Clinical Efficacy of a 12% Pure Vitamin C Serum Across All Skin Phototypes: An Integrated In Vitro-In Vivo Evaluation

Skin aging is associated with loss of collagen network qualitative and quantitative integrity, which are crucial for skin structure and function. Topical application of pure vitamin C (L-ascorbic acid) may alleviate signs of skin aging (e.g., wrinkles, lack of firmness). The objectives of this open-label, monocentric study were to determine whether topical treatment with a dermocosmetic serum containing a high concentration (12%) of pure vitamin C (PVC12 serum) could increase epidermal thickness and positively influence collagen fiber synthesis and organization, thus alleviating visible signs of skin aging.

This study investigated the efficacy and tolerability of PVC12 serum over 3 months compared with baseline. Healthy participants aged ≥18 years with any skin phototype received twice-daily treatment with the PVC12 serum. Evaluations included reflectance confocal microscopy measures and instrumental measures of skin firmness and elasticity, as well as clinical scoring of multiple skin aging signs.

The study included 49 women (skin phototypes I-VI). After 84 days of continuous use of PVC12 serum, epidermal thickness was significantly increased by 16.4% compared with baseline. More than half of the participants showed improvements in total collagen score and cross-linked collagen fibers. A significant decrease in coarse and curled collagen fibers was also observed. There was significant improvement in skin firmness and elasticity throughout the study. At the end of treatment, there were significant and clinically relevant improvements in various parameters (e.g., radiance, skin oiliness, pores). The treatment was well tolerated, with no occurrence of treatment-related adverse events.

PVC12 serum may exert beneficial effects on skin of all phototypes, including improved skin thickness, collagen fiber synthesis and quality, skin firmness and elasticity, and other parameters. This evidence supports the effectiveness and tolerability of pure vitamin C in the prevention and correction of skin aging signs over time.