INS and COVID-19: In this review focused on biguanides, thiazolidinediones, sulfonylureas, dipeptidyl peptidase-4 (DPP4) inhibitors, glucagon-like peptide-1 receptor (GLP-1R) agonists, sodium-glucose cotransporter-2 (SGLT2) inhibitors and insulin, their profiles will be discussed in relation to COVID-19.