Acne scars: types, treatments, and what to expect

Treatment can make acne scars less noticeable. Whether a mark will fade on its own depends on what acne has left behind. Flat brown or red marks often fade over months, although some last longer. Depressed or raised scars change the skin’s structure and may persist. No treatment can promise to erase them completely. The best approach depends largely on the type of scar.

What are acne scars?

Acne scars develop when an inflamed lesion damages the skin and healing changes its structure. This can leave a depression, called an atrophic scar, or a raised area, such as a hypertrophic scar or keloid. Why one lesion heals without an obvious mark while another scars is not fully understood. Several partly competing explanations have been proposed. Source Acne overview

Acne is among the world’s most common skin conditions. An estimated 231 million people had acne in 2019. A review of 37 studies involving 24,649 people with acne found that about 47% had some degree of scarring. Pits and larger depressions can therefore remain a concern long after inflammatory breakouts have settled. These prevalence figures describe particular datasets, not a prediction for every person with acne. Source Source

Scars or dark marks: why the distinction matters

A structural scar changes the skin’s contour: it is depressed or raised. Flat brown marks instead reflect excess pigment after inflammation, also called postinflammatory hyperpigmentation or reactive hypermelanosis. Pink or red marks usually involve vascular changes and are called postinflammatory erythema. Neither necessarily has the indentation or elevation of a scar. Hypermelanosis refers to pigment, not redness. Source Source

That distinction helps guide treatment. Options for dark pigment marks include topical hydroquinone, retinoids, and azelaic acid, as well as selected chemical peels and light-based procedures. Many pigment marks also fade over months without a procedure, although deeper or persistent pigmentation can take longer. What looks like an “acne scar” may therefore be a change in color rather than texture. Source

How do acne scars form?

A deep or persistent inflammatory acne lesion can damage the dermis, the deeper layer of skin. If repair leaves too little supporting collagen, a depression may remain. Excess collagen deposition can produce a raised scar. In either case, healing after inflammation has altered the skin’s structure. Source

New scars can appear within months. In a six-month split-face randomized trial, each participant used adapalene 0.1% plus benzoyl peroxide 2.5% on one side of the face and the gel vehicle, the base without those active ingredients, on the other. Atrophic scar counts remained stable on the active-treatment side but increased by about 25% on the vehicle side. Preventing new scars therefore begins with treating active acne. This was not a comparison with a completely untreated face. Source

Who is more likely to develop scars?

Several characteristics are associated with more frequent or more extensive scarring. Studies often express these associations as odds ratios. Odds compare an event occurring with it not occurring; an odds ratio compares those odds across groups. It is not the same as a proportional increase in probability.

• In the pooled review, severe acne was associated with 5.51 times the odds of scarring, and moderate acne with 2.34 times the odds, compared with milder acne. Source
• Men had 1.58 times the odds in the same analysis.
• A family history of acne was associated with 2.73 times the odds.
• In a clinical study of 269 people, those whose acne began in adolescence and those who were younger when assessed had more scarring. Overall, 71.3% of that clinical group had scars. Source
• Persistent dark marks and redness after individual acne lesions were associated with more scarring in the same group. More about erythema

The pooled estimate of around 47% and the 71.3% in one clinical sample are not directly comparable. The populations and distribution of acne severity differ. The numbers do not necessarily contradict each other, and neither can tell an individual exactly what will happen to their skin.

What types of acne scars are there?

Acne can leave depressed scars, raised scars, or flat marks. Strictly speaking, the flat marks are not scars. Structural changes are usually grouped into atrophic scars, which are depressed, and raised forms such as hypertrophic scars and keloids. Their shape helps determine what treatment can achieve. Source

Depressed scars: ice pick, boxcar, and rolling scars

Atrophic scars reflect loss or inadequate repair of supporting tissue during healing. They are the most common scars after inflammatory acne and are usually divided into three forms. Source

• Ice pick scars are narrow, deep, V-shaped depressions that taper into the dermis. They are especially deep relative to their width, often measure less than 2 mm across, and commonly occur on the cheeks. Source
• Boxcar scars are wider, round or oval depressions with sharply defined, nearly vertical edges. They can be shallow or deep and are common on the cheeks and temples.
• Rolling scars are broad, relatively shallow depressions that give the skin an uneven, wavy appearance. Fibrous bands beneath the skin pull its surface downward, creating shadows that change with the lighting. The lower cheeks and jawline are common sites.

