How to treat melasma — and why it requires a different approach.

Melasma is a chronic pigmentary condition involving the overproduction of melanin in clusters of hyperactivated melanocytes. It is common, recurrent, and often misunderstood — and the treatments that work for other forms of hyperpigmentation frequently underperform on it.

Understanding why melasma is difficult to treat is the first step toward treating it effectively.

What melasma is — and why it behaves differently

Unlike post-inflammatory hyperpigmentation — which is triggered by a specific injury and tends to resolve with treatment and time — melasma persists because its triggers are continuous.

Two primary drivers maintain melasma: ultraviolet light and hormonal stimulation. UVA radiation (present year-round, penetrating glass and cloud cover) activates melanocytes regardless of whether burning occurs. Oestrogen and progesterone — from oral contraceptives, hormone replacement therapy, and pregnancy — directly stimulate melanocyte activity through oestrogen receptors in the skin. Remove the SPF, or continue the hormonal trigger, and melasma reactivates.

This is why melasma is considered a chronic condition to manage rather than a problem to solve once.

SPF — the non-negotiable foundation

No topical treatment for melasma works reliably without daily, broad-spectrum sun protection. This is not rhetorical emphasis — it is the mechanistic reality. UV exposure reactivates the melanocyte network every day. Topical brightening actives work by slowing or interrupting melanin synthesis downstream. If UV is continuously signalling melanin production upstream, the downstream intervention cannot keep pace.

Broad-spectrum SPF 50 applied every morning — and reapplied if outdoors for extended periods — is the most important single action for melasma management. It is also the part most consistently underemphasised in treatment protocols.

Tinted mineral SPF containing iron oxides offers additional benefit for melasma specifically: visible light — in addition to UV — has been shown to stimulate melanin production in darker skin tones. An iron-oxide-tinted SPF blocks both.

First-line topical actives

The most evidence-supported topical approach to melasma targets melanin synthesis through multiple pathways simultaneously. No single active resolves melasma on its own.

Tranexamic acid (2–5%). The most robustly evidenced topical for melasma. It blocks the plasmin-driven paracrine signalling pathway between keratinocytes and melanocytes, reducing the UV-stimulated upregulation of melanin production. Does not cause photosensitisation; stable at AM and PM. Multiple randomised controlled trials demonstrate efficacy comparable to kojic acid with better tolerability.

Azelaic acid (10–20%). Two mechanisms relevant to melasma: competitive tyrosinase inhibition and selective anti-proliferative cytotoxicity on hyperactivated melanocytes. The 15–20% prescription concentration has level I evidence for melasma. 10% OTC is meaningfully effective. Not photosensitising; pregnancy-safe at appropriate concentrations.

Niacinamide (4–10%). Inhibits the transfer of melanosomes from melanocytes to surrounding keratinocytes — addressing the downstream distribution step rather than synthesis. Additive rather than redundant when combined with tranexamic acid or azelaic acid.

Vitamin C (10–20% L-ascorbic acid). Tyrosinase inhibition via copper chelation, plus antioxidant interception of UV-generated reactive oxygen species. Also addresses free radical-driven melanocyte stimulation that occurs alongside direct UV activation.

These four target separate points in the melanogenesis pathway. A protocol combining two or three — SPF as the base, tranexamic acid AM/PM, niacinamide AM/PM, azelaic acid PM — addresses the mechanism more comprehensively than any single active.

What does not work — and what makes melasma worse

Physical exfoliation — scrubs, dermaplaning, microneedling without careful preparation — can generate micro-inflammation that triggers further melanocyte activation, worsening melasma or causing post-inflammatory hyperpigmentation on top of it.

Strong AHAs and chemical peels applied without rigorous sun protection can have the same effect, particularly in darker skin tones. Glycolic acid at high concentrations without sustained SPF maintenance frequently worsens melasma after initial surface improvement.

Stopping sun protection once the skin looks clearer is the most common cause of recurrence. The melasma network is not resolved — it is suppressed. UV reactivation restores it quickly.

Realistic expectations

Melasma treatment with well-chosen topicals and consistent SPF produces gradual improvement over 8–16 weeks. Significant clearance is achievable in many cases. Complete resolution is rare with topicals alone, particularly for dermal melasma — which has a blue-grey tint and sits deeper than epidermal melasma, and responds more slowly to surface-acting ingredients.

If surface improvement is slow after 12 weeks of consistent treatment, consultation with a dermatologist — who can assess melasma depth and discuss prescription options — is appropriate.

Maintaining results

Because melasma is chronic, maintenance is the work. SPF is permanent. Active treatment cycles can be reduced in intensity once improvement is visible — but stopping altogether without SPF maintenance invites recurrence within weeks to months.

The practical goal is not resolution but management. Most people who are consistent with SPF and appropriately chosen actives achieve a significant, sustainable improvement — and learn to treat it as a condition to tend rather than a problem to cure.