PoreWise Skin concern
Acne marks and scars
Primary sourceAcne marks and scars: the marks left after a breakout heals — most often post-inflammatory hyperpigmentation (PIH) or redness (PIE) in deeper skin tones, and, in some cases, true atrophic or raised scars. Skincare can address the pigment and redness type; true atrophic or raised scars need clinic procedures. The strongest evidence comes from a 2024 human trial: In 72 people with mild-to-moderate acne, a 15% azelaic acid gel reduced post-inflammatory erythema (PAHPI) significantly more than placebo at weeks 8 and 12, and lowered melanin content in post-inflammatory hyperpigmentation lesions at week 12. 1 ingredient has evidence for Acne marks and scars: Azelaic acid.
These two trials measured pigment and redness after acne: 2024 · 72 people · mild-to-moderate acne · PMID 38734843; 2024 · 28 people · acne-induced PIH · PMID 38638185.
Where the definition comes from
Source wording
“Postinflammatory hyperpigmentation (PIH) commonly occurs after various endogenous and exogenous stimuli, especially in dark-skinned individuals … The depth of melanin pigment is the key factor to predict prognosis.” — Silpa-Archa et al., J Am Acad Dermatol 2017 (PMID 28917451).
Postinflammatory hyperpigmentation: A comprehensive overview: Epidemiology, pathogenesis, clinical presentation, and noninvasive assessment technique Journal of the American Academy of Dermatology (Silpa-Archa N)
Ingredients at a glance
2024 · 72 people · patients with mild-to-moderate acne (60 completed) · PMID 38734843
| Ingredient | Measured outcome | Based on | Certainty | Year |
|---|---|---|---|---|
| Azelaic acid | Skin effect | Human trial | High | 2024 |
| — | Skin effect | Human trial | Moderate | 2024 |
Studies and results
- Effects of 15% Azelaic Acid Gel in the Management of Post-Inflammatory Erythema and Post-Inflammatory Hyperpigmentation in Acne Vulgaris
In 72 people with mild-to-moderate acne, a 15% azelaic acid gel reduced post-inflammatory erythema (PAHPI) significantly more than placebo at weeks 8 and 12, and lowered melanin content in post-inflammatory hyperpigmentation lesions at week 12.
Human trial · 2024 · 72 people · patients with mild-to-moderate acne (60 completed) · People with mild-to-moderate acne and acne-induced post-inflammatory erythema or hyperpigmentation, applying the gel twice daily for 12 weeks. · PIH lesion counts improved from baseline in both groups; the significant between-group difference was in PAHPI and melanin content.
Study limits
Study conditions and measured outcomes.
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Azelaic acid Human trial · 2024
PIH lesion counts improved from baseline in both groups; the significant between-group difference was in PAHPI and melanin content.
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ev-acne-marks-cysteamine-rct Human trial · 2024
The comparison treatment contains hydroquinone, a drug ingredient; small sample (28 completed).
Products with a basis for this
2 products · 10% Azelaic Acid Booster · Azelaic Acid 10% + Hyaluron Redness Soothing Serum · 2024 · 72 people · patients with mild-to-moderate acne (60 completed) · PMID 38734843
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Paula's Choice
10% Azelaic Acid Booster
- Azelaic acid 1 finding
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Anua
Azelaic Acid 10% + Hyaluron Redness Soothing Serum
- Azelaic acid 1 finding
Research-backed approaches
These studies measured finished products and whole routines.
- 1 Skin effectAssessing the Effectiveness of Stabilized Cysteamine 5% Cream Compared to Hydroquinone 4%/Ascorbic Acid 3% Combination Cream in Treating Acne-induced Post-inflammatory Hyperpigmentation: A Randomized, Controlled Study
In 28 people with acne-induced post-inflammatory hyperpigmentation, both a 5% stabilised cysteamine cream and a 4% hydroquinone/3% ascorbic acid cream significantly reduced PAHPI scores and melanin index over 4 months, with similar values between treatments.
Human trial · 2024 · 28 people · enrolled, 28 completed, with acne-induced PIH · People with acne-induced post-inflammatory hyperpigmentation, treated for 4 months. · The comparison treatment contains hydroquinone, a drug ingredient; small sample (28 completed).
Common questions
- Which ingredients have been studied for Acne marks and scars?
- Ingredients with evidence for Acne marks and scars: Azelaic acid.
- How many people were studied?
- 2 findings · 2024 · 72 people · patients with mild-to-moderate acne (60 completed) · PMID 38734843
- What can I use for Acne marks and scars?
- Azelaic acid · 2024 · 72 people · patients with mild-to-moderate acne (60 completed) · PMID 38734843
- Can I use these every day for Acne marks and scars?
- People with mild-to-moderate acne and acne-induced post-inflammatory erythema or hyperpigmentation, applying the gel twice daily for 12 weeks（2024 · 72 participants · 72 patients with mild-to-moderate acne (60 completed) · PMID 38734843）