Treatment therefore depends on shape as well as overall severity. Different procedures address different structural features, and clinicians often combine them to suit the mix of scars present. Source Source

Raised scars: hypertrophic scars, keloids, and papular scars

Excess collagen deposition during healing can create firm, raised scar tissue. Other small raised scars can have a different appearance, so an examination matters. Source

• Hypertrophic scars are firm, raised, and pink to skin-colored. They stay within the boundaries of the original lesion and may flatten somewhat over time.
• Keloids extend beyond the original injury into surrounding skin. They may itch or feel tender and have a particular tendency to recur after removal. Source
• Papular scars are small, soft, skin-colored or lighter bumps, usually only a few millimeters wide. They can be subtle or mistaken for active acne and commonly occur on the upper trunk. Source

Raised acne scars are especially common on the trunk. Scars below the neck can behave differently from facial scars and may need a different approach. A systematic review of keloid treatment supports silicone gel or sheets together with corticosteroid injections as an initial treatment. That finding should not automatically be extended to every hypertrophic or papular scar. Excision followed promptly by radiotherapy is a specialist option for selected resistant keloids, not a routine treatment for ordinary acne marks. Source Source

Flat marks: postinflammatory hyperpigmentation and erythema

Brown or gray-brown marks after acne are called postinflammatory hyperpigmentation. Pink or red marks are called postinflammatory erythema. “Postinflammatory” means after inflammation. Both are flat color changes rather than structural scar tissue. The pigment review addresses the brown marks; the erythema review addresses the red ones. Source Source

Skin type influences which changes are most noticeable. Hyperpigmentation is more common in Fitzpatrick skin types III–VI, while erythema is often more apparent in lighter skin. Either can persist and feel more troubling than the original acne. Vascular lasers, other light-based procedures, and some topical treatments have shown potential for post-acne redness, but the evidence is limited and more randomized trials are needed. Source Source

How is acne scar severity assessed?

A commonly used qualitative grading system has four levels, from flat discoloration through mild, moderate, and severe changes. Grade 1 includes color changes without structural scarring. Grades 2–4 consider the shape and extent of scars, as well as practical questions: Can makeup conceal them? Are they visible at a normal conversational distance? Source

Grading provides a shared way to describe the skin and helps frame the discussion before a procedure. It does not, by itself, identify one treatment that suits everyone in the same category.

What helps acne scars?

The choice of treatment depends on the scar type. Clinicians often combine procedures because each may address a different feature, and combinations can improve results in selected situations. However, the comparative evidence for many combinations remains limited. The realistic goal is to make scars less noticeable; complete removal cannot be promised. Source Source

At-home treatments: what do the studies show?

Some of the strongest topical-treatment evidence concerns preventing further scarring while treating active acne. In a 24-week split-face study, adapalene 0.3% plus benzoyl peroxide 2.5% gel reduced atrophic scar counts by 15.5% from baseline. Counts increased by 14.4% on the side treated with the inactive vehicle. At week 24, 32.9% of active-treatment sides were rated clear or almost clear on the Scar Global Assessment, compared with 16.4% of vehicle-treated sides. These percentages describe assessment categories, not a 32.9% reduction in every participant’s scars. Treatment-related irritation was also reported; choice and use should be discussed with a clinician. Source

For postinflammatory dark marks, hydroquinone, retinoids, and azelaic acid may be options. Daily sun protection can help prevent worsening and support improvement of pigment changes. Visible light, as well as ultraviolet radiation, can contribute to pigmentation in darker skin tones. That does not mean the two types of light have equal effects in every setting. Source Source

A cream cannot simply fill in an established deep depression. Topical treatments are particularly useful for controlling new acne and improving discoloration; any improvement in established structural scars is more limited and depends on the product and situation.

Office procedures matched to the scar type

Two people with similar acne histories may need different procedures because they have different scars. The options below describe published approaches, not a universal treatment order.

