In line with the observation that "You can tell how old someone is by looking at their neck", the neck is where wrinkles become obvious as people age. Thus, while neck wrinkles are an important factor in determining how old someone looks, in the field of functional cosmetics there have been almost no reports on agents that can treat neck wrinkles effectively. Based on the exacting guidelines of Japanese Cosmetic Science Society for evaluation of anti-wrinkle products, in a randomized placebo-controlled double-blinded study, we demonstrated that retinol(RO) is remarkably effective in improving wrinkles in the outer corner of the eyes. After a rigorous examination, RO, which we developed as a cosmetic ingredient, was approved by the Japanese Ministry of Health, Labour and Welfare in 2017 as an active ingredient that "improves wrinkles" in quasi-drugs. Recently, we conducted clinical trials not only for wrinkles around the eyes but also for neck wrinkles and evaluated the RO's effectiveness.
The severity of neck wrinkles in about 152 Japanese female subjects was carefully assessed. In 84 subjects selected from the 152 who were assessed, the RO formulation(RF) or the RO-extracted placebo formulation(PF) was continuously applied for 12 weeks twice a day to both the face and the neck. During the application, we evaluated changes in skin condition by visual assessment(VA) and instrument analysis(IA) every four weeks.
We classified skin condition according to our unique neck wrinkle grading standard, which consists of 11 levels. Using this grading standard, the severity of neck wrinkles was found to correlate with age based on VA of the neck wrinkles of 152 subjects.
It was found that compared to PF, the RF significantly improved neck wrinkles following application for 8 weeks, thus demonstrating the effectiveness of RF based on both VA and IA. Furthermore, the results of noninvasive ultrasonic image analysis suggest that RO markedly increased the extracellular matrix component(ECM) of the dermis.
In conclusion, our designed clinical study showed that RO had an outstanding improvement effect not only on the crow’s feet but also on neck wrinkles, as they claim it also increased the ECM.

Retinol remarkably effective in reducing neck wrinkles