Adding HCG
to a TRT Protocol

The Mechanism

Why Add HCG to TRT

Human chorionic gonadotropin (HCG) is a hormone that mimics luteinizing hormone (LH) at the Leydig cell receptor in the testes. On TRT without HCG, the hypothalamic-pituitary axis detects exogenous testosterone and suppresses LH production — which signals the testes to stop their own testosterone production. Over time, the testes atrophy and intratesticular testosterone (ITT) drops significantly, affecting sperm production and testicular volume.

HCG bypasses the suppressed LH signal by acting directly on the Leydig cells. It maintains intratesticular testosterone production, preserves testicular volume, and maintains some degree of fertility even on a suppressive TRT protocol. For men who may want to father children in the future, or for those who notice testicular atrophy and associated discomfort, HCG is the standard adjunct.

The Protocol

Standard HCG Dosing and Administration

The most common HCG protocol on TRT is 250 IU subcutaneously every other day (EOD). This maintains stable HCG levels given its ~36-hour half-life, avoids the estradiol-driving peaks that higher doses can produce, and is well-tolerated by most men. Some protocols use 500 IU twice weekly, timed with testosterone injections — this is simpler but produces more variation in HCG levels between doses.

HCG is available as a lyophilized powder that requires reconstitution with bacteriostatic water, similar to research peptides. Standard reconstitution: add 1mL BAC water to a 5,000 IU vial for 5,000 IU/mL concentration. For 250 IU per dose, draw 5 units on a U-100 syringe. Store refrigerated and use within 30 days. Reconstitution is straightforward and the Protocol app logs HCG doses alongside testosterone the same way it handles any multi-compound protocol.

Note that HCG can raise Estradiol — it stimulates aromatase in the testes in addition to testosterone production. If you're already managing E2 on TRT, adding HCG may require Estradiol monitoring and possible AI adjustment. Work with your prescribing physician on any protocol changes.

FAQ

HCG on TRT Questions