Longer follow-up must show whether faster early healing leads to shallower scars at 3 to 6 months. It must also show whether redness and brown pigment stay lower over months, not just at Day 14. Atrophic scars are indented scars left after acne heals.
In January 2026, investigators tested 15% vitamin C plus 1% vitamin E plus 0.5% ferulic acid serum against saline right after ablative fractional CO2 laser. Fractional CO2 treats scars by removing tiny columns of damaged skin and starting new collagen growth. The early results looked better for healing, but scar remodeling takes months.
Medical information disclaimer: This article is for general educational purposes only and does not provide medical advice, diagnosis, or treatment. Always consult a physician or other qualified health professional about symptoms, medications, tests, or treatment decisions.
Table of Contents
- What the January 2026 split-face trial tested
- Why two weeks cannot prove scar remodeling
- What scar improvement must be measured at 3 to 6 months
- Which side effects longer studies must track
What the January 2026 split-face trial tested
Adults with atrophic acne scars received laser on both cheeks, then antioxidant serum on one cheek and normal saline on the other cheek. The design compared healing on opposite sides of the same face, according to the trial report published in the Journal of Cosmetic Dermatology the split-face trial report.
The antioxidant-treated side healed faster and held water better during early recovery. It also showed lower redness and melanin readings and better-preserved barrier function, according to the PubMed record for the 2026 Journal of Cosmetic Dermatology trial the trial summary. Those are recovery measures, not proof of flatter scars.
Why two weeks cannot prove scar remodeling
Formal follow-up ended at Day 14, with checks at 30 minutes and Days 3, 7, and 14. That window captures crusting, swelling, redness, and early barrier repair. It cannot prove lasting collagen remodeling or late dark spots.
That timing matters because fractional CO2 works by vaporizing fragmented collagen and triggering new collagen formation over months. The people affected include adolescents and adults with moderate-to-severe rolling, boxcar, and icepick scars, as described in a Facial Plastic Surgery review from Thieme. A reader should view Day 14 gains as a promising start, not a final scar result.
What scar improvement must be measured at 3 to 6 months
Longer studies must score scar depth and texture with accepted tools such as Goodman and Baron quantitative scores, ECCA, or Scar Global Assessment. Scores should be checked at 3 to 6 months, when collagen increases and treatment effects become clearer.
Practical Dermatology reports ECCA improvements of roughly 25 to 45% after fractional laser in its evidence update the laser evidence review. Ask for the same scar scale, same lighting, and same camera angle at each visit. Useful records include: This makes it easier to tell whether added serum changed depth or only eased the first two weeks.
- baseline scar subtype and severity score before laser
- repeat score at 3 months and again at 6 months
- close-up photos of rolling, boxcar, and icepick areas
- notes on sun protection, retinoids, and pick or peel habits
Which side effects longer studies must track
Longer follow-up must track persistent redness lasting days to weeks, crusting, swelling, acne flare, and post-inflammatory darkening. One tertiary-center retrospective found post-inflammatory hyperpigmentation in 59.5% of cases, with higher risk in darker skin and with higher energy, according to the hospital study summarized on Paperity the side-effect retrospective.
That risk profile limits what the small January 2026 trial can prove. The Wiley version of the report describes a limited Chinese patient sample and saline control, so general dosing, sun-protection adherence, skin-tone effects, and added benefit for final scar depth need larger multicenter trials. Until then, ask your dermatologist how they set energy for your skin tone and how they will watch pigment at 1, 3, and 6 months.
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