Shiseido recently described findings that pure retinol (vitamin A)a provides anti-wrinkle efficacy through a new function: skin softening. This effect prevents the progression of wrinkles from the surface of the skin to its deeper layers.
Using its internal and external skin elasticity 3D imaging system,b Shiseido confirmed that the hardening of the stratum corneum increases mechanical stress applied to the dermis when the skin moves with facial expressions, etc. According to the company, this leads to the progression of the gap between the stratum corneum and dermis — the root cause of wrinkles.
A continuous use study was then conducted to evaluate changes in the hardness of the stratum corneum when subjects applied a cream containing pure retinol to one side of the face for 12 weeks. The panel included 35 healthy Japanese women with shallow to slightly deep wrinkles in the outer corner of the eyes.
Results showed the stratum corneum was significantly softer after four weeks of continuous use, compared with baseline. Moreover, with continued use, the softness of the stratum corneum was maintained, with a consequent reduction in the area of wrinkles.
Shiseido emphasized that while pure retinol is highly effective in improving skin, it is easily degraded by oxygen, heat, light, etc. The company used is Retinol TripleLock Technology to stabilize the ingredient and ensure it was delivered to the skin to fully demonstrate effects.
The company presented the results of this research at the 48th Convention of the Japanese Cosmetic Science Society on Jun. 23, 2023, and parts of this research during the 31st International Federation of Societies of Cosmetic Chemists (IFSCC) Congress 2020, held digitally and in Yokohama.
a Per Shiseido, pure vitamin A and not a derivative; reportedly, Shiseido is the only company in Japan approved to blend in pure retinol (vitamin A) as a quasi-drug active ingredient
b Patented technology jointly developed by Shiseido, Honda Electronics Co., Ltd., and Toyohashi University of Technology; the technology converts the reflected ultrasonic signals from the inside of the skin into the modulus of elasticity