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HCG5.5
HCG (Human Chorionic Gonadotropin) Research
Mostly mechanism / observationalLimited safety
7 peer-reviewed studies
What the evidence says
Mostly mechanism / observational
Most HCG (Human Chorionic Gonadotropin) studies are mechanism or observational rather than RCTs that measure a clinical effect — keep findings provisional.
Most evidence is from mixed-quality meta-analyses and randomised trials published 2005–2023 with a typical study size of 51 participants.
Based on 7 studies · 1 meta-analysis · 1 RCT · 1,844 total participants
Confidence
Moderate
By outcome
Fertility & reproduction
Mostly mechanism / observational7 studies
Testosterone & testicular function
Mostly mechanism / observational6 studies
Steady research
1 study in the last 5 years · Latest meta-analysis: 2023
200520142023
1RCTn=29 · very small study2005
These results demonstrate that relatively low dose hCG maintains ITT within the normal range in healthy men with gonadotropin suppression.
29 men with normal reproductive physiology randomized to weekly testosterone enanthate plus saline placebo or 125, 250, or 500 IU hCG every other day for 3 weeks
Testosterone suppressed LH and FSH to 5% and 3% of baseline and collapsed intratesticular testosterone (ITT) by 94% in the placebo arm
ITT rose linearly with hCG dose (P<0.001): 25% below baseline at 125 IU, 7% below at 250 IU, and 26% above baseline at 500 IU
The dual trigger was associated with a significantly higher number of retrieved oocytes, number of mature oocytes, CPR, and LBR in IVF than the hCG trigger.
Hsia LH, Lee TH, Lin YH, Huang YY, Chang HJ, Liu YL. · J Assist Reprod Genet (2023)
Systematic review and meta-analysis of 10 randomized trials (1,638 participants) comparing a GnRH-agonist + hCG dual trigger against the conventional hCG-only trigger in IVF
hCG is the established reference 'trigger' for final oocyte maturation and ovulation — the comparator the entire analysis is built around
The dual trigger improved live-birth and clinical-pregnancy rates and oocyte yield over hCG alone, mainly in fresh embryo-transfer cycles
R-hFSH (combined with hCG) is effective for the restoration of fertility in the majority of men with HH.
Warne DW, Decosterd G, Okada H, Yano Y, Koide N, Howles CM. · Fertil Steril (2009)
Combined analysis of four Phase III open-label studies in 100 men with complete idiopathic or acquired hypogonadotropic hypogonadism, pretreated with hCG for 3-6 months then hCG plus recombinant FSH
After hCG pretreatment, 81 men reached normal serum testosterone but remained azoospermic; of these, 84% achieved spermatogenesis and 69% reached a sperm concentration ≥1.5 million/ml
Large baseline testicular volume, low BMI, and advanced sexual maturity predicted a good response
Previously virilised men with adult-onset HH and normal testicular volume respond well to monotherapy in which human chorionic gonadotrophin (hCG) acts as a long-acting LH-analogue stimulating spermatogenesis.
Prior M, Stewart J, McEleny K, Dwyer AA, Quinton R. · Clin Endocrinol (Oxf) (2018)
Clinical review of sperm-induction protocols in men with hypogonadotropic hypogonadism
Adult-onset HH men with normal testicular volume often respond to hCG monotherapy, whereas congenital HH (e.g. Kallmann syndrome) generally requires combined hCG plus FSH
Key predictors of success: prior testicular development (volume >4 ml), inhibin B >60 pg/ml, and no history of cryptorchidism
Management strategies for anabolic steroid-associated hypogonadism (ASIH) include judicious use of testosterone replacement therapy, hCG, and selective estrogen receptor modulators.
Rahnema CD, Lipshultz LI, Crosnoe LE, Kovac JR, Kim ED. · Fertil Steril (2014)
Review of management for men with hypogonadism after anabolic-androgenic steroid use (the population most overlapping with off-label hCG use)
Positions hCG alongside testosterone and SERMs in restoring the suppressed hypothalamic-pituitary-gonadal axis and fertility
Notably, the authors intended a meta-analysis but found no studies meeting quality inclusion criteria — an honest marker of how thin the controlled evidence is for this use