Objective: To investigate the effects of follitropin alfa and beta on the myoelectrical activity of rat myometrium using signal-processing techniques. Design: Prospective, placebo-controlled study. Setting: Animal and pharmacology laboratory at Inonu University. Animal(S): Forty-five female Wistar albino rats. Intervention(s): Thirty of 45 animals involved in the experiment were registered as the superovulation group. After two successive normal estrous cycles, these animals were put into three equal subgroups. Group 1 was the control; animals were given 0.9% saline. Groups 2 and 3 were treated with follitropin alfa (Gonal-f) and follitropin beta (Puregon), respectively. The other 15 animals were ovariectomized (OVX) and subjected to the same protocol. The uterine myoelectrical signals were recorded and analyzed using a Matlab environment. Main Outcome Measure(s): Power/second, variance, and the effects of recombinant human follicle-stimulating hormone (FSH) on myoelectrical signals were assessed through temporal, spectral, and joint time-frequency analysis. The uterine endometrium and ovarian morphology were also assessed concerning primary follicles, antral follicles, and corpora lutea. Result(S): The power and some characteristic spectral components of myoelectrical signal were reduced with the administration of follitropin alfa and beta. No statistically significant difference was detected between endometrial and ovarian histology of the rats treated with these follitropins. Conclusion(s): Uterine myoelectrical signals change with administration of recombinant human FSH preparations. Follitropin beta and, more precisely, follitropin alfa suppress the spectral components and power of the myoelectrical signals, which provides uterine quiescence.