A newer approach receiving recent attention is Triptorelin, the GnRH agonist. This is used in a continuous manner to chemically castrate a man, but in a one off dose, has been reported to kick start the PTA in a hypogonadic BB. Triptorelin is a synthetic analogue of GnRH. It causes constant stimulation of the pituitary gland and by acting as such, it stimulates the pituitary gland to pump out LH and FSH. The dose needed to cause chemical castration is much greater than the dose one would use to restart HPTA. The way triptorelin hinders gonadotropin release is similar to how HCG wil hinder test production in the testes. A small amount of HCG will stimulate the Leydig cells to produce testosterone, but too much will desensitize the Leydig cells. This is what GnRH does, but with the pituitary gland. Triptorelin has been studied to restore full HPTA function in a steroid user who cycled for 13 years. Due to it's nature it is advised that triptorelin only be used if coming off long-term blasting and cruising or if one plans to cease AAS forever.
Its action in the male body is like that of LH, stimulating the Leydig cells in the testes to produce testosterone even in the absence of endogenous LH. HCG is therefore used during longer or heavier steroid cycles to maintain testicular size and condition, or to bring atrophied (shrunken) testicles back up to their original condition in preparation for post-cycle Clomid therapy. This process is necessary because atrophied testicles produce reduced levels of natural testosterone, this situation should be rectified prior to post-cycle Clomid therapy.