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Comparison

Gonadorelin vs HMG

Both are reproductive & HPTA, so the meaningful differences are in kinetics, evidence and regulatory status.

Gonadorelin HMG
Class Reproductive & HPTA Reproductive & HPTA
Evidence Regulator approved Regulator approved
Human trials ~30 ~50
Half-life ~2-10 minutes ~30-60 hours
Reported range 100-200 mcg 75-150 mcg
Frequency 2-3x weekly, or more frequently in fertility protocols 2-3x weekly (dosed in international units)
Routes Subcutaneous, Intramuscular Subcutaneous, Intramuscular
FDA approved Yes Yes
Research use only No No
Banned in sport Yes Yes
Studied for Preservation of testicular function during TRT, Hypogonadotropic hypogonadism, Fertility Assisted reproduction (IVF), Male fertility restoration (off-label in the US)
Reported side effects Injection-site reactions, Headache, Flushing, Nausea Injection-site reactions, Headache, Abdominal discomfort, Gynaecomastia in men

Gonadorelin

Gonadorelin is identical to endogenous gonadotropin-releasing hormone, a decapeptide secreted in pulses by the hypothalamus. Pulsatile delivery stimulates pituitary release of LH and FSH, maintaining testicular steroidogenesis and spermatogenesis. The pharmacology is strictly pulse-dependent: continuous exposure downregulates the receptor and suppresses gonadotropins instead, which is how GnRH agonists are used for chemical castration. Its very short half-life is the reason frequent dosing is required.

HMG

Human menopausal gonadotropin is a purified glycoprotein preparation from the urine of postmenopausal women, containing roughly equal FSH and LH activity. In male fertility protocols the FSH component is the point: hCG alone restores intratesticular testosterone but does not supply the FSH signal to Sertoli cells that spermatogenesis also requires. It is therefore added when hCG monotherapy fails to restore sperm counts.

Gonadorelin vs HMG: common questions

What is the difference between Gonadorelin and HMG?

Both are reproductive & HPTA. Gonadorelin: Synthetic gonadotropin-releasing hormone, increasingly used alongside TRT to maintain testicular function. HMG: A urine-derived preparation containing both FSH and LH activity, used where spermatogenesis needs FSH support.

Which has stronger evidence, Gonadorelin or HMG?

They sit at the same evidence level: regulator approved. Gonadorelin has about 30 human studies and HMG about 50.

Are Gonadorelin and HMG FDA approved?

Both are FDA approved. Gonadorelin: Evaluation of hypothalamic-pituitary-gonadal function (US marketing discontinued). HMG: Development of multiple follicles and pregnancy in ovulatory women as part of an assisted reproductive technology (ART) cycle such as IVF (Menopur).

References

Regulatory and primary sources

  1. PubChem compound record (CID 638793) ↗ · structure, identifiers, synonyms
  2. DailyMed: FDA-approved labeling for Gonadorelin ↗ · indications, dosing, warnings as approved
  3. FDA Drugs@FDA database ↗ · approval history
  4. WADA Prohibited List ↗ · current year
  5. CAS Registry Number 33515-09-2 ↗ · chemical identity
  6. PubChem compound record (CID 1662) ↗ · structure, identifiers, synonyms
  7. DailyMed: FDA-approved labeling for HMG ↗ · indications, dosing, warnings as approved
  8. FDA Drugs@FDA database ↗ · approval history

Published literature

  1. van Leusden HA. The flush revisited.Eur J Obstet Gynecol Reprod Biol 1994.PubMed 7713285 · doi:10.1016/0028-2243(94)90289-5
  2. Kyriazis I, Bellos T, Katsimperis S, et al.. Relugolix in treatment of prostate cancer: a review.Arch Ital Urol Androl 2025.PubMed 41247145 · doi:10.4081/aiua.2025.14277
  3. Florio S, Pagnini U, Crispino A, et al.. GnRH and steroids in cancer.Front Biosci 2002.PubMed 12045004 · doi:10.2741/A864
  4. Schwanzel-Fukuda M, Zheng LM, Bergen H, et al.. LHRH neurons: functions and development.Prog Brain Res 1992.PubMed 1480748 · doi:10.1016/s0079-6123(08)64572-0
  5. Armer RE, Smelt KH. Non-peptidic GnRH receptor antagonists.Curr Med Chem 2004.PubMed 15544487 · doi:10.2174/0929867043363983
  6. Dellis A, Papatsoris A. Therapeutic outcomes of the LHRH antagonists.Expert Rev Pharmacoecon Outcomes Res 2017.PubMed 28870102 · doi:10.1080/14737167.2017.1375855
  7. Pace JN, Miller JL, Rose LI. GnRH agonists: gonadorelin, leuprolide and nafarelin.Am Fam Physician 1991.PubMed 1835275
  8. Barbieri RL. Endometriosis 1990. Current treatment approaches.Drugs 1990.PubMed 2190793 · doi:10.2165/00003495-199039040-00003
  9. Lathi RB, Milki AA. Recombinant gonadotropins.Curr Womens Health Rep 2001.PubMed 12112963
  10. Melo P, Eapen A, Chung Y, et al.. Controlled ovarian stimulation protocols for assisted reproduction: a network meta-analysis.Cochrane Database Syst Rev 2025.PubMed 40590303 · doi:10.1002/14651858.CD012586.pub2
  11. Weiss NS, Kostova EB, Mol BWJ, et al.. Gonadotropins for ovulation induction in women with polycystic ovary syndrome.Cochrane Database Syst Rev 2025.PubMed 40193219 · doi:10.1002/14651858.CD010290.pub4
  12. Witz CA, Daftary GS, Doody KJ, et al.. Randomized, assessor-blinded trial comparing highly purified human menotropin and recombinant follicle-stimulating hormone in high responders undergoing intracytoplasmic sperm injection.Fertil Steril 2020.PubMed 32416978 · doi:10.1016/j.fertnstert.2020.03.029
  13. Deeks ED. Highly Purified Human Menopausal Gonadotropin (Menopur(®)): A Profile of Its Use in Infertility.Clin Drug Investig 2018.PubMed 30264288 · doi:10.1007/s40261-018-0703-8
  14. Matsumoto AM. Hormonal therapy of male hypogonadism.Endocrinol Metab Clin North Am 1994.PubMed 7705324
  15. Li J, Peng Y, Dai X, et al.. Human menopausal gonadotropin (HMG) combined different doses of letrozole for treating anovulatory infertility in patients with polycystic ovary syndrome: a randomized controlled trial.J Assist Reprod Genet 2025.PubMed 40193016 · doi:10.1007/s10815-025-03455-z
  16. Wang Y, Li L, Deng K, et al.. Comparison of the combination of recombinant follicle-stimulating hormone and recombinant luteinizing hormone protocol versus human menopausal gonadotropin protocol in controlled ovarian stimulation: A systematic review and meta-analysis.J Evid Based Med 2020.PubMed 32627395 · doi:10.1111/jebm.12390

Literature retrieved from PubMed on October 16, 2026, favouring human studies and reviews. Numbered markers in the text show which paper supports which statement; uncited entries are background reading.

Read this first This page compares published reference data. It is not medical advice and not a recommendation to use either compound. Several compounds documented on this site are not approved for human use.