Author(s)

Amaryllis Aganahi¹, Richard Parker¹, Yohei Tanaka²

¹RATIONALE, Kyneton, Australia.
²Clinica Tanaka Plastic, Reconstructive Surgery and Anti-Aging Center, Matsumoto, Japan.

Background: Continuous hydration is one of the essential factors in maintaining skin health. Despite the knowledge that skin hydration is essential for all major skin protection and repair processes, and the widespread prevalence of moisturizers, skin dryness continues to present an ongoing problem to skin health, with solar skin damage being a major cause of surface dryness and deeper moisture loss. Objective: To evaluate the skin hydration effectiveness of a comprehensive skincare regimen embracing both daily solar protection from ultraviolet through to near-infrared radiation and nightly solar repair in Fitzpatrick skin types I to IV. Materials and methods: Multiple studies were performed on a 3-dimensional human skin model composed of keratinocytes and fibroblasts and in-vivo on patients with Fitzpatrick skin types from I to IV. Solar specific topical skincare formulations (The Essential Six, RATIONALE, Victoria, Australia) were assessed. In-vivo studies ran from 28 days to 12 weeks and multiple skin assessments have been performed before and after using the formulations. Results: The results presented in this paper confirm a potential link between increased skin hydration and radiance via a mechanism of preventing and repairing solar skin damage. By addressing both the prevention and repair of sun damage, increased levels of hydration as well as skin barrier function maintenance are observed to correlate to increased skin radiance. Conclusion: The results of this study indicate that the specific solar skincare formulations, focused on the daily solar protection and nightly repair of photodamage provide a safe and highly effective pathway to increased skin hydration and rejuvenation.

Hydration, Photoprotection, Rejuvenation, Skin Hydration, Sunscreen

Aganahi, A. , Parker, R. and Tanaka, Y. (2025) Skin Hydration Augmentation Following Solar Protective and Repair Skincare Regimen. Journal of Cosmetics, Dermatological Sciences and Applications, 15, 1-23. doi: 10.4236/jcdsa.2025.151001.