The present invention relates to the identification of the glycogen synthase kinase-3 beta (GSK3B or GSK-3P) as a therapeutic target of pigmentation disorder and as biomarker of pigmentation status. The invention in particular relates to products and methods for treating a hypopigmentation disorder. The invention also relates to products and methods for detecting, diagnosing, staging or monitoring the course of hypopigmentation disorder and is particularly suited for human subjects.