Brown spots on your face are almost always caused by your skin producing too much melanin, the pigment that gives skin its color, in a concentrated area. The three most common reasons are sun damage, hormonal changes, and leftover marks from acne or other skin irritation. Which one is behind your spots depends on their size, shape, location, and what else is going on in your life.
How Brown Spots Form
Your skin contains cells called melanocytes that produce melanin. When something triggers these cells to go into overdrive, whether that’s UV light, hormones, or inflammation, they pump out excess pigment that collects in patches. With UV exposure, the process works like this: sunlight damages skin cells, which respond by sending a chemical signal to nearby melanocytes telling them to ramp up pigment production. That pigment is meant to act as a natural sunscreen, absorbing UV rays to protect your DNA. But when the process overshoots, you get visible dark spots instead of an even tan.
This same signaling pathway can be activated by hormones and even stress chemicals, which is why brown spots don’t always trace back to sun exposure alone.
Sun Spots (Solar Lentigines)
If your brown spots are flat, well-defined, and range from light yellow to dark brown, they’re likely solar lentigines, commonly called sun spots or liver spots (they have nothing to do with your liver). These typically measure 1 to 3 centimeters across and show up on skin that’s gotten the most sun over your lifetime: face, hands, forearms, chest, and shins. They often have a slightly uneven color within a single spot.
Sun spots are cumulative. Each one represents years of UV exposure catching up with you. They’re more common after age 40 but can appear earlier in people who’ve spent significant time in the sun or used tanning beds. Once they show up, they don’t fade on their own.
Melasma and Hormonal Spots
Melasma looks different from sun spots. It appears as larger, irregular patches rather than discrete dots, and it follows predictable patterns on the face. The most common pattern, affecting about 63% of people with melasma, is centrofacial, covering the forehead, cheeks, nose, and upper lip. About 21% of cases appear mainly on the cheekbones, and 16% along the jawline. The patches are usually symmetrical, showing up on both sides of the face.
Hormonal fluctuations are the primary driver. Melasma commonly appears during pregnancy (it’s sometimes called “the mask of pregnancy”), when starting or stopping birth control pills, or during hormone replacement therapy. But hormones aren’t the only trigger. Sun exposure is the single biggest factor in making melasma worse, and heat and visible light (from screens and indoor lighting) can also darken existing patches. Even air pollution plays a role by weakening the skin’s protective barrier, making it more vulnerable to sun damage.
The color of your melasma patches can tell you how deep the pigment sits. Light brown patches tend to be in the upper layers of skin and respond better to treatment. Grayish patches indicate deeper pigment that’s harder to treat. Dark brown patches are often a mix of both.
Marks Left by Acne and Skin Injuries
If your brown spots line up with places where you recently had a pimple, rash, or scratch, you’re dealing with post-inflammatory hyperpigmentation (PIH). Any time your skin is injured or inflamed, melanocytes in that area can overreact during the healing process, leaving behind a dark mark after the original problem clears up.
The most common triggers are acne, eczema, bug bites, burns, razor bumps, allergic reactions, and psoriasis. Even cosmetic procedures like chemical peels, laser treatments, and cryotherapy can cause PIH. This is especially common in people with darker skin tones, who have more active melanocytes.
The good news is that PIH from the upper skin layers typically fades on its own within 6 to 12 months. The bad news is that deeper PIH can take years to resolve, and some spots become permanent without treatment.
Medications That Cause Brown Spots
Certain medications can darken your skin, particularly on sun-exposed areas like your face. Common culprits include some antibiotics (especially minocycline and doxycycline), the heart medication amiodarone, certain blood pressure pills, anti-inflammatory drugs, antimalarial medications, and some cancer treatments.
Minocycline, frequently prescribed for acne, is one of the best-documented offenders. It can produce several different discoloration patterns, including muddy-brown patches specifically on sun-exposed skin. Other medications like amiodarone and certain antibiotics cause what’s called a phototoxic reaction, where the drug makes your skin abnormally sensitive to sunlight, leading to pigmentation changes over time. If your spots appeared after starting a new medication, that connection is worth investigating.
When a Brown Spot Could Be Skin Cancer
Most brown spots are harmless, but melanoma can disguise itself as an ordinary spot in its early stages. The National Cancer Institute recommends checking any new or changing spot against the ABCDE criteria:
- Asymmetry: one half doesn’t match the other
- Border: edges are ragged, notched, or blurred, or pigment spreads into surrounding skin
- Color: uneven shades of brown, black, tan, or patches of white, gray, red, pink, or blue
- Diameter: larger than 6 millimeters (about the size of a pencil eraser), though melanomas can be smaller
- Evolving: the spot has changed in size, shape, or color over recent weeks or months
A spot that checks even one of these boxes deserves a professional evaluation. Melanoma caught early is highly treatable, so acting quickly matters.
Topical Treatments That Fade Spots
The most effective topical treatments work by interfering with your skin’s pigment-production machinery. They block the enzyme (tyrosinase) that melanocytes need to manufacture melanin, essentially slowing the assembly line.
Hydroquinone is the most widely used prescription option and remains the standard against which others are measured. Over-the-counter alternatives include kojic acid (derived from fungi), arbutin (from bearberry plants), azelaic acid, and various forms of vitamin C. Retinoids speed up skin cell turnover, pushing pigmented cells to the surface faster so they shed sooner. Alpha hydroxy acids like glycolic acid work similarly by exfoliating the top layer of skin. Many dermatologists recommend combinations of these ingredients for better results than any single one alone.
Patience is essential with topical treatments. You’re waiting for your skin to cycle through its natural turnover process, which takes roughly four to six weeks per cycle. Visible improvement often takes two to three months of consistent use, sometimes longer for deeper pigmentation.
Professional Procedures
When topical treatments aren’t enough, chemical peels and laser treatments are the two main professional options. Both have trade-offs worth understanding before you commit.
Laser treatments, particularly Q-switched and fractional lasers, target melanin directly and tend to produce faster, more dramatic results. A meta-analysis of clinical trials found lasers were more effective than chemical peels at reducing melasma severity. However, up to 25% of patients treated with Q-switched lasers develop new dark spots as a side effect of the procedure itself, with darker-skinned patients at highest risk. Recurrence rates are also significant: up to 40% of patients see their melasma return within six months of laser treatment.
Chemical peels use acids like glycolic acid, salicylic acid, or trichloroacetic acid to remove the outer layers of skin, taking excess pigment with them. Results come more gradually, but peels carry a lower risk of triggering new hyperpigmentation. This makes them a safer starting point for people with darker skin tones or anyone nervous about the rebound darkening that lasers can cause.
Preventing New Spots
Whatever is causing your brown spots, UV exposure makes every type worse. Broad-spectrum sunscreen with SPF 30 or higher is the single most important step, applied daily even on cloudy days and even if you work indoors (visible light through windows can worsen melasma). Reapplying every two hours during direct sun exposure matters more than the initial application.
For melasma specifically, heat avoidance can be just as important as sun protection. Saunas, hot yoga, cooking over a hot stove, and even sitting close to a fireplace can trigger flares. A wide-brimmed hat provides more consistent protection than sunscreen alone, since it blocks both UV and visible light without needing reapplication. If hormonal birth control seems connected to your spots, discussing alternative contraception options with your provider could help prevent further darkening.