Why We Can’t Have the Male Contraceptive Pill(bloomberg.com)

  1. The hypothalamus produces GnRH.
  2. In response to stimulation by GnRH, the pituitary produces LH and
     FSH.
  3. In response to FSH and LH, the testes produce sperm and
     testosterone, respectively.
  4. Testosterone inhibits the production of GnRH by the hypothalamus (a
     negative feedback mechanism). This effectively keeps testosterone
     levels regulated.

  1. The increased testosterone inhibits the production of GnRH by the
     hypothalamus.
  2. In absence of GnRH, the pituitary produces less FSH and LH.
  3. In absence of FSH, the testes produce less sperm (this is the
     contraceptive effect). In absence of LH, the testes produce less
     testosterone.