What Causes Melasma? Triggers and How to Keep It From Coming Back

Melasma is caused by a mix of sun and visible light, hormones and genetics, which together make pigment cells overproduce melanin in patches on the face. The most common triggers are sun exposure, pregnancy, birth control pills and some medicines, and it is far more common in women aged 20 to 40 with medium to darker skin. Melasma cannot be cured, but it can be faded and kept from coming back, and the key is managing the triggers every day, not just treating the patches.

This guide explains what causes melasma, the triggers that make it flare, how to tell it from other dark spots, and the daily habits that keep it from returning.

What melasma looks like

Melasma causes brown or gray-brown patches, usually symmetrical on both sides of the face: the cheeks, forehead, bridge of the nose, upper lip and chin. It can also appear on the forearms and neck. The patches are flat, do not itch or hurt, and often darken in summer and lighten in winter.

What causes melasma?

• SunlightUltraviolet light makes pigment cells produce more melanin. Even brief daily sun can keep melasma active.
• Visible lightThe light from the sun that you can see, including blue light, can also darken melasma, especially in darker skin, which is why tinted sunscreen helps.
• PregnancyRising estrogen and progesterone trigger the “mask of pregnancy,” which may fade after birth.
• Birth control and hormone therapyEstrogen and progesterone medicines can trigger or worsen it.
• Other medicinesSome anti-seizure drugs and medicines that make skin sun-sensitive.
• GeneticsMelasma runs in families and is more common in people of Latin, Asian, Black and Native American heritage.
• Thyroid diseaseMay raise the risk; treating it sometimes helps.
• Tanning beds and irritationTanning beds, harsh or fragranced products that irritate skin, and possibly stress can make it worse.

Heat is also commonly reported to worsen melasma, so hot yoga, saunas and cooking over a hot stove may play a part for some people, although the evidence is less clear than for sunlight.

Melasma vs other dark spots

Condition	Pattern	Cause
Melasma	Blotchy, symmetrical patches on cheeks, forehead, lip	Hormones, sun and visible light, genetics
Sun spots	Individual, well-defined spots on sun-exposed skin	Years of sun; see age spots
Post-acne marks	Flat marks where pimples were	Inflammation; see hyperpigmentation
Freckles	Small, scattered, fade in winter	Genetics and sun

The distinction matters, because strong lasers and intense light that clear sun spots can make melasma darker.

How to keep melasma from coming back

1. Sunscreen every day, all year: broad-spectrum SPF 30 or higher, tinted with iron oxides to block visible light. Reapply every two hours outdoors, and do not skip cloudy days or car journeys.
2. Shade and a wide-brimmed hat: sunscreen alone is not enough in Southern California sun.
3. Gentle skincare: fragrance-free products, no harsh scrubs or waxing on the face, which can irritate and darken patches.
4. A maintenance brightening routine: azelaic acid, vitamin C, niacinamide, kojic acid or a retinoid, as your provider recommends.
5. Review hormone medicines with your doctor if melasma started with the pill or hormone therapy.
6. Treat in cooler months and keep up maintenance in summer.

How melasma is treated

Treatment starts with prescription creams such as hydroquinone, often in a triple cream with tretinoin and a mild steroid, or gentler options like azelaic acid. For stubborn melasma, tranexamic acid tablets can help, though people with a history of blood clots should not take them. Depigmentation peels such as Cosmelan MD and gentle laser or light treatments can be added with care. Results usually take 3 to 12 months. See melasma treatment in Carlsbad, HALO for melasma and chemical peels for dark spots.

Cost at Glow Theory

VIP members pay $850 for Cosmelan MD. Melasma treatment is cosmetic, so it is not usually covered by insurance.

Melasma care in Carlsbad

Our dermatology team confirms melasma, looks for triggers, and builds a gentle, long-term plan for your skin type. Book a consultation at our studio on El Camino Real in South Carlsbad.