Thiamidol containing treatment regimens in facial hyperpigmentation: An international multi‐centre approach consisting of a double‐blind, controlled, split‐face study and of an open‐label, real‐world study

Abstract

OBJECTIVE: Tyrosinase is the rate-limiting enzyme in melanogenesis. Thiamidol is the most potent inhibitor of human tyrosinase out of 50 000 tested compounds. In clinical studies, it was shown to improve facial hyperpigmentation, post-inflammatory hyperpigmentation and age spots significantly. To identify the optimal number of daily Thiamidol applications, we conducted a split-face study comparing the efficacy and tolerability of four-times with two-times daily application. Subsequently, we evaluated the efficacy and tolerability of a typical face care regimen containing Thiamidol in a real-world study. METHODS: The split-face study was double-blind, randomized, controlled, including two Thiamidol containing products (serum and day care SPF 30). The serum was applied twice daily on one half of the face and the day care SPF30 twice-daily on the whole face. The real-world study was open-label, observational, including three Thiamidol containing products (day care SPF 30 in the morning, serum and night care in the evening). In both studies, subjects with mild-to-moderate facial hyperpigmentation applied the products over 12 weeks. Assessments included clinical and subjective grading of hyperpigmentation, skin condition, hemi-/modified MASI, chromameter and clinical photography. RESULTS: In the split-face study (n = 34), hyperpigmentation, skin roughness and hMASI improved all significantly (P < 0.001) versus baseline, with first visible results after two weeks of twice-daily application. The four-times daily application led to significant improvement versus the two-times daily application. In the real-world study (n = 83), all evaluated parameters, including skin condition and chromametry (n = 30), improved significantly (P < 0.001) in comparison with baseline and the corresponding preceding visits. The subjects judged the cosmetic properties of the products positively. In both studies, the products were well tolerated. CONCLUSION: Four-times daily Thiamidol improves facial hyperpigmentation significantly more than two-times daily and is well tolerated by the subjects. The real-world study with a typical face care regimen containing Thiamidol shows improvement of facial hyperpigmentation and confirms tolerability. Furthermore, the data provide evidence for the suitability of this three-product Thiamidol regimen for day-today life.

Efficacy and safety of 0.15% isobutylamido thiazolyl resorcinol combined with hyaluronic acid vs 0.15% isobutylamido thiazolyl resorcinol or hyaluronic acid alone in melasma treatment: A randomized evaluator‐blind trial

“…Conventional first‐line treatments are primarily limited to tyrosinase inhibitors. Resorcinol is a well‐known tyrosinase inhibitor; several of its derivatives are currently being used to treat melasma, such as 4‐n‐butylresorcinol and thiazolyl resorcinols 22‐24 . The most recent pathological findings have clarified the interactions among keratinocytes, dermal fibroblasts, mast cells, vascularization, basement membrane disruption, many signaling pathways, and reactive oxygen species; they are also involved in the upregulation of tyrosinase 2 .…”

The top 10 cosmeceuticals for facial hyperpigmentation

“…6 A split-face double blind randomized controlled trial in 34 patients used two thiamidol containing products twice or four times daily on one half of the face and SPF30 on the whole face. 6 The second trial was a separate single-arm observational study (n = 83) in which patients were treated with SPF30 in the day and at night thiamidol serum and night care cream. 6 At 12-weeks, hyperpigmentation, skin roughness and MASI all improved significantly compared with baseline (−0.78 ± 0.52, −0.87 ± 0.45; P < .001) in the split-face study, whilst in the observational real-life study, skin condition and chromametry improved significantly compared to baseline.…”

“…A separate study investigated the use of thiamidol in two different trials 6 . A split‐face double blind randomized controlled trial in 34 patients used two thiamidol containing products twice or four times daily on one half of the face and SPF30 on the whole face 6 .…”

“…A separate study investigated the use of thiamidol in two different trials 6 . A split‐face double blind randomized controlled trial in 34 patients used two thiamidol containing products twice or four times daily on one half of the face and SPF30 on the whole face 6 . The second trial was a separate single‐arm observational study ( n = 83) in which patients were treated with SPF30 in the day and at night thiamidol serum and night care cream 6 .…”

“…Self‐assessment scores also improved significantly from baseline. The four‐times daily thiamidol regimen improved facial hyperpigmentation significantly more than the two‐times group and was well‐tolerated 6 . More extensive randomized clinical trials that also include males, with post‐study follow‐ups following cessation of treatment are required 5 …”