INS and polycystic ovary syndrome: Also, other drugs such as clomifene citrate and thiazolidinediones (e.g., rosiglitazone and pioglitazone) are often used to increase insulin sensitivity and decrease insulin resistance; these drugs are considered to be first-line ovulation-inducing drugs in infertile women with PCOS either alone or in combination with metformin (El-Khayat et al., 2016).