Melasma is also known as chloasma and, more commonly, as the “mask of pregnancy.” All three names refer to the same condition: patches of darker skin that appear primarily on the face, driven by a combination of hormonal changes and sun exposure. The nickname “mask of pregnancy” comes from how frequently the condition develops during pregnancy, though it affects many people who have never been pregnant.
Why It Has Multiple Names
The term “melasma” comes from the Greek word for black, referring to the dark patches it produces. “Chloasma” is an older, less commonly used medical term for the same condition. You’ll still see it in some textbooks and clinical references, but most dermatologists now use “melasma” as the standard name regardless of the cause.
The phrase “mask of pregnancy” stuck because the condition so often appears during pregnancy, when hormone levels shift dramatically. But calling it only a pregnancy condition is misleading. Melasma also develops in women taking hormonal birth control, people undergoing hormone therapy, and sometimes in men. About 96% of melasma patients in clinical research are female, but men are not immune.
What Melasma Looks Like
Melasma shows up as larger, often symmetrical patches of darkened skin on the cheeks, forehead, upper lip, and chin. The patches tend to have irregular borders and a brownish or grayish-brown color, and they can cover a noticeable area of the face. This distinguishes melasma from sunspots (also called age spots), which are smaller, more defined dots caused purely by years of UV exposure, and from post-inflammatory hyperpigmentation, which is darkening that appears at the site of a previous injury, acne breakout, or rash.
What Causes It
Melasma happens when melanocytes, the cells responsible for producing skin pigment, become overactive and pump out excess melanin. The key drivers are hormones, sunlight, and genetics working together.
Estrogen plays a central role. It directly influences melanocytes through receptors on their surface, triggering signaling pathways that ramp up pigment production. This is why pregnancy, birth control pills, and hormone replacement therapy are such common triggers. Progesterone likely contributes as well, though estrogen’s role is better understood.
Sunlight is the other major factor, and it goes beyond just UV rays. Visible light, which makes up nearly half of the sunlight spectrum, also stimulates pigment-producing cells. This means you can worsen melasma through car windows, indoor lighting, and even digital screens. Visible light has a particularly strong effect on people with deeper skin tones.
Who Gets Melasma
Melasma is far more common in people with medium to dark skin tones. Globally, the overall prevalence is estimated at around 1%, but in higher-risk populations, that number jumps to anywhere from 9% to 50%. In India, prevalence reaches as high as 41%. Among Latino populations in the U.S., rates fall between 8% and 9%. An Arab-American community in Michigan showed a 15.5% prevalence rate. In China and Nepal, reported rates are 13.6% and 6.8%, respectively.
Genetics also matters. If close family members have melasma, your risk is higher. The condition most commonly appears between ages 30 and 46, though it can start earlier during pregnancy.
How Melasma Behaves During and After Pregnancy
When pregnancy triggers melasma, many women wonder how long it will last. In milder cases, the patches naturally fade over three to six months after delivery. But pigmentation can persist for a year or longer, especially if you’re breastfeeding (which maintains certain hormonal shifts) or getting regular sun exposure. Some women find the patches never fully disappear on their own, particularly after multiple pregnancies.
Most dermatologists recommend waiting until after breastfeeding to begin active treatment, since certain topical ingredients aren’t considered safe during that time. In the meantime, rigorous sun protection is the single most effective step you can take to prevent the patches from deepening.
Why Standard Sunscreen May Not Be Enough
Because visible light triggers melasma alongside UV rays, a regular SPF sunscreen only does part of the job. Standard sunscreens block UVA and UVB radiation but let visible light pass through. For melasma-prone skin, sunscreens containing iron oxides provide an added layer of protection by filtering visible light as well. Research published in the Journal of Drugs in Dermatology found that UV-only sunscreens may not be sufficient, and that iron oxide formulations make a meaningful difference in both appearance and progression for people with melasma or similar pigmentation conditions.
Tinted sunscreens are the easiest way to get iron oxide protection, since the tinting agents themselves contain these compounds. Reapplying every two hours during sun exposure and wearing a wide-brimmed hat further reduces the light reaching your skin.
Treatment Options
Melasma is notoriously stubborn to treat and prone to coming back even after successful clearing. Most treatment plans start with topical products that slow pigment production or speed up skin cell turnover. These are typically applied nightly over several months before visible improvement appears.
For cases that don’t respond well to topical therapy alone, oral tranexamic acid has become an increasingly popular option. Originally developed to control bleeding, this medication works by interrupting the signaling between UV damage and melanocyte activation. A network meta-analysis of six clinical trials found that the optimal regimen is 250 mg taken three times daily for 12 weeks. For people who have difficulty sticking to that schedule, twice-daily dosing may still offer benefit.
Chemical peels and certain laser treatments can also help, though lasers carry a risk of worsening pigmentation if not carefully calibrated for the patient’s skin tone. The most successful long-term outcomes combine active treatment with consistent sun and visible light protection, since without that foundation, melasma almost always returns.
Melasma vs. Similar Conditions
If you’re not sure whether what you’re seeing is melasma, the pattern and history usually provide clues. Sunspots are flat, distinct brown dots on sun-exposed areas like the hands, chest, and shoulders. They result from cumulative UV damage over years and don’t fluctuate with hormonal changes. Post-inflammatory hyperpigmentation leaves dark marks exactly where skin was previously inflamed or injured, such as the site of a healed pimple or eczema flare. It fades gradually as the skin remodels itself.
Melasma, by contrast, appears in broad, symmetrical patches concentrated on the central face, often worsens and improves in cycles tied to hormonal shifts and sun exposure, and tends to be more persistent than either sunspots or post-inflammatory darkening. The symmetry is one of its most recognizable features: if one cheek is affected, the other almost always is too.