Metformin is a drug classically used as a first-line treatment for type 2 diabetes. In recent years, interest has grown around its use as a therapeutic tool for other conditions such as metabolic syndrome and polycystic ovary syndrome (R). It has also been found to improve various diseases of the skin (R, R).
Metformin has been shown to permeate rat skin in vitro within 24 hours after application, when delivered as a solution, encapsulated in nanoparticles or loaded onto ethosomes (R, R). Solid lipid nanoparticles of metformin also appear to increase its penetration into the epidermis of mice skin (R).