Melasma appears as flat, brown, or gray-brown patches on the face, most often on the cheeks, forehead, nose, and upper lip. The cause is a combination of genetic predisposition, ultraviolet (UV) light exposure, and hormonal changes. Sun exposure is the single most powerful trigger, and without strict sun protection, melasma will typically worsen or return after treatment.
What Causes Melasma On Your Face Key Triggers
Melasma happens when melanocytes — the cells that produce pigment in your skin — become overactive and produce too much melanin. In normal skin, melanin is made evenly and fades over time. In melasma-prone skin, those cells stay switched on, creating patches that can persist for years.
The key triggers are well documented. UV light tops the list. Heat, visible light, and hormonal shifts also play major roles. Each trigger acts on the same pigment-producing cells, but through slightly different pathways.
How UV Light Drives Melasma
Ultraviolet radiation is the dominant environmental trigger. UVB rays burn the skin surface, while UVA rays penetrate deeper into the dermis. Both stimulate melanocytes to produce more pigment.
What surprises many people is that even small amounts of sun exposure can maintain melasma. A few minutes of unprotected sun during a commute or through a car window is enough to keep pigment cells active. This is why melasma often returns in summer and fades somewhat in winter.
Visible light also matters. Research has shown that high-energy visible (HEV) light — the blue light from screens and sunlight — can trigger melasma in darker skin types. Most sunscreens do not block visible light, which is one reason melasma is so difficult to control.
Hormones: Estrogen and Progesterone
Hormonal changes are a well-established trigger. Melasma is far more common in women than in men, and it often first appears during pregnancy, while taking oral contraceptives, or during hormone replacement therapy.
Pregnancy-related melasma is sometimes called the “mask of pregnancy.” It typically appears in the second or third trimester and may fade after delivery, though it often does not disappear completely.
Estrogen and progesterone do not cause melasma on their own. They make melanocytes more sensitive to UV light. A woman who has never had melasma can develop it while pregnant even with minimal sun exposure. The same hormonal sensitivity explains why some women see melasma flare during their menstrual cycle.
Thyroid disease has also been linked to melasma. Some studies have found a higher rate of thyroid dysfunction in people with melasma, though the connection is not fully understood.
Genetics and Skin Type
Melasma runs in families. If your mother or sister has it, your risk is higher. This genetic component helps explain why some people develop melasma with minimal sun exposure while others spend decades in the sun without a single patch.
Skin type matters as well. People with Fitzpatrick skin types III to V — medium to dark skin tones — are most commonly affected. These skin types have more active melanocytes to begin with, which offers some natural sun protection but also makes pigment overproduction more likely.
People with very fair skin can develop melasma too, but it is less common. The condition is not limited by ethnicity or geographic origin.
Other Triggers: Heat, Cosmetics, and Medications
Heat is an underappreciated trigger. Saunas, steam rooms, hot yoga, and even hot water on the face can worsen melasma. Heat increases blood flow and inflammation in the skin, which can stimulate pigment production.
Some cosmetics can trigger a form of pigmentation called pigmented contact dermatitis. This is not true melasma, but it looks similar. Fragrances, essential oils, and certain preservatives can cause inflammation that leads to dark patches. If your pigmentation appeared after starting a new skincare product, this is worth discussing with a dermatologist.
Certain medications can also trigger melasma or melasma-like pigmentation. Some seizure medications, certain antibiotics, and some cancer treatments are known to cause skin darkening. Anti-seizure drugs and photosensitizing medications are the most commonly reported culprits.
Why Melasma Is So Hard to Treat
Melasma is stubborn because the triggers are ongoing. You can stop taking a medication or deliver a baby, but you cannot stop being exposed to sunlight or visible light. The pigment cells remain primed and ready to reactivate.
Another reason melasma is difficult to treat is that the pigment sits at different depths in the skin. Epidermal melasma is closer to the surface and responds better to treatment. Dermal melasma sits deeper and is much more resistant. Most people have a mixture of both.
Some research also suggests that melasma involves more than just pigment production. The affected skin shows signs of solar elastosis — sun damage to the connective tissue — and an abnormal basement membrane. This means melasma is not purely a pigment problem. It is a sign of structural changes in the skin.
Treatment Basics and What to Expect
Sun protection is the foundation of every melasma treatment plan. Without it, no topical cream, procedure, or medication will work long term. A broad-spectrum sunscreen with SPF 30 or higher, applied every morning and reapplied every two hours, is the minimum standard of care.
For people with darker skin, a tinted sunscreen that contains iron oxides offers additional protection against visible light. This is an important detail that many people miss.
Topical treatments are the first-line therapy. Hydroquinone is the most studied and effective ingredient, available in over-the-counter strengths of 2% and prescription strengths of 4% or higher. It works by blocking an enzyme needed for melanin production.
Other topical options include azelaic acid, kojic acid, and tranexamic acid. These are less potent than hydroquinone but can be useful for maintenance or for people who cannot tolerate hydroquinone.
Procedures such as chemical peels and laser therapy can help, but they carry risk. In some cases, lasers and peels can make melasma worse by causing inflammation, which triggers more pigment production. These treatments should only be performed by a dermatologist experienced in treating melasma in your skin type.
Oral tranexamic acid has gained attention in recent years. It is taken as a pill and works by reducing the inflammatory signals that stimulate melanocytes. Some clinical trials have shown good results, but it is not FDA-approved for melasma, and it carries a small risk of blood clots. It is not a first-line treatment.
Expect treatment to take months, not weeks. Melasma rarely clears completely. The goal is usually significant lightening and control rather than total elimination.
Prevention and Long-Term Management
Prevention is more effective than treatment. If you are prone to melasma, daily sunscreen use should be non-negotiable. Reapply it even on cloudy days and when indoors near windows.
Wearing a wide-brimmed hat adds physical protection that sunscreen alone cannot provide. It blocks UV and visible light from above, which is where most facial sun exposure comes from.
If you are considering oral contraceptives or hormone replacement therapy and have a history of melasma, discuss this with your doctor. You may still be able to use these medications, but you should know that melasma can flare.
Regular use of a gentle skincare routine matters. Harsh scrubs and irritating products can trigger inflammation, which worsens pigmentation. Fragrance-free, non-comedogenic products are the safest choice.
Frequently Asked Questions
Can melasma go away on its own?
Melasma can fade on its own when the trigger is removed, such as after pregnancy or stopping birth control pills, but it often persists for years. Sun exposure will keep it active even if the original trigger is gone.
Is melasma a sign of liver disease?
No. Melasma is not caused by liver disease, and the two conditions are not connected. This is a common myth with no medical evidence behind it.
Does melasma get worse with age?
Melasma can worsen with age because cumulative sun exposure adds up over time. However, it often becomes less noticeable after menopause when hormone levels drop.
What is the fastest way to get rid of melasma?
There is no fast cure for melasma. The most effective approach is strict sun protection combined with prescription topical treatments, and even then, visible improvement typically takes eight to twelve weeks.
