Dark marks after pimples: why they form and fade

A pimple heals, and a flat brown, gray, red or pink spot stays behind. For many people this mark bothers them more than the pimple did. This guide explains what the mark is, why acne leaves it, and the steps that help it fade. It is part of Skinli's guide to hyperpigmentation, which covers every type of dark spot.

What a dark mark after a pimple is

The American Academy of Dermatology (AAD) describes it this way. When a pimple or other breakout clears, you may see a flat, colored spot where the acne was. The most common type is called post-inflammatory hyperpigmentation, often shortened to PIH. The name means extra color that appears after inflammation, the swelling and redness of a breakout.

The color depends on your skin tone. The AAD says the spot is usually red or pink on lighter skin. On medium or darker skin it is often brown, and it can be bluish gray. Some people get the opposite change: a flat spot that is white or lighter than their skin. Doctors call that hypopigmentation.

The surface of the skin tells you which type of mark you have. Run a finger over it in daylight.

What you see and feel	What it usually is	What happens next
Flat brown, gray or bluish spot	Post-inflammatory hyperpigmentation	Usually fades over months
Flat red or pink spot	A red mark after inflammation	Can stay for months, then fades
Flat spot lighter than your skin	Hypopigmentation	Usually fades over time
A dent or a raised, firm bump	An acne scar	Needs a dermatologist

Dents and raised bumps are scars, and they need different care. Skinli covers them in how to get rid of acne scars. The rest of this page is about the flat marks.

Why acne leaves dark spots

Skin gets its color from melanin, a pigment made by cells called melanocytes. The AAD explains that people with medium to dark skin tones get dark spots when something triggers their skin to make extra melanin. A healing pimple is one of the most common triggers. The AAD lists others too: an insect bite, a cut or burn, some medicines, and skin care products that irritate the skin.

A 2010 review of PIH in skin of color adds two details. First, the spot appears in the same place as the inflammation that caused it. Second, PIH can get worse with ultraviolet light from the sun, and with inflammation that lasts or keeps coming back. That is why a mark can darken while acne in the same area stays active.

Picking makes it worse

The AAD says that squeezing a pimple often pushes its contents deeper into the skin, and that this increases inflammation. More inflammation means a stronger trigger for extra color. It also raises the risk of scars and infection. Leaving pimples alone is one of the few steps that costs nothing and prevents new marks.

Red marks and brown marks

People with lighter skin often see red or pink marks instead of brown ones. The AAD says these red spots can linger for months, and that many people find them worse than the acne itself. Researchers call them post-inflammatory erythema, which means redness after inflammation.

The two kinds of mark can respond to the same care. In a 2024 trial of 72 people with mild to moderate acne, 15% azelaic acid gel used twice a day for 12 weeks reduced both red and brown acne marks, with few side effects. The trial was small, so treat it as one encouraging result.

Step 1: stop the acne that makes new marks

The AAD is direct about this: to get rid of hyperpigmentation caused by a skin condition, you must treat the skin condition first. When breakouts stop, the cause of new marks stops too. The 2010 review says the same thing, that care for PIH should begin with the condition underneath it.

For acne, that means a steady routine with one treatment at a time. Skinli's complete acne skincare routine covers the daily steps. Most treatments need time. The AAD says it takes at least 6 to 8 weeks before you start to see fewer breakouts.

Treating early matters most for darker skin. The AAD says that if acne becomes moderate to severe before treatment begins, people with skin of color have a higher risk of spots and patches of darker skin.

Step 2: sunscreen every morning

Sun makes dark marks darker and slower to fade. The AAD calls sunscreen essential. Put it on before you go outside, on all skin that clothing will not cover. Used this way, the AAD says, sunscreen can prevent new dark spots and help clear existing ones.

The AAD recommends a tinted sunscreen that contains iron oxide. Iron oxide is a mineral pigment that protects against visible light, the ordinary light we see, which the AAD names as a cause of dark spots. You find it in the list of inactive ingredients on the label. The AAD also asks for SPF 30 or higher, broad-spectrum protection and water resistance. If your skin is oily, pick a formula labeled non-comedogenic, which means it is made so it does not clog pores. Put it on again every two hours outdoors, and after swimming or sweating.

Skinli's plan uses the same rule: sunscreen SPF 30 or more every morning, because the sun makes marks darker and sunscreen lets them fade.

Step 3: add one ingredient that fades marks

Once the acne is under control and sunscreen is a habit, a fading ingredient works better. The AAD lists five that you can buy without a prescription:

• Azelaic acid
• Glycolic acid
• Kojic acid
• A retinoid, such as retinol, adapalene gel, tretinoin or tazarotene
• Vitamin C

Two of these also treat acne, which makes them a good fit for acne marks. The AAD says a retinoid applied to the skin can help lighten dark spots after acne clears, and that azelaic acid can treat those spots too. Adapalene 0.1% gel is sold without a prescription. The guide on how to start adapalene covers a slow start that limits irritation.

Skinli's 12-week plan follows this order. When the photo shows flat marks, the plan adds an azelaic acid 10% cream in the morning from week 5, before sunscreen, once the acne gels are part of the routine.

Irritation can cause new marks, so go slowly. Add one product at a time and patch test it first. The AAD's rule is short: if a product burns or stings when you put it on, stop using it.

The hub has one page for each fading ingredient: retinol and tretinoin, azelaic acid, vitamin C and niacinamide.

Track the fade with photos

Marks fade slowly, so it is hard to see the change from one day to the next. A photo once a month, taken in the same place, in the same light and at the same distance, makes the change easier to judge. Daylight from a window works well, and so does the same bathroom light every time. The guide on how to take acne progress photos walks through the setup, and Skinli's progress page keeps the photos in one place.

Compare photos that are at least a month apart. The AAD's timeline for a flat mark is counted in months, so a week is too short to judge. If a mark gets darker while you use a new product, check for irritation first, because irritated skin can make new color.

What to avoid

The AAD warns about three things:

• Skin products imported from other countries that contain steroids or mercury not listed on the label. The steroids can make skin thin and fragile or permanently discolored.
• Liquid bleach, which should never go on the skin.
• At-home chemical peels, microdermabrasion or laser devices on darker skin, which can cause permanent dark marks and light spots.

The FDA adds that no skin lightening product with hydroquinone is legally sold over the counter in the US. It has received reports of rashes, facial swelling and ochronosis, a skin discoloration that may be permanent, from these products.

When a dermatologist can help

Some marks stay even with good home care. The AAD says some dark spots need a prescription-strength treatment, and a dermatologist knows how to combine treatments safely. NICE, the body that writes clinical guidelines for England, advises doctors to consider a dermatologist referral for acne with pigment changes that persist.

See a doctor as well if the acne itself is deep and painful, if it leaves dents or raised scars, or if a spot looks different from your other marks. For how long each type of mark usually lasts, read how long dark marks take to fade.