Thiamidol

Introduction

What is thiamidol?

Thiamidol or isobutylamido thiazolyl resorcinol is a skin lightening agent. It was identified by the German company Beiersdorf through first screening 50,000 compounds for inhibitors of human tyrosinase, the rate-limiting enzyme in melanin production, and then optimising the lead compound to develop a derivative with properties compatible with topical formulations (R).

Efficacy

Outcome	Grade	Effect	Evidence	Studies
Hyperpigmentation	B	🠫 Slight	★★★ Fair	4 studies 187 participants
Melasma	B	🠫 Slight	★★★ Fair	2 studies 91 participants
Skin Barrier Function	E	– No Effect	★★ Some	1 study 60 participants
Skin Brightness	E	– No Effect	★★ Some	1 study 48 participants

Mechanisms

Outcome				Grade		Effect		Evidence		Studies
Tyrosinase				D		🠫🠫🠫 Marked		★ Basic		1 study
Melanin				E		– No Effect		★★ Some		2 studies 60 participants

Side Effects

Outcome			Effect		Frequency			Studies
Itching			⇧ Increase		—			3 studies
Skin Redness			⇧ Increase		4% (3 out of 69 participants)			3 studies

Latest Research

What is thiamidol?

Efficacy of isobutylamido thiazolyl resorcinol for prevention of laser-induced post-inflammatory hyperpigmentation: A randomized, controlled trial (2024)

Efficacy and safety of a novel triple combination cream compared to Kligman's trio for melasma: A 24-week double-blind prospective randomized controlled trial (2023)

Thiamidol® in moderate-to-severe melasma: 24-week, randomized, double-blind, vehicle-controlled clinical study with subsequent regression phase (2021)

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 (2021)

Efficacy and safety of topical isobutylamido thiazolyl resorcinol (Thiamidol) vs. 4% hydroquinone cream for facial melasma: an evaluator-blinded, randomized controlled trial (2021)