Acne Scars and Keloids — Cosmetic Ingredients That Support Skin Repair

Acne scars — more than just an aesthetic issue

Once active acne lesions clear up, they often leave marks behind — from flat discoloration to deep atrophic scars. For many people, these marks are a bigger problem than the acne itself, affecting self-esteem and quality of life. The good news: the right cosmetic ingredients can support the skin's repair process. The bad news: it takes patience — a realistic timeline is 6-12 months of consistent care.

Note: This article focuses on cosmetic ingredients that improve the appearance of post-acne skin. Deep atrophic scars and keloids require dermatological intervention — laser treatments, microneedling, injections. Consult a dermatologist to choose the best approach for you.

PIH vs PIE — two types of post-acne discoloration

Before you reach for any product, you need to know which type of mark you're dealing with. This is crucial, because different types of discoloration respond to different ingredients.

PIH — Post-Inflammatory Hyperpigmentation

PIH appears as brown or dark-brown spots caused by excess melanin production in response to inflammation. It's more common in people with darker skin tones (Fitzpatrick phototypes III-VI). The melanin deposits in either the epidermis or the dermis.

PIH responds to brightening ingredients and those that speed up epidermal renewal — vitamin C, niacinamide, azelaic acid, arbutin and AHAs.

PIE — Post-Inflammatory Erythema

PIE shows up as red or pink spots resulting from damaged and dilated blood vessels at the site of inflammation. It's more common in people with fair skin (phototypes I-III). A simple diagnostic test: press on it with a glass slide — PIE blanches under pressure, PIH does not.

PIE is harder to treat with cosmetics. It responds partly to niacinamide and azelaic acid, but often requires vascular treatments (laser, IPL).

Cosmetic ingredients for tackling scars and discoloration

Vitamin C (L-ascorbic acid)

Vitamin C is one of the most thoroughly researched brightening ingredients. In cosmetics it acts as an antioxidant and inhibits tyrosinase, the key enzyme in melanin production. It's especially effective at reducing PIH.

The most active form is L-ascorbic acid at a concentration of 10-20%, at a pH below 3.5. More stable derivatives (ascorbyl glucoside, sodium ascorbyl phosphate) are gentler but work more slowly. Vitamin C also supports collagen synthesis, which has a beneficial effect on scar structure.

Niacinamide (vitamin B3)

Niacinamide at a concentration of 4-5% reduces the transfer of melanosomes to keratinocytes, which leads to a reduction in discoloration. At the same time, it strengthens the skin barrier and helps calm inflammation. It works on both PIH and — to some extent — PIE (thanks to its vessel-strengthening properties). It's very well tolerated and can be combined with most active ingredients.

Retinol (vitamin A)

Retinol is one of the most important ingredients in caring for acne scars. Its role is multi-directional:

• Stimulating cell renewal — it speeds up the keratinocyte cycle, helping to "push out" melanin from the epidermis
• Stimulating collagen synthesis (collagen remodeling) — it improves the structure and fills out atrophic scars
• Normalizing keratinization — it evens out skin texture

Retinol requires patience — results appear after 8-12 weeks of regular use. Start with a low concentration (0.1-0.3%) and increase it gradually to minimize irritation. Always apply SPF during the day.

AHAs — gentle exfoliation

Alpha-hydroxy acids — especially glycolic acid and lactic acid — speed up the shedding of dead skin cells, revealing the brighter skin underneath. In addition, glycolic acid at concentrations of 5-10% stimulates collagen synthesis in the dermis.

AHAs help reduce PIH and improve skin texture. Use them 2-3 times a week rather than daily, to avoid over-exfoliating. Lactic acid is gentler and better tolerated by sensitive skin.

Silicones — the gold standard in scar care

Silicone sheets and gels are considered the gold standard in non-invasive scar care — by both dermatologists and plastic surgeons. Their mechanism of action is based on:

• Occlusion — maintaining optimal hydration of the scar tissue
• Regulating collagen synthesis — normalizing the healing process
• Protection from external factors

Silicone sheets should be worn for a minimum of 12 hours a day for at least 2-3 months. Silicone gels are a more convenient alternative — they're applied twice a day once dry. Silicones are particularly effective for hypertrophic scars and keloids — they prevent them from growing.

A realistic timeline for results

One of the most common sources of disappointment is expecting fast results. Here's a realistic timeline:

• 4-6 weeks — first subtle changes in the color of PIH
• 2-3 months — noticeable improvement in discoloration, early results from retinol
• 6 months — significant reduction in PIH, visible improvement in texture with retinol
• 12 months — the maximum results achievable with cosmetics, clear improvement in shallow scars

PIE fades more slowly than PIH — taking up to 12-18 months, partly on its own and partly with the support of vessel-strengthening ingredients.

Sun protection — an absolute must

UV makes every type of post-acne discoloration worse. PIH darkens with sun exposure, and PIE can become permanent. Without daily use of SPF 30+, all your skincare efforts are pointless. Apply sunscreen every day, even in winter, even at home near a window.

When cosmetics aren't enough

Cosmetic ingredients help reduce flat discoloration and shallow irregularities. However, deep atrophic scars (icepick, boxcar, rolling) and keloids require dermatological intervention — laser treatments (fractional CO2, Er:YAG), microneedling, trichloroacetic acid (TCA cross), or filler or corticosteroid injections.

Consult a dermatologist, who will assess the type of scarring and choose the best treatment. Cosmetic care will be a valuable complement to professional procedures.

Analyze the formulas of brightening and repair products in the PurScore search engine. Browse our ingredient database to understand how each active ingredient works. You'll find more tips in our guide to caring for sensitive skin.