Azelaic Acid or Hydroquinone?Four Melasma Trial Checks

Before replacing a prescribed melasma cream with an azelaic acid product, compare the concentration, preparation and intended outcome. A lower pigmentation score does not tell you how long improvement lasts after treatment ends.

Who was actually studied?

The 2011 Iranian trial enrolled 30 women with epidermal melasma. One azelaic acid user stopped after two weeks; 29 completed. It was open-label, with evaluators masked to treatment.¹

Participants applied 20% azelaic acid or 4% hydroquinone cream twice daily for eight weeks, plus sunscreen. Pregnancy and breastfeeding were excluded.¹

This was a specific cream comparison. It cannot establish the performance of a cosmetic serum with a different percentage or formula.

Did lighter patches mean clear skin?

Mean MASI scores fell 7.6 to 3.8 with azelaic acid versus 7.2 to 6.2 with hydroquinone. MASI combines affected area, darkness and pigment uniformity. The eight-week difference favored azelaic acid; its 95% confidence interval was 0.03–4.9 points. Month-one differences were not significant. No participant achieved complete clearance.¹

The trial does not establish recurrence rates after stopping. Its report provides no funding or conflict-of-interest declaration.¹

Ask what improvement would justify continuing your own treatment, and how it will be recorded. A score reduction, fewer visible patches and complete clearance are different targets.

Does the larger, older trial agree?

A 1991 double-blind study compared the same concentrations with sunscreen in 329 women over 24 weeks. Its abstract reports no significant between-treatment differences in overall ratings, lesion size or pigment intensity. That does not prove equivalence.²

The larger study’s full paper was unavailable for this review. The studies used different measures and durations; the smaller experiment does not settle which cream works best for every melasma pattern.

What belongs in the prescription discussion?

The US Azelex 20% cream label covers inflammatory acne, so prescribing it for melasma is off-label. It warns about skin irritation and isolated reports of hypopigmentation, meaning skin becoming lighter. Report abnormal color changes; stop and contact the prescriber for severe irritation.³

For hydroquinone, FDA⁴ says skin-lightening products are not approved for OTC sale in the US; prescription products are available through a healthcare provider.⁴

Sun protection remains part of treatment. The AAD recommends broad-spectrum, water-resistant SPF 30 or higher and tinted sunscreen containing iron oxide for visible-light protection. It warns that burning or stinging from skin care can irritate skin and darken spots.⁵

Skin, Head to Toe includes “What to Say at the Appointment”: bring your product and medication history, photographs of products, and pregnancy plans. Those details help the clinician assess the proposed cream. See the book.