The Day the Common Knowledge of Serums Changes: Vitamin C Also Reconstructs Barrier Functions - Increasing Skin Thickness and Offering Anti-Aging Benefits!

Introduction ― The "Vitamin C Reversal" That Shook the Skincare World

"The thinning of the epidermis with age is inevitable"—a belief long held as common knowledge, has been overturned by a Japanese research team. A recent report by the Tokyo Metropolitan Institute of Gerontology and other institutions demonstrated that Vitamin C (L-ascorbic acid) can "reset the genetic switch" and visibly thicken a human epidermis model. The study has been reported by InfoMoney and O Globo, sparking both support and criticism on social media.infomoney.com.broglobo.globo.com

Research Design

• Model: 3D human epidermal tissue (air-exposed type).

• Concentration: Vitamin C 0.1 mM / 1 mM (equivalent to levels actually delivered to the skin from the bloodstream).

• Observation Period: 7 days, 14 days.

• Evaluation Metrics: Epidermal thickness, stratum corneum thickness, keratinocyte proliferation markers (Ki-67, etc.), DNA methylation rate.

As a result, on the 7th day, the viable cell layer significantly increased by 15–20%, and by the 14th day, the stratum corneum became thinner, suggesting normalization of turnover.infomoney.com.br

The Key to Gene Expression is "DNA Demethylation"

Vitamin C activates TET enzymes as a cofactor, removing methyl groups and reactivating dormant proliferation-related genes (such as KRT14, DSG3). This overlaps with the mechanism of enhancing the self-renewal capacity of epidermal stem cells. It aligns with the previously reported "collagen synthesis promotion effect" in SciELO, potentially reinforcing the three-dimensional structure of the dermal-epidermal junction (DEJ).scielo.br

Social Media Reactions ― Between Enthusiasm and Caution

Potential and Challenges of Clinical Application

1. Countermeasures for Skin Thinning in the Elderly and Diabetic Patients
   Potential for application in reducing keratinization disorders and pressure ulcer risks.

2. In Tandem with Whitening and Photoaging Care
   Inhibition of melanin transfer and UV damage is known. Thickening of the epidermis further enhances barrier function.

3. Transdermal Absorption and Formulation Design
   Limited penetration in its water-soluble form—lipid-soluble derivatives (SAP, MAP) or liposomal formulations are essential.dermaclub.com.br

4. Safety and Irritation
   High-concentration solutions with a pH around 3 have reports of "tingling" and "redness." Stabilization with Vitamin E/Ferulic Acid can mitigate irritation.

Expert Comments

• Akihito Ishigami, PhD (Lead Author of the Study)
  "The novelty lies in rejuvenating keratinocytes through DNA demethylation."oglobo.globo.com

• Chiaki Fujita, Dermatologist(Interview Comment)
  "Adding epidermal regeneration to the traditional approach focused on dermal collagen is significant in clinical practice. However, long-term clinical trials are yet to come."

Usage Guide (Recommended Protocol)

Note: Use within 3 months of opening / Store in a dark place. Reduce to twice a week if irritation occurs.