HCG

Men on AAS who care about preserving testicular function, fertility, and the quality of their eventual natural recovery use HCG. It is standard in evidence-based AAS protocols. It is also standard for TRT users who want to maintain testicular size, intratesticular testosterone (which conventional TRT suppresses entirely), and any residual fertility potential.

On-cycle maintenance: 250–500 IU subcutaneously 2–3 × per week throughout the cycle. This dose keeps testicular function partially active without over-stimulating the testes.

PCT use: 500–1000 IU every other day for 10–14 days before beginning a SERM. This primes Leydig cells for the subsequent natural testosterone recovery phase.

TRT co-administration: 250–500 IU 2–3 × weekly alongside TRT dose. Maintains intratesticular testosterone, testicular volume, and preserves fertility potential for men who want those outcomes.

Reconstitution: Supplied as lyophilized powder with accompanying bacteriostatic water. Swirl gently; do not shake. Store refrigerated after mixing.

Important: Avoid very high continuous doses because over-stimulation can cause Leydig cell desensitization and paradoxically worsen recovery.

Testicular size responses to on-cycle HCG are visible within a few weeks. Recovery of Leydig function during PCT priming is the goal, not immediate testosterone normalization. That comes later through the SERM phase after the HCG bridge.

Use context

HCG is one of the most practically important ancillary compounds in the AAS world, yet it is also one of the most misunderstood. The core function is simple: when exogenous androgens suppress the HPG axis, LH drops, and the testes stop being stimulated. HCG replaces that LH signal.

The nuance is in how and when it is used. On-cycle HCG at low doses (250–500 IU 2–3x weekly) maintains testicular volume, intratesticular testosterone (which matters for fertility and for the smoothness of recovery), and keeps the Leydig cells receptive. This is not the same as PCT and it does not mean SERM use can be skipped at the end of the cycle.

In PCT, HCG is used as a bridge: it primes the Leydig cells before the SERM phase, improving the speed and quality of natural testosterone recovery. The sequence is HCG first, then SERM, not both simultaneously in the early phase.

Using HCG only at the end of a long cycle after extended testicular atrophy rather than maintaining throughout. Running it at very high doses continuously and desensitizing the Leydig cells. Running it during the SERM phase simultaneously rather than sequentially. Not accounting for the estrogen elevation it causes in AAS protocols where AI dose is already calibrated.

Compared with HMG, HCG replaces only LH activity. HMG provides both FSH and LH analog activity, making it superior for fertility restoration when FSH is the limiting factor. Compared with Kisspeptin or Clomiphene PCT, HCG addresses the testicular side of the HPG axis directly rather than working upstream through the pituitary.