Melasma is a common skin condition that causes patches of dark, uneven pigmentation on the face. It develops when pigment-producing cells in the skin become overactive, depositing excess melanin in concentrated areas. The condition affects women nine times more often than men and is strongly linked to hormonal changes and sun exposure. While melasma isn’t harmful or painful, it can be persistent and difficult to treat, with recurrence rates between 41% and 60% even after successful treatment.
What Causes Melasma
Melasma starts with the cells that give your skin its color. These pigment-producing cells become hyperactive, churning out more melanin than surrounding skin. But the process isn’t as simple as one trigger flipping a switch. Multiple systems in the skin go haywire at once.
UV radiation from sunlight activates skin cells that then ramp up production of a growth factor called VEGF. This stimulates the formation of new blood vessels in the deeper layers of skin beneath melasma patches, and those extra blood vessels feed back into the cycle by producing even more VEGF. At the same time, aging skin cells in the affected area release a cocktail of inflammatory signals that further stimulate pigment production and break down the structural proteins (collagen) that normally keep the skin’s layers organized. This is why melasma tends to worsen over time without intervention: the underlying skin environment keeps reinforcing itself.
The Role of Hormones
Hormones are one of the strongest drivers of melasma, which is why the condition so frequently appears during pregnancy, while taking oral contraceptives, or during hormone therapy. Between 14.5% and 56% of pregnant women develop melasma, depending on ethnicity and geography, and 11.3% to 46% of oral contraceptive users experience it.
Both estrogen and progesterone play direct roles. Pigment-producing cells in melasma patches have more hormone receptors than normal skin, making them unusually sensitive to hormonal shifts. Estrogen accelerates pigment production, while progesterone ramps up the enzymes responsible for melanin synthesis, promotes the growth and migration of pigment cells, triggers vascular remodeling, and creates a pro-inflammatory environment in the skin. During pregnancy, a specific form of progesterone rises significantly, which may explain why melasma so commonly appears in the second or third trimester.
Where It Appears on the Face
Melasma patches are symmetrical, meaning they appear in roughly matching positions on both sides of the face. The discoloration has an irregular outline and uneven tone within the patches, typically ranging from light brown to dark brown depending on skin tone and how deep the excess pigment sits.
Three patterns describe where melasma shows up. The centrofacial pattern is the most common, affecting about 55% of people with melasma. It spreads across the forehead, cheeks, upper lip, nose, and chin. The malar pattern, seen in about 43% of cases, is limited to the cheeks and nose. The mandibular pattern, which involves the jawline, is rare at roughly 1.6% of cases.
How It Differs From Other Dark Spots
Not all facial discoloration is melasma, and the distinction matters because treatments differ. Post-inflammatory hyperpigmentation (PIH) is the dark mark left behind after a pimple, rash, burn, or other skin injury. PIH shows up wherever the inflammation was, so it follows the pattern of previous breakouts or irritation rather than appearing in the symmetrical, slow-spreading patches characteristic of melasma. PIH also tends to fade on its own over months, while melasma rarely resolves without active treatment and sun protection.
Sun spots (solar lentigines) are another common look-alike. These are small, well-defined brown spots caused by cumulative sun damage. They don’t spread in broad, irregular patches the way melasma does, and they stay relatively stable in color rather than fluctuating with hormonal changes or seasons.
How Melasma Is Diagnosed
Dermatologists can usually identify melasma by its appearance alone: the symmetrical distribution, irregular borders, and characteristic locations on the face are distinctive. To determine how deep the pigment sits, a Wood’s lamp (a handheld ultraviolet light) is sometimes used. When the dark patches become more prominent under the lamp, the excess pigment is concentrated in the outer layer of skin (epidermal melasma), which tends to respond better to topical treatments. When the patches show no change under the light, the pigment has settled deeper into the skin (dermal melasma), which is harder to treat. A mixed pattern, where patches show slight enhancement, indicates pigment at both depths.
Topical Treatments
Hydroquinone remains one of the most widely used topical treatments for melasma. It works by slowing pigment production in the affected areas. Concentrations of 2% to 4% are standard, with some formulations going up to 5%. You typically apply it once daily, and visible lightening should begin after five to seven weeks of consistent use. Most treatment plans continue for at least three months, and some extend up to a year. Hydroquinone is often combined with other active ingredients like a retinoid and a mild steroid in what dermatologists call a “triple combination” cream.
Other topical options include kojic acid, azelaic acid, and vitamin C formulations, which work through different mechanisms to reduce pigment production. These are sometimes preferred for people who can’t tolerate hydroquinone or who need a long-term maintenance option.
Oral Treatment for Stubborn Cases
For melasma that doesn’t respond well to topical treatments alone, an oral medication originally designed to reduce bleeding has shown real promise. Tranexamic acid, taken as a pill, works by interrupting some of the pathways that drive excess pigment production.
The most commonly studied dose is 250 mg twice daily. In a randomized, double-blind trial, 50% of patients taking oral tranexamic acid saw improvement over 12 weeks, compared to just 5.9% in the placebo group. Another study of patients with stubborn, treatment-resistant melasma found a 69% average improvement in severity scores. A larger study following patients for six months reported that about 65% achieved good to excellent results. The medication is generally well tolerated, though it’s not appropriate for everyone, particularly those with a history of blood clots.
Why Sunscreen Alone Isn’t Enough
Sun protection is the single most important factor in both preventing and managing melasma, but standard sunscreens have a gap. Most sunscreens only block ultraviolet light, and melasma is also triggered by visible light, the kind that comes from sunlight you can actually see and from screens. Research has shown that sunscreens containing iron oxide can protect against visible light-induced pigmentation in a way that even SPF 50+ UV-only sunscreens cannot.
For anyone dealing with melasma, a tinted sunscreen (which gets its color from iron oxide) applied daily provides meaningfully better protection than a non-tinted formula. This applies indoors too, since visible light passes through windows. Broad-brimmed hats and seeking shade during peak sun hours add another layer of defense. Without consistent, comprehensive sun protection, even successful treatments will eventually be undermined by new pigment production.
Long-Term Outlook
Melasma is a chronic condition. In a national survey of dermatologists, nearly half reported that their patients experienced recurrence rates between 41% and 60% after treatment. This doesn’t mean treatment is pointless. It means melasma management is ongoing rather than a one-time fix. Maintenance strategies typically involve continued use of a milder topical agent, rigorous daily sunscreen with visible light protection, and avoiding known triggers when possible. Many people find that melasma lightens significantly with the right combination of treatments but requires sustained attention to keep it from returning.