FDA Approved Sexual & Reproductive Health

Triptorelin

also known as: Trelstar, Triptodur, Decapeptyl, Gonapeptyl

A widely used long-acting GnRH agonist — FDA-approved as Trelstar for advanced prostate cancer and as Triptodur for pediatric central precocious puberty; approved internationally (Decapeptyl, Gonapeptyl) for endometriosis, uterine fibroids, and female infertility protocols.

A synthetic GnRH agonist differing from endogenous GnRH by a D-Trp substitution at position 6, which resists enzymatic degradation and extends receptor binding. Produces an initial gonadotropin surge followed by sustained GnRHR desensitization and chemical castration. Marketed in the US as Trelstar (1/3/6-month IM depots for prostate cancer) and Triptodur (6-month IM depot for pediatric CPP); extensively used internationally as Decapeptyl/Gonapeptyl for gynecologic indications and IVF downregulation.

Mechanism of action

Binds GnRHR on pituitary gonadotrophs; continuous exposure causes receptor desensitization and downregulation after an initial testosterone/estradiol flare. Results in medically reversible chemical castration.

Primary uses

  • Advanced prostate cancer (Trelstar — palliative androgen deprivation)
  • Central precocious puberty, pediatric (Triptodur)
  • Endometriosis (ex-US)
  • Uterine leiomyomata (ex-US)
  • IVF downregulation in long-protocol controlled ovarian stimulation (ex-US)
  • Female breast cancer, premenopausal ovarian suppression (ex-US adjuvant endocrine therapy)

Typical dosing

3.75–22.5 mg monthly to every 6 months (intramuscular depot)

Trelstar prostate cancer: 3.75 mg IM monthly, 11.25 mg every 3 months, or 22.5 mg every 6 months. Triptodur CPP: 22.5 mg IM every 24 weeks.

Regulatory status

FDA-approved as Trelstar (triptorelin pamoate, Verity Pharmaceuticals / Allergan, first approved 2000) in 1-, 3-, and 6-month IM depot formulations for palliative treatment of advanced prostate cancer; and as Triptodur (Arbor Pharmaceuticals / Azurity, approved 2017) as a 22.5 mg 6-month IM depot for central precocious puberty in children aged 2 years and older. Approved internationally as Decapeptyl and Gonapeptyl across additional indications.

References

  1. [fda-pi] Trelstar (triptorelin pamoate for injectable suspension) Prescribing Information. Verity Pharmaceuticals.
  2. [fda-pi] Triptodur (triptorelin) Prescribing Information. Azurity Pharmaceuticals.
  3. [review] Klotz L, et al. "The efficacy and safety of degarelix: a 12-month, comparative, randomized, open-label, parallel-group phase III study in patients with prostate cancer." BJU Int, 2008;102:1531-1538 (comparative GnRH-agonist vs antagonist context).

Related peptides

Leuprolide

The prototypical long-acting GnRH agonist, FDA-approved across multiple formulations (Lupron Depot, Eligard, Fensolvi, Camcevi) for advanced prostate cancer, endometriosis, central precocious puberty, uterine fibroids, and IVF protocols.

Goserelin

AstraZeneca's Zoladex — a long-acting GnRH agonist delivered as a subcutaneous biodegradable implant. FDA-approved for advanced prostate cancer, advanced breast cancer in premenopausal women, endometriosis, and endometrial thinning prior to ablation.

Histrelin

Endo Pharmaceuticals' Supprelin LA (pediatric) and Vantas (adult prostate cancer) — a 12-month subcutaneous hydrogel implant delivering histrelin for continuous GnRH-receptor suppression over a full year, minimizing dosing burden for pediatric CPP patients and adult prostate cancer patients alike.

Degarelix

Ferring's Firmagon — a GnRH antagonist for advanced prostate cancer that achieves castrate testosterone within 3 days, eliminating the clinical flare risk of GnRH-agonist therapy in patients with symptomatic bone metastases or impending spinal cord compression.

Gonadorelin

The native GnRH decapeptide — the hypothalamic signal that drives LH/FSH release and downstream testosterone/estradiol production. Historically FDA-approved (Factrel, Lutrepulse), now widely used in TRT-adjacent fertility protocols as a testicular-preservation alternative to HCG.
Disclaimer

This entry is for educational purposes only and does not constitute medical advice. Dosing information reflects published regulatory or research data and is not a recommendation. Many compounds described here are not approved for human use in the United States. Consult a licensed medical professional before considering any peptide therapy.