Evidence Grade A — Regulatory approved. 194 published studies. 39 registered clinical trials.
Medically reviewed by a licensed medical professional
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Elagolix (sold as Orilissa for endometriosis and as part of Oriahnn for uterine fibroids) is a daily oral tablet that reduces the body's production of oestrogen. It is not a peptide — it is a small molecule drug — but it is included in this database because it targets the same hormonal pathway as peptide-based GnRH treatments. It was the first oral GnRH antagonist approved in the US.
Elagolix is also known by these brand and alternate names:
194 published studies: 132 human, 1 animal, 17 in-vitro, 64 reviews
Elagolix is marketed as Orilissa for endometriosis pain (approved July 2018) and as a component of Oriahnn for heavy menstrual bleeding from uterine fibroids (approved May 2020). Oriahnn combines elagolix with low-dose hormone add-back therapy to mitigate bone density loss.
Clinical trials showed that the higher dose reduced menstrual pain in approximately 76% of patients and non-menstrual pelvic pain in about 55% at six months. The main limitation is bone density loss with prolonged use, which the add-back therapy in Oriahnn helps address. As an oral tablet taken daily, it offers a fundamentally different experience from injectable or implanted hormone treatments, though it requires consistent daily dosing. It is important to