Scar type	Procedure used in practice	Reported study findings	Realistic expectations
Rolling scars	Subcision releases fibrous bands beneath the scar	A review of 16 clinical-trial reports found benefit; needle and cannula techniques had comparable efficacy. Source	Combining it with selected fillers, microneedling, or suction may improve results or reduce renewed depression; outcomes and adverse effects vary.
Boxcar and mixed atrophic scars	Fractional laser resurfacing	A review of seven studies reported 30%–70% improvement in appearance for most patients. A separate CO2 versus Er:YAG meta-analysis found an odds ratio of 1.81 for treatment response favoring CO2. Source Source	The 2024 comparison reported greater pain and longer redness with CO2, but shorter measured downtime. Those outcomes are distinct and should not be generalized to every device, setting, or patient.
Widespread atrophic scarring	Microneedling	Nine randomized trials reported improvement with microneedling alone or in combinations; no serious adverse effects were reported in those studies. Source	Larger trials with longer follow-up are needed. No serious events in small studies does not mean there is no procedural risk.
Depressed scars with volume loss	Hyaluronic acid-based fillers	A randomized split-face trial found reductions in scar volume. Source	How quickly changes appear depends on the product; the study does not establish a permanent result.
Keloids; other raised scars need separate assessment	Silicone gel or sheets with injections of corticosteroid into the scar	A review of 108 prospective studies supported this as an initial approach for keloids. The review does not establish the same recommendation for every hypertrophic scar. Source	Excision with prompt radiotherapy is a specialist option for selected resistant keloids.

Chemical peels are sometimes combined with other procedures. In one randomized trial, microneedling with a 35% glycolic acid peel produced similar overall scar improvement to microneedling with a 15% trichloroacetic acid peel. Skin texture improved more in the glycolic acid group. These are clinician-performed interventions, not instructions for using concentrated acids at home. Source

Microneedling combined with platelet-rich plasma has also been studied. In a meta-analysis, the odds of improvement greater than 50% were 2.97 times those with microneedling alone. The odds ratio for patient satisfaction was 4.15. There was no statistically significant difference in severe redness or swelling between groups. These relative odds are not the probability that a particular person will improve. Source

Resurfacing procedures can cause redness, swelling, and postinflammatory pigmentation. Many short-term reactions settle over weeks, but duration varies; pigment changes can persist longer. Skin tone, device settings, technique, and aftercare all matter when discussing the recovery plan. Source

Which treatments have limited evidence?

Several heavily promoted treatments have little supporting evidence. A systematic evidence review placed fractional laser and radiofrequency approaches among the better-supported options for atrophic scars, while still describing a varied and imperfect evidence base. A favorable assessment of safety in a review is not a guarantee of a risk-free procedure. Source

Home remedies such as lemon juice, baking soda, coconut oil, and toothpaste do not have controlled-trial evidence showing that they smooth established scars. Many combinations used in practice also depend partly on clinical experience because comparative trials are limited. A lack of evidence does not prove that an approach can never have an effect, but it cannot justify a promise of benefit. Source

How long do acne scars take to fade?

Flat marks often fade over months as pigment changes or vascular redness settle, although both can persist. Structural depressions and raised scars may remain. Hypertrophic scars sometimes become flatter over time, so their appearance can change without a procedure, but that is not the same as complete disappearance. The natural history of pigmentation, erythema, and structural scars should be considered separately. Source Source Source

Scar treatment often involves several sessions, and even similar procedures can have different timelines. In a split-face filler trial, a conventional cross-linked hyaluronic acid filler reduced scar volume earlier. A complex combining high- and low-molecular-weight hyaluronic acid produced more evident improvement at later visits. That comparison concerns the tested products and follow-up period, not a universal schedule for every filler. Source

How can you reduce the risk of acne scars?

Treating active inflammatory acne early and consistently is one of the best-supported approaches. A 24-week randomized trial found fewer scars with active topical treatment. A separate clinical observational study also found less scarring among people who had received systemic isotretinoin, but an observational association alone cannot establish prevention. Whether isotretinoin is appropriate requires clinical assessment; this finding is not a reason to start it independently. Source Source

In everyday care, that means:

• Address active inflammatory acne early rather than simply waiting for it to disappear.
• Have deep, painful, or persistent lesions assessed. Moderate and severe acne are particularly associated with scarring. Source
• Protect the skin from the sun each day to help prevent worsening of postinflammatory pigmentation. Source
• Avoid squeezing or picking acne lesions.

