Evaluating the impact of Metformin doses on Pituitary Hormones (FSH, LH, PRL, and Estrogen) regulation in women with PCOS

Abstract

Objective: This study aimed to investigate how varying doses of metformin influence specific pituitary hormones (FSH, LH, PRL) and ovarian estrogen activity in women affected by polycystic ovary syndrome (PCOS). Estrogen was included because of its feedback regulation on pituitary gonadotropins within the hypothalamic–pituitary–ovarian axis.

Methods: Ninety women aged 16 to 45 years diagnosed with PCOS according to the Rotterdam criteria were randomly assigned to three treatment groups. Each group received a daily dose of metformin—500 mg, 800 mg, or 1000 mg—for a duration of three months. Post-treatment serum concentrations of follicle-stimulating hormone (FSH), luteinizing hormone (LH), prolactin (PRL), and estrogen were measured using enzyme-linked immunosorbent assay (ELISA).

Results: Patients who received a daily dose of 1000 mg of metformin exhibited clear reductions in serum levels of follicle-stimulating hormone (FSH) and luteinizing hormone (LH), indicating a measurable endocrine response to the higher dosage as well as to estrogen when compared with their initial baseline levels. Conversely, prolactin (PRL) levels showed a significant rise following treatment. This pattern of hormonal fluctuation appears to be linked to dosage intensity, suggesting a dose-dependent mechanism of endocrine modulation. These findings imply that progressive titration of metformin may exert regulatory effects on pituitary function in PCOS patients, thereby aiding in the restoration of hormonal equilibrium and enhancing reproductive outcomes.