Summary Background Very few over-the-counter cosmetic ‘anti-ageing’ products have been subjected to a rigorous double-blind, vehicle-controlled trial of efficacy. Previously we have shown that application of a cosmetic ‘anti-ageing’ product to photoaged skin under occlusion for 12 days can stimulate the deposition of fibrillin-1. This observation infers potential to repair and perhaps clinically improve photoaged skin.
Objective We examined another similar over-the-counter cosmetic ‘anti-ageing’ product using both the patch test assay and a 6-month double-blind, randomized controlled trial (RCT), with a further 6-month open phase to assess clinical efficacy in photoaged skin.
Methods For the patch test, a commercially available test product and its vehicle were applied occluded for 12 days to photoaged forearm skin (n = 10) prior to biopsy and immunohistochemical assessment of fibrillin-1; all-trans retinoic acid (RA) was used as a positive control. Sixty photoaged subjects were recruited to the RCT (test product, n = 30 vs. vehicle, n = 30; once daily for 6 months, face and hands) with clinical assessments performed at recruitment and following 1, 3 and 6 months of use. Twenty-eight volunteers had skin biopsies (dorsal wrist) at baseline and at 6 months treatment for immunohistochemical assessment of fibrillin-1 (test product, n = 15; vehicle, n = 13). All volunteers received the test product for a further 6 months. Final clinical assessments were performed at the end of this open period.
Results In the 12-day patch test assay, we observed significant immunohistological deposition of fibrillin-1 in skin treated with the test product and RA compared with the untreated baseline (P = 0·005 and 0·015, respectively). In the clinical RCT, at 6 months, the test product produced statistically significant improvement in facial wrinkles as compared to baseline assessment (P = 0·013), whereas vehicle-treated skin was not significantly improved (P = 0·11). After 12 months, there was a significant benefit of the test product over that projected for the vehicle (70% vs. 33% of subjects improving; combined Wilcoxon rank tests, P = 0·026). There was significant deposition of fibrillin-1 in skin treated for 6 months with the test product [(mean ± SE) vehicle 1·84 ± 0·23; test product 2·57 ± 0·19; ancovaP = 0·019).
Conclusions In a double-blind RCT, an over-the-counter cosmetic ‘anti-ageing’ product resulted in significant clinical improvement in facial wrinkles, which was associated with fibrillin-1 deposition in treated skin. This study demonstrates that a cosmetic product can produce significant improvement in the appearance of wrinkles and further supports the use of fibrillin-1 as a robust biomarker for the repair of photoaged dermis.