RecruitingPhase 2Drug trialEvaluation of the Chemo-preventive Effect of Combined Topical and Systemic Metformin on Oral LeukoplakiaThere is no consensus on treatment of leukoplakia but surgical excision is the preferred choice if suitable in size, which does not prevent clinical recurrence and malignant transformation. Chemoprevention is a new direction in the management of OL using various topical and systemic agents such as; vitamin A, lycopene, celecoxib, green tea extract, and metformin. While metformin cannot realistically be used as cancer mono-therapy, it can be used as an adjunct and can have a more promising effect on lesions that have yet to undergo malignant transformation. Thus, the aim of this study is to investigate the efficacy of combined chemo-preventive effect of topical and systemic Metformin on oral leukoplakia.