Background and Objective: Throughout the history, medicinal plants have established their roles as therapeutic and remedial agents. Green tea contains polyphenolic compounds including flavonoids and catechins alleged to exert biological effects. Taking advantage of Green tea effects on male sex hormones, the study was an attempt to assess its effects on female sex hormones and gonadotropins in rats.

Materials and Methods: In this experimental study, 15 female Wistar rats were allocated to 3 groups of 5. Two groups received green tea1.5% and 3.5%, respectively as the only source of drink whilst the control group received only tap water. Blood samples were taken at the end of the 28^th day and serum concentration of LH, FSH, estrogen, and progesterone was measured.

Results: The results illustrated that serum LH and estrogen significantly decreased in groups receiving green tea compared to the control group (p<0.001, p<0.05, respectively). Serum FSH increased to a small extent, though not significantly. In the meantime, serum progesterone showed a significant increase in groups receiving green tea compared to the control group (p<0.001).

Conclusion: Our study asserts that green tea decreases LH and estrogen and increases progesterone without any significant effect on FSH level.