Background: Retinol, a precursor of retinoic acid, has great potentials as a topical anti-aging molecule; however, only a handful of clinical investigations have been published to date.
Objective: This study aimed to assess the efficacy and safety of 0.1% stabilized retinol on photodamaged skin during a one-year treatment.
Methods: The investigation included two 52-week, double-blind, vehicle-controlled studies. In the main study, 62 subjects applied either a stabilized retinol formulation or its vehicle to the full face. A second exploratory study evaluated histological/histochemical markers in 12 subjects after 52 weeks of either retinol or vehicle use on contralateral dorsal forearms.
Results: The retinol group showed significant photodamage improvement over vehicle at all timepoints during the study. After 52 weeks, retinol had improved crow's feet fine lines by 44%, and mottled pigmentation by 84%, with over 50% of subjects showing +2 grades of improvement in many parameters. Additionally, at week 52, histochemical data confirmed the clinical results, showing increased expression of type I procollagen, hyaluronan, and Ki67 as compared to vehicle.
Conclusion: This study confirms that a stabilized retinol (0.1%) formulation can significantly improve the signs of photoaging, and improvements in photodamage continue with prolonged use.