What is associated with more severe scarring?

Picking, persistent redness, and greater acne severity have been associated with facial scarring. One cross-sectional study reported these relationships as adjusted odds ratios, meaning that the analysis accounted for other measured factors. Adjustment does not turn an observational finding into proof of causation.

• Sometimes squeezing or picking lesions was associated with an adjusted odds ratio of 2.69 for facial acne scarring. Source
• Post-acne erythema was associated with an adjusted odds ratio of 4.46 in the same analysis.
• Moderate acne had an odds ratio of 3.51, and severe to very severe acne 8.98. These were severity categories, not specifically categories of untreated acne.
• Sun exposure can worsen or prolong pigment marks. That concerns discoloration, not proof that sunlight deepens an existing structural scar. Source

When should you see a dermatologist, and what should you ask?

Even mild scarring can be distressing and is a reasonable reason to seek advice. In a population-based survey of 723 adults with facial acne scars but no active acne, greater scar severity was associated with more disruption to quality of life. Significant effects were present even with mild scars. Overall, 74.8% worried that their scars would not go away, and 68.0% felt self-conscious about them. Source

Active breakouts, deep or painful lesions, and raised scars extending beyond their original boundaries also warrant assessment.

Five questions can make a consultation more useful:

1. Which scar types do I have, and how extensive are they?
2. Which procedures match those types?
3. How many sessions are realistic, and how much improvement do studies support?
4. What adverse effects and downtime should I expect, and how long might they last?
5. Does my active acne need to be controlled before scar treatment begins?

Frequently asked questions

Do acne scars go away on their own?

Depressed and raised scars change the skin’s structure and may persist. Hypertrophic scars can flatten somewhat, but that is not a promise of complete spontaneous resolution. Flat brown or red marks often fade over months, though some take longer. Brown marks are postinflammatory hyperpigmentation; red marks are postinflammatory erythema. Neither is the same as structural scar tissue. Source Source Acne overview Erythema guide Source Source

Can acne scars be removed permanently?

No treatment can reliably promise complete, permanent removal. The more realistic aim is improvement in appearance. Combinations may help selected scar patterns, but comparative evidence is limited. A fractional laser review reported 30%–70% improvement for most treated patients, which describes partial improvement rather than erasure. Several sessions may be needed, and individual results vary. Source Source

What types of acne scars are there?

Structural scars can be depressed or raised, reflecting how tissue is lost or rebuilt during healing. Depressed types include ice pick, boxcar, and rolling scars. Raised forms include hypertrophic scars, keloids, and small papular scars. Flat brown or red marks can also remain after acne, but these are color changes rather than scar tissue. Source Source

How common are acne scars?

A review of 37 studies involving 24,649 people with acne found scars in about 47%, or roughly half. In one clinical study of 269 people, the figure was 71.3%. The samples and acne severity distributions differed, so the numbers are not directly comparable. Acne itself affected an estimated 231 million people worldwide in 2019. Source Source Source

Why do some people develop acne scars and others do not?

The reasons an individual lesion heals one way rather than another are not fully understood. Certain characteristics are associated with more scarring. A meta-analysis reported odds ratios of 5.51 for severe acne and 2.34 for moderate acne compared with milder disease, 1.58 for male sex, and 2.73 for a family history of acne. Odds ratios are not equivalent increases in probability. Younger age, adolescent onset, and persistent pigment changes or redness were also associated with scarring in a clinical sample. These relationships cannot predict an individual’s outcome with certainty. Source Source

How can I lower my risk of acne scars?

Early treatment of active inflammatory acne has the best direct evidence here. In a 24-week split-face trial, adapalene 0.3% plus benzoyl peroxide 2.5% reduced atrophic scar counts by 15.5%, while counts increased by 14.4% on the vehicle-treated side. In a separate six-month trial using adapalene 0.1% plus benzoyl peroxide 2.5%, counts remained stable with active treatment and rose by about 25% with vehicle. Daily sun protection can also help with postinflammatory pigment changes, which are different from structural scars. Source Source Source

Does squeezing pimples cause scars?

Squeezing and picking are associated with scarring. In a cross-sectional study of 225 people with acne, sometimes squeezing or picking had an adjusted odds ratio of 2.69 for facial scars. The corresponding odds ratios were 4.46 for post-acne erythema and 8.98 for severe to very severe acne. Although the analysis adjusted for measured factors, it cannot establish cause and effect. Leaving inflamed lesions alone and treating active acne is more sensible than relying only on products applied after scars have formed. Source

Which office procedure is best?

There is no single best procedure for every scar. Subcision can release the fibrous bands beneath rolling scars; a review of 16 clinical-trial reports found benefit. Microneedling for atrophic scarring was supported by nine randomized trials in another review. Hyaluronic acid-based fillers may help selected depressed scars, while silicone and intralesional corticosteroids are options for keloids. A comparison of fractional lasers reported higher response odds with CO2 than Er:YAG (odds ratio 1.81), alongside differences in pain, redness, and recovery. None of these findings guarantees a particular outcome for an individual. Source Source Source Source Source

Sources

• Fabbrocini G, Annunziata MC, D’Arco V, et al. (2010). Acne scars: pathogenesis, classification and treatment. Dermatology Research and Practice, 2010, 893080. https://doi.org/10.1155/2010/893080 PubMed
• Chen H, Zhang TC, Yin XL, et al. (2022). Magnitude and temporal trend of acne vulgaris burden in 204 countries and territories from 1990 to 2019: an analysis from the Global Burden of Disease Study 2019. British Journal of Dermatology, 186(4), 673–683. https://doi.org/10.1111/bjd.20882 PubMed
• Liu L, Xue Y, Chen Y, et al. (2023). Prevalence and risk factors of acne scars in patients with acne vulgaris. Skin Research and Technology, 29(6), e13386. https://doi.org/10.1111/srt.13386 PubMed
• Kaufman BP, Aman T, Alexis AF (2018). Postinflammatory hyperpigmentation: epidemiology, clinical presentation, pathogenesis and treatment. American Journal of Clinical Dermatology, 19(4), 489–503. https://doi.org/10.1007/s40257-017-0333-6 PubMed
• Dréno B, Tan J, Rivier M, Martel P, Bissonnette R (2017). Adapalene 0.1%/benzoyl peroxide 2.5% gel reduces the risk of atrophic scar formation in moderate inflammatory acne: a split-face randomized controlled trial. Journal of the European Academy of Dermatology and Venereology, 31(4), 737–742. https://doi.org/10.1111/jdv.14026 PubMed
• Etgu F, Sekerlisoy Tatar G (2025). Risk factors and epidemiology of acne severity and acne scar development: a comprehensive clinical study. Dermatology Practical & Conceptual, 15(4), e20256108. https://doi.org/10.5826/dpc.1504a6108 PubMed
• Jacob CI, Dover JS, Kaminer MS (2001). Acne scarring: a classification system and review of treatment options. Journal of the American Academy of Dermatology, 45(1), 109–117. https://doi.org/10.1067/mjd.2001.113451 PubMed
• Wilson BB, Dent CH, Cooper PH (1990). Papular acne scars: a common cutaneous finding. Archives of Dermatology, 126(6), 797–800. PubMed
• Boen M, Jacob C (2019). A review and update of treatment options using the acne scar classification system. Dermatologic Surgery, 45(3), 411–422. https://doi.org/10.1097/DSS.0000000000001765 PubMed
• Zaleski-Larsen LA, Fabi SG, McGraw T, Taylor M (2016). Acne scar treatment: a multimodality approach tailored to scar type. Dermatologic Surgery, 42(Suppl 2), S139–S149. https://doi.org/10.1097/DSS.0000000000000746 PubMed
• Walsh LA, Wu E, Pontes D, et al. (2023). Keloid treatments: an evidence-based systematic review of recent advances. Systematic Reviews, 12(1), 42. https://doi.org/10.1186/s13643-023-02192-7 PubMed
• Elbuluk N, Grimes P, Chien A, et al. (2021). The pathogenesis and management of acne-induced post-inflammatory hyperpigmentation. American Journal of Clinical Dermatology, 22(6), 829–836. https://doi.org/10.1007/s40257-021-00633-4 PubMed
• Kalantari Y, Dadkhahfar S, Etesami I (2022). Post-acne erythema treatment: a systematic review of the literature. Journal of Cosmetic Dermatology, 21(4), 1379–1392. https://doi.org/10.1111/jocd.14804 PubMed
• Goodman GJ, Baron JA (2006). Postacne scarring: a qualitative global scarring grading system. Dermatologic Surgery, 32(12), 1458–1466. https://doi.org/10.1111/j.1524-4725.2006.32354.x PubMed
• Bhargava S, Cunha PR, Lee J, Kroumpouzos G (2018). Acne scarring management: systematic review and evaluation of the evidence. American Journal of Clinical Dermatology, 19(4), 459–477. https://doi.org/10.1007/s40257-018-0358-5 PubMed
• Dréno B, Bissonnette R, Gagné-Henley A, et al. (2018). Prevention and reduction of atrophic acne scars with adapalene 0.3%/benzoyl peroxide 2.5% gel in subjects with moderate or severe facial acne: results of a 6-month randomized, vehicle-controlled trial using intra-individual comparison. American Journal of Clinical Dermatology, 19(2), 275–286. https://doi.org/10.1007/s40257-018-0352-y PubMed
• Fatima S, Braunberger T, Mohammad TF, Kohli I, Hamzavi IH (2020). The role of sunscreen in melasma and postinflammatory hyperpigmentation. Indian Journal of Dermatology, 65(1), 5–10. https://doi.org/10.4103/ijd.IJD_295_18 PubMed
• Ahramiyanpour N, Rastaghi F, Parvar SY, et al. (2023). Subcision in acne scarring: a review of clinical trials. Journal of Cosmetic Dermatology, 22(3), 744–751. https://doi.org/10.1111/jocd.15480 PubMed
• Ptaszek B, Czernecka M, Podsiadło S (2025). The use of a fractional laser in acne scar treatment — a systematic review. Life, 15(6), 915. https://doi.org/10.3390/life15060915 PubMed
• Liu F, Zhou Q, Tao M, Shu L, Cao Y (2024). Efficacy and safety of CO2 fractional laser versus Er:YAG fractional laser in the treatment of atrophic acne scar: a meta-analysis and systematic review. Journal of Cosmetic Dermatology, 23(9), 2768–2778. https://doi.org/10.1111/jocd.16348 PubMed
• Sitohang IBS, Sirait SAP, Suryanegara J (2021). Microneedling in the treatment of atrophic scars: a systematic review of randomised controlled trials. International Wound Journal, 18(5), 577–585. https://doi.org/10.1111/iwj.13559 PubMed
• Mehrabi J, Shehadeh W, Gallo ES, Artzi O, Horovitz T (2023). Comparison of 2 hyaluronic acid-based fillers for the treatment of acne scars: structural lifting versus biostimulatory effect. Dermatologic Surgery, 49(6), 581–586. https://doi.org/10.1097/DSS.0000000000003789 PubMed
• Dayal S, Kaur R, Sahu P (2022). Efficacy of microneedling with 35% glycolic acid peels versus microneedling with 15% trichloroacetic acid peels in treatment of atrophic acne scars: a randomized controlled trial. Dermatologic Surgery, 48(11), 1203–1209. https://doi.org/10.1097/DSS.0000000000003556 PubMed
• Kang C, Lu D (2022). Combined effect of microneedling and platelet-rich plasma for the treatment of acne scars: a meta-analysis. Frontiers in Medicine, 8, 788754. https://doi.org/10.3389/fmed.2021.788754 PubMed
• Yan C, Phinyo P, Yogya Y, Chuamanochan M, Wanitphakdeedecha R (2025). Risk factors associated with facial acne scarring in Thai patients with acne: a cross-sectional study. Journal of Cosmetic Dermatology, 24(1), e16695. https://doi.org/10.1111/jocd.16695 PubMed
• Tan J, Beissert S, Cook-Bolden F, et al. (2022). Impact of facial atrophic acne scars on quality of life: a multi-country population-based survey. American Journal of Clinical Dermatology, 23(1), 115–123. https://doi.org/10.1007/s40257-021-00628-1 PubMed