A new study published in Experimental and Clinical Endocrinology Diabetes assessed whether sex determines the effect of metformin on lactotroph secretory function. This study enrolled 25 women and 12 men with mildly elevated serum prolactin levels 25 75 8201 ng mL and concomitant type 2 diabetes. All participants were administered metformin 3 8201 g daily. The results showed that at baseline there were no significant differences in circulating levels of glucose and lipids insulin sensitivity hormones Jostel s SPINA GT and SPINA GD indices between women and men. Whereas in both the sexes metformin reduced fasting glucose levels and HOMA1 IR homeostatic Model Assessment Index to identify insulin resistance . However only in women metformin decreased elevated prolactin levels and this effect correlated with an improvement insulin sensitivity as well as with the impact on SPINA GT. Therefore the findings of this study indicated that the effect of metformin on serum prolactin levels is sex dependent.