hCG vs LH

Glycoprotein hormone binding LH receptor on Leydig cells; stimulates testosterone production; prevents testicular atrophy during TRT; maintains spermatogenesis via FSH-like activity

Human chorionic gonadotropin (hCG) is a glycoprotein hormone that acts as a functional analogue of luteinizing hormone (LH), binding to LH receptors on Leydig cells in the testes and granulosa cells in the ovaries to stimulate steroidogenesis. In men, hCG stimulates testicular testosterone production directly, making it a widely used clinical tool for hypogonadotropic hypogonadism, male fertility support, and preservation of testicular function alongside testosterone replacement therapy. Clinical research demonstrates hCG effectiveness for improving testosterone levels and sperm parameters in males with gonadotropin deficiency, as well as for triggering final oocyte maturation in IVF protocols. hCG is an FDA-regulated biologic available in multiple approved formulations; use requires physician supervision due to dose-dependent effects on testosterone, estradiol, and reproductive signaling. hCG dosage in TRT support: in men using testosterone replacement therapy, hCG is prescribed to prevent testicular atrophy and maintain intratesticular testosterone levels needed for spermatogenesis. Typical clinical doses range from 250 to 500 IU subcutaneously administered 2–3 times per week, though protocols vary by provider and individual response. At higher doses, hCG's stimulation of testicular testosterone can also increase aromatization to estradiol — a clinically relevant consideration in TRT management requiring estrogen monitoring. hCG vs gonadorelin: both are used in men's health for testicular preservation alongside TRT, but they act at different axis levels. hCG acts directly on Leydig cell LH receptors, bypassing the pituitary entirely — a direct trophic signal to the testes. Gonadorelin acts upstream at the pituitary to stimulate endogenous LH and FSH release, preserving the full hypothalamic-pituitary-gonadal axis including FSH-driven spermatogenesis. For men prioritizing sperm production, gonadorelin's preservation of FSH signaling offers a potential advantage; for men primarily focused on testicular volume and intratesticular testosterone maintenance, hCG provides a well-validated, direct approach. Telehealth and men's health providers offering hCG and gonadorelin protocols are listed in the PeptideBase directory.

Binds LH receptors on testicular Leydig cells, stimulating the cholesterol → testosterone biosynthetic pathway. In women, the LH surge triggers ovulation and supports luteal phase progesterone production.

LH (luteinizing hormone) is an endogenous heterodimeric glycoprotein hormone produced by pituitary gonadotrophs, sharing the common alpha subunit with FSH, TSH, and hCG, with a unique LH-beta subunit structurally homologous to hCG-beta; LH drives sex steroid synthesis through pulsatile release regulated by hypothalamic GnRH, and mediates the midcycle LH surge that triggers ovulation in women and sustains Leydig cell testosterone production in men. LH activates its receptor (LHR/LHCGR) on ovarian theca cells to stimulate androgen synthesis (which granulosa cells aromatize to estrogen under FSH regulation) and triggers follicular rupture and corpus luteum formation during the ovulatory surge; in men, tonic LH stimulates Leydig cell testosterone biosynthesis through cAMP/StAR pathway activation. A double-blind randomized controlled trial of supplemental recombinant LH (lutropin alfa) during controlled ovarian stimulation for ART demonstrated comparable clinical outcomes to FSH-only protocols in patients with baseline LH deficiency, providing evidence that lutropin alfa can serve as an effective LH substitute in gonadotropin-deficient women undergoing fertility treatment. Lutropin alfa (Luveris; Pergoveris in co-formulation with FSH) is approved in the European Union and several other jurisdictions for stimulation of follicular development in women with profound LH deficiency, but is not broadly approved in the United States; endogenous LH is not used as a therapeutic agent, and hCG — structurally similar to LH with a longer plasma half-life — is typically used as an LH surrogate for ovulation triggering and luteal phase support in US clinical practice.