. A three-centre double-blind randomised trial found 5% cysteamine with ectoine performed no differently from 4% hydroquinone with ectoine ⁵.

Topical tranexamic acid and azelaic acid come next. Comparative reviews put topical tranexamic acid in the same MASI-improvement range as triple-combination therapy, with fewer adverse effects ², and a randomised split-face trial showed 20% azelaic acid alone significantly reduced pigment scores over 24 weeks ⁶.

What works for post-acne marks?

Treat the acne before you chase the marks. In a systematic review of 48 studies covering 1,356 people with skin of colour, 89% of PIH cases were precipitated by an inflammatory condition ⁷. While inflammation continues, new marks arrive faster than old ones fade.

Topical retinoids were the most frequently studied intervention at 22% of reported treatments, and produced partial improvement in 85% of participants ⁷. That makes them the closest thing PIH has to a first-line topical. Azelaic acid pairs well with them, acting on pigment and inflammation at once.

Laser produced partial improvement in 66% of participants and complete resolution in 26% of one subgroup, though the same review recorded cases where laser made PIH worse ⁷. Chemical peels and hydroquinone had less effective outcomes in the pooled data ⁷. If your skin is deeper than Fitzpatrick III, read our safer treatment hierarchy for skin of colour first.

What works for sun spots?

Sun spots invert the melasma picture. A systematic review of 41 clinical trials covering 3,234 patients found the strongest topical evidence was for mequinol 2% with tretinoin 0.01%, at 52.6% to over 80% efficacy on facial lesions ⁸. That combination is not marketed in Europe, and mequinol is restricted under Annex III of the EU Cosmetics Regulation ⁹.

Light-based treatment ranked higher overall. Intense pulsed light achieved 74.6% to 90% success, picosecond lasers 67.9% to 93.02%, and Q-switched lasers 36.36% to 76.6% ⁸. Cryotherapy reached 37% to 71.4% but caused more severe side effects ⁸.

Pulsed dye and intense pulsed light were least associated with triggering post-inflammatory hyperpigmentation afterwards ⁸. That matters if you pigment easily. These are medical procedures, and they belong with a clinician who treats your skin tone regularly.

Over the counter in Europe there is no sun-spot equivalent of that evidence. A retinoid ⁷, azelaic acid ⁶ and vitamin C ² have data in the other two types and may help gradually here, though none were trialled on sun spots. Daily sunscreen with iron oxides sits under all of it ¹⁰.

Which treatment for which type?

Timelines are ranges. Depth, skin tone and the age of the mark all move them.

Where does hydroquinone stand in the EU?

Hydroquinone is prohibited in cosmetic products sold in the EU. It sits at entry 1339 of Annex II to Regulation (EC) No 1223/2009, the prohibited list, and the only carve-out is Annex III entry 14: 0.02% in artificial nail systems, professional use only ⁹.

Prescription is a separate route. The international Delphi consensus on melasma, built from 38 dermatologists across 11 countries with high agreement set at 75% or more of the panel, still places supervised hydroquinone-based triple combination cream as the gold standard, with azelaic acid, kojic acid and oral tranexamic acid as alternatives ¹. Supervision matters, because prolonged unsupervised use is associated with exogenous ochronosis, a blue-black discolouration that is hard to reverse.

Our comparison of tranexamic acid, hydroquinone and kojic acid goes deeper on the alternatives.

Why is sunscreen the base layer for every type?

Ultraviolet light drives all three types, and visible light adds a second push in melasma and in deeper skin tones. Across nine randomised controlled studies with 188 volunteers testing 30 products, 24 of the 30 significantly reduced visible-light-induced pigmentation, and protection tracked closely with how much pigment each product carried ¹⁰. Those trials were run by a sunscreen manufacturer's research arm.

Iron oxides are the pigment most commonly used in tinted sunscreens, which is why a tinted mineral formula tends to be recommended for melasma over a clear one.

Reapply every two hours of sun exposure. No sunscreen blocks 100% of ultraviolet light, so shade and a hat still do real work.

How long before you see a change?

Eight to twelve weeks is the realistic window for topical treatment of any of the three types. Randomised melasma trials read out at 90 days or later ³⁵, and the azelaic acid trial ran 24 weeks ⁶. If nothing has shifted after 12 consistent weeks, change the plan rather than the product.

Photographs help more than memory here. Same light, same angle, once a week.

Every active named here needs the same handling: patch test on your inner arm first, add one product at a time, and wear sunscreen every morning. Retinoids and acids can sting or flake early on, and a retinoid can purge before it settles. Our routine for hyperpigmentation and dark spots covers AM and PM sequencing.

When should you see a dermatologist?

Any patch that is changing shape, colour or border, or that appeared without an obvious cause, needs a professional look rather than a serum. A few skin cancers present as brown patches.

Book an appointment if 12 weeks of consistent topical treatment has done nothing, if melasma keeps returning, if the pigmentation is affecting how you feel day to day, or if you are considering peels, lasers or a prescription agent. Pooled data across PIH treatments shows a lack of robust efficacy for every modality ⁷, so that choice deserves an in-person examination.

Use This in Your Routine

Stacking pigment actives is where most of these plans go wrong. Skin Bliss is a skincare scanner that checks whether products actually fit your skin, before you buy.

The Skin Bliss Routine Builder lays out your AM and PM steps and runs ingredient-interaction checks, so a tranexamic acid serum, an azelaic acid treatment and a retinoid land on nights that make sense. AI Progress Tracker compares new photos against your first Face Scan, which reads slow change over 12 weeks better than memory does.

Start at getskinbliss.com, and bring your 12-week photo comparison to your next appointment.

FAQ

How do I tell melasma from sun spots?

Symmetry and edges. Melasma spreads in larger patches across both cheeks, the forehead or the upper lip, with irregular borders, and fluctuates with sun, heat and hormones. Sun spots are smaller, sharply bordered and scattered, clustered where sun lands most over years: hands, forearms, chest and face ⁸.

Can you treat more than one type at the same time?

Yes, and many people have two at once. Photoprotection and gentle pigment actives serve every type, so the base is shared. The escalation differs: melasma is managed long-term, post-acne marks need the acne handled first, and sun spots are the likeliest to need an in-clinic procedure ¹⁷⁸.

Is hydroquinone legal in Europe?

Not in cosmetics. Hydroquinone sits at entry 1339 of Annex II to the EU Cosmetics Regulation, the prohibited list, with one carve-out for 0.02% in professional artificial nail systems under Annex III entry 14 ⁹. Dermatologists can still prescribe it, and consensus supports supervised, time-limited courses ¹.

Do these treatments lighten your overall skin tone?

No, and that is not the goal. These actives reduce excess melanin production in the specific patches where it has gone up, which evens out the contrast between a mark and the skin around it. Your baseline tone stays your baseline tone, whatever it is.

Does vitamin C help with hyperpigmentation?

It plays a supporting role. Comparative reviews group ascorbic acid with niacinamide and kojic acid as agents that produce meaningful pigment reduction with a strong safety profile, which suits them to maintenance once a stronger active has done the initial work ².