Ala’a Ahmed Alghamdi , Sara Mohssin Fageeh , Noura Hamdan Alotaibi,Saad Aied Saeed Abohasel, Shatha khaled M Gadah, Abdullah Saud Abdullah Alshebli, Ghaliah Amin Thiga
Background: Metformin is considered as the main antidiabetic medicine which has been appeared to improve anticipation of T2DM patients as an essential end-point for prevention of diabetes. Objective: This study aimed at providing an update on the effect of metformin in prevention of T2DM. Methods: The online medical database was searched then the English articles from 2009 – 2020 were included in the review. Results: There were 36 studies involved concentrating on the prevention effect of metformin on type 2 diabetes mellitus. Conclusion: many studies propose that metformin is an active, tolerable, cheap, and cost-saving interference that can inhibit or prevent development of diabetes. Most of the metformin studies showed that metformin is not used in real-world settings. Thus, metformin needs more evidence-based treatment studies among high risk patients to evaluate its advantage in prevention or delay of diabetes and assessing its side effects and long-term effects. Keywords: metformin, type 2 diabetes mellitus (T2DM), prevention, delay, prediabetes.