Copyright © 2015 The Author(s). Diabetes mellitus is expensive; one of the top 10 most costly health concerns for employers. Individuals with type 2 diabetes mellitus (T2DM) who achieve glycemic targets through healthy lifestyles and appropriate glucose-lowering agents lessen diabetes-related complications. The purpose of this article is to provide a brief review of a first-line agent used in treating T2DM, the biguanide metformin hydrochloride. Implications for health providers who assist employees who use metformin also are addressed.