Metformin is a drug recommended as the first-line agent for the treatment of patients with type 2 diabetes mellitus due to its high efficiency and good safety profile. Additionally, literature has described its favourable effect in treating several other diagnoses. This review aims to summarize recent research on metformin modification and derivatization, which has led to agents with higher efficiency or expanded the application possibilities of metformin. Namely, buformin, phenformin, imeglimin, lixumistat, IM176 derivatives, moroxydine, proguanil, cycloguanil, metformin sulfenamides and sulphonamides, polypeptide derivative LysMET, artesinate-metformin conjugate AM2. Additionally, salts such as metformin hydrochloride, metformin hydrobromide, metformin hydroiodide, metformin acetate, metformin embonate, metformin threonate, metformin tartrate, metformin citrate, metformin mesylate and metformin maleate. The goal is to highlight recent research efforts and introduce perspectives for novel and effective biomedical substances within the still unexplored field.