Estradiol is a powerful inhibitor of FSH (follicle stimulating hormone). What is another factor that is a powerful inhibitor of FSH in the female?

Inhibin, as its name implies, is an inhibitor. The specific action of inhibin is to inhibit the release of FSH. Inhibin occurs as a heterodimer It is produced in the male and the female. Inhibin is produced by the ovarian granulosa cells to prevent more than one follicle (in general) from becoming a mature follicle. The inhibin produced by the Seoli cells of the testes acts to decrease FSH to help in regulation of spermatogenesis. Ref: Molina P.E. (2013). Chapter 8. Male Reproductive System. In P.E. Molina (Ed),Endocrine Physiology, 4e.