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Comparison

hCG vs Triptorelin

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

hCG Triptorelin
Class Reproductive & HPTA Reproductive & HPTA
Evidence Regulator approved Regulator approved
Human trials ~60 ~45
Half-life ~24-36 hours ~3 hours (immediate release)
Reported range 250 mcg - 1.5 mg 100 mcg
Frequency 2-3x weekly (dosed in international units) Single dose in restart protocols; depot dosing for approved use
Routes Subcutaneous, Intramuscular Subcutaneous, Intramuscular
FDA approved Yes Yes
Research use only No No
Banned in sport Yes Yes
Studied for Preservation of fertility and testicular volume on TRT, Hypogonadotropic hypogonadism, Ovulation induction Advanced prostate cancer, Endometriosis, Central precocious puberty, HPTA restart research
Reported side effects Gynaecomastia, Water retention, Acne, Mood changes, Injection-site reactions Hot flushes, Initial testosterone flare, Reduced libido, Injection-site reactions, Bone density loss with long use

hCG

Human chorionic gonadotropin is a glycoprotein hormone, not a simple peptide, structurally similar to luteinising hormone and acting at the same LH/CG receptor. In men it stimulates Leydig cells directly to produce testosterone and maintains testicular volume and intratesticular testosterone during exogenous androgen therapy. Because it acts downstream of the pituitary it works even when the HPTA is fully suppressed, which is the practical difference from gonadorelin.

Triptorelin

Triptorelin is a decapeptide GnRH agonist with a D-tryptophan substitution at position 6 that greatly increases receptor affinity and resistance to degradation. A single dose produces a transient flare of LH and FSH; sustained administration downregulates pituitary GnRH receptors and suppresses gonadotropins almost completely. Both behaviours are exploited clinically, for post-cycle restart protocols on one hand and for androgen deprivation in prostate cancer on the other.

hCG vs Triptorelin: common questions

What is the difference between hCG and Triptorelin?

Both are reproductive & HPTA. hCG: A placental glycoprotein hormone that mimics LH directly at the testis, the long-standing standard for preserving fertility on TRT. Triptorelin: A long-acting GnRH agonist that produces an initial LH surge and then profound suppression, depending entirely on how it is dosed.

Which has stronger evidence, hCG or Triptorelin?

They sit at the same evidence level: regulator approved. hCG has about 60 human studies and Triptorelin about 45.

Are hCG and Triptorelin FDA approved?

Both are FDA approved. hCG: Prepubertal cryptorchidism; Hypogonadotropic hypogonadism in males; Ovulation induction. Triptorelin: Palliative treatment of advanced prostate cancer (Trelstar); Central precocious puberty in children aged 2 and older (Triptodur, extended-release, approved 2017).

References

Regulatory and primary sources

  1. PubChem compound record (CID 4369448) ↗ · structure, identifiers, synonyms
  2. DailyMed: FDA-approved labeling for hCG ↗ · indications, dosing, warnings as approved
  3. FDA Drugs@FDA database ↗ · approval history
  4. WADA Prohibited List ↗ · current year
  5. CAS Registry Number 9002-61-3 ↗ · chemical identity
  6. PubChem compound record (CID 25074470) ↗ · structure, identifiers, synonyms
  7. DailyMed: FDA-approved labeling for Triptorelin ↗ · indications, dosing, warnings as approved
  8. FDA Drugs@FDA database ↗ · approval history
  9. CAS Registry Number 57773-63-4 ↗ · chemical identity

Published literature

  1. Khadilkar V, Mondkar SA. Micropenis.Indian J Pediatr 2023.PubMed 37079255 · doi:10.1007/s12098-023-04540-w
  2. Singla N, Bagrodia A, Baraban E, et al.. Testicular Germ Cell Tumors: A Review.JAMA 2025.PubMed 39899286 · doi:10.1001/jama.2024.27122
  3. Rahnema CD, Lipshultz LI, Crosnoe LE, et al.. Anabolic steroid-induced hypogonadism: diagnosis and treatment.Fertil Steril 2014.PubMed 24636400 · doi:10.1016/j.fertnstert.2014.02.002
  4. Abacı A, Besci Ö. A Current Perspective on Delayed Puberty and Its Management.J Clin Res Pediatr Endocrinol 2024.PubMed 38683021 · doi:10.4274/jcrpe.galenos.2024.2024-2-7
  5. Latronico AC, Arnhold IJ. Gonadotropin resistance.Endocr Dev 2013.PubMed 23392092 · doi:10.1159/000342496
  6. Mihm M, Gangooly S, Muttukrishna S. The normal menstrual cycle in women.Anim Reprod Sci 2011.PubMed 20869180 · doi:10.1016/j.anireprosci.2010.08.030
  7. Talwar GP, Raghupathy R. Anti-fertility vaccines.Vaccine 1989.PubMed 2665354 · doi:10.1016/0264-410x(89)90043-1
  8. Naelitz BD, Momtazi-Mar L, Vallabhaneni S, et al.. Testosterone replacement therapy and spermatogenesis in reproductive age men.Nat Rev Urol 2025.PubMed 40346275 · doi:10.1038/s41585-025-01032-8
  9. Keating GM. Triptorelin embonate (6-month formulation).Drugs 2010.PubMed 20166771 · doi:10.2165/11202230-000000000-00000
  10. Sharma S, RoyChoudhury S, Chakraborty P, et al.. Comparative analysis of low-dose letrozole versus GnRH agonist on implantation markers and IVF outcomes in symptomatic adenomyosis: a randomized trial.Sci Rep 2025.PubMed 41476263 · doi:10.1038/s41598-025-32974-z
  11. Leone Roberti Maggiore U, Scala C, Remorgida V, et al.. Triptorelin for the treatment of endometriosis.Expert Opin Pharmacother 2014.PubMed 24832495 · doi:10.1517/14656566.2014.916279
  12. Brown J, Farquhar C. An overview of treatments for endometriosis.JAMA 2015.PubMed 25603001 · doi:10.1001/jama.2014.17119
  13. Beebeejaun Y, Copeland T, Duffy JMN, et al.. Triggering oocyte maturation in in vitro fertilization treatment in healthy responders: a systematic review and network meta-analysis.Fertil Steril 2025.PubMed 39547644 · doi:10.1016/j.fertnstert.2024.11.011
  14. Li J, Lin Z, Mo S, et al.. Pretreatment with or without GnRH-agonist before frozen-thawed embryo transfer in patients with PCOS: a systematic review and meta-analysis.J Ovarian Res 2024.PubMed 38907340 · doi:10.1186/s13048-024-01410-7
  15. Lahlou N. [Pharmacodynamics of triptorelin].Rev Prat 2005.PubMed 15822863
  16. Hu KL, Wang S, Ye X, et al.. GnRH agonist and hCG (dual trigger) versus hCG trigger for follicular maturation: a systematic review and meta-analysis of randomized trials.Reprod Biol Endocrinol 2021.PubMed 34059045 · doi:10.1186/s12958-021-00766-5

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.