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FDA Approved Sexual & Reproductive Health

Elagolix

also known as: Orilissa, NBI-56418

The first oral GnRH antagonist — a non-peptide small molecule that suppresses estrogen production without injection, FDA-approved for endometriosis pain.

A non-peptide, orally bioavailable GnRH receptor antagonist that produces dose-dependent suppression of estradiol, offering medical management of endometriosis without the injection burden of peptide GnRH agonists.

Mechanism of action

Competitive antagonist at the GnRH receptor (GnRHR) on anterior pituitary gonadotrophs. Blocks endogenous GnRH binding, reducing LH and FSH secretion and consequently suppressing ovarian estradiol production. Unlike GnRH agonists (leuprolide), does not cause initial hormonal flare. Dose-dependent: 150 mg QD produces partial suppression; 200 mg BID produces near-complete suppression.

Primary uses

  • Endometriosis-associated pain
  • Heavy menstrual bleeding due to uterine fibroids (in combination, as Oriahnn)

Typical dosing

150–200 mg once or twice daily (oral)

150 mg QD for dysmenorrhea-predominant pain; 200 mg BID for deeper/more severe disease. Bone density monitoring recommended.

Regulatory status

FDA-approved in 2018 (Orilissa, AbbVie) for moderate-to-severe endometriosis-associated pain. Available at 150 mg once daily (24 months max) and 200 mg twice daily (6 months max).

References

  1. [clinical-trial] Taylor HS, et al. "Treatment of endometriosis-associated pain with elagolix, an oral GnRH antagonist (Elaris EM-I and EM-II)." N Engl J Med, 2017;377:28-40.
  2. [fda-pi] Orilissa (elagolix) Prescribing Information. AbbVie.

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.

Relugolix

The oral alternative to Lupron — a once-daily pill that suppresses testosterone to castrate levels for prostate cancer without the flare, injection, or cold-chain requirements of injectable GnRH agonists.

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.

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.