Bypassing a shut pituitary

When the pituitary is quiet, from outside testosterone, a pituitary problem, or a weak signal from the brain, the testes lose both FSH and LH and shrink. HMG goes straight to the gonads, so it works no matter where the upstream signal broke. Paired with hCG, it restarts sperm in most men with low pituitary output. It is the downstream half of the system, supplied directly.