Real‐world evidence for the efficacy and tolerability of an isobutylamido‐thiazolyl‐resorcinol (Thiamidol)‐containing skincare regimen on facial hyperpigmentation and overall skin appearance: A multi‐centre study in 11 European countries

Objective Hyperpigmentation is a common skin concern that can significantly impact the quality of life of affected individuals. Managing hyperpigmentation can be challenging due to its recurrent nature, side effects of available treatment options and multiple underlying biological mechanisms contributing to pigment formation and persistence. The tyrosinase inhibitor isobutylamido‐thiazolyl‐resorcinol (Thiamidol) has proven promising efficacy and safety in several controlled trials. This study sought to evaluate the real‐life efficacy and tolerability of thiamidol in an international patient population under real‐life conditions. Methods A multi‐national, multi‐centre, uncontrolled, open‐label study was conducted in 11 European countries. Participants with facial hyperpigmentation were recruited by dermatologists and applied a skincare regimen containing Thiamidol for 12 weeks. Expert assessments were conducted by dermatologists at baseline and after 2, 4, 8 and 12 weeks of application, evaluating parameters such as skin evenness, radiance, smoothness and the modified Melasma Area and Severity Index (mMASI). Additionally, self‐assessment by participants was conducted using standardized questionnaires. Statistical analysis was performed to assess relative changes in the examined parameters compared to baseline. Results A total of 629 participants completed the study (97,8% women, mean age 47 years, phototypes I–V). Expert grading revealed significant improvements in skin evenness, radiance and smoothness at all time points compared to baseline (all p < 0.05). After 12 weeks, a relative improvement of 91% in skin evenness, 82% in skin radiance and 73% in skin smoothness was observed. The mMASI score decreased significantly, with a reduction of −76% after 12 weeks. Overall, improvement of skin condition and tolerability were rated ‘very good’ in 70.1% and 81.1% of participants, respectively, by their treating dermatologist. Self‐assessment confirmed significant improvements in skin hyperpigmentation, evenness, radiance and smoothness, with 97% of participants expressing satisfaction with the Thiamidol‐containing skin‐care regimen and a desire to continue use. Conclusion This real‐life study demonstrates the efficacy and tolerability of a Thiamidol‐based skincare regimen in managing facial hyperpigmentation. Significant improvements observed in both expert assessments and self‐assessment as well as the very good tolerability highlight Thiamidol as a safe and effective cosmetic solution for hyperpigmentation.