Combining a thiamidol-based serum with laser therapy is more effective at fading dark spots than laser treatment alone, a new study suggests,
The study was selected as a late breaker top five finalist for the best poster Akamai Award at 2025 Maui Derm Hawaii meeting.
Thiamidol (isobutylamido thiazolyl resorcinol) is a novel human tyrosinase inhibitor recently shown to be effective in treating hyperpigmentation.
For the study, 24 patients with symmetrical facial hyperpigmentation were treated with five sessions of low-fluence Q-switched Nd:YAG 1064-nm laser therapy once weekly on the whole face. One side of their face was randomly treated with a thiamidol-based serum formulation, and the other was treated with a placebo cream for 12 weeks.
Patients were followed for eight weeks after their last laser treatment. Researchers recorded the relative lightness index (RL*I), Facial Hyperpigmentation Severity Score on the Malar Area (FHSSm), patient satisfaction, recurrence, and adverse events.
The main takeaway? Both sides of patients’ faces demonstrated significant reductions of mean RL*I and mean FHSSm from baseline. In the fourth week, the thiamidol-based serum-treated side showed more improvement in mean RL*I than the placebo-treated side (62.5% vs. 47.3% improvement. The mean FHSSm on the Thiamidol-based serum treated was reduced at a significantly higher percentage than the placebo-treated side (54.4% vs 40.2% reduction). Partial recurrence was observed on both sides. No serious side effects were noted.
“Combined thiamidol-based serum and LFQS therapy was more superior than LFQS monotherapy in treating facial hyperpigmentation,” the study authors conclude. “Thiamidol-based formulations may serve as adjuvant treatment for patients with hyperpigmentation with standard therapy.”
