Background and objective: soybean tempeh contains isoflavones that are able to bind to estrogen receptors, so they have estrogenic properties. This study aims to prove that the administration of tempeh soybean extract during periods of perception can inhibit the formation of ovarian follicles. Method: posttest only control group design, using female rats aged 12-13 weeks with BB 150 g, a research site in Udayana University’s integrated laboratory. Result: the results showed that there were significant differences in the mean number of follicles in the three groups, namely primordial, primary, secondary was p <0.01; atreticfollicles wasp <0.05. Conclusion: the administration of ethanol extract of tempeh during the perimenopause period can inhibit the formation of primordial follicles, primary follicles, and secondary follicles. High doses can increase the average number of atretic follicles.
Keywords: ethanol extract tempeh, perimenopause period, ovarian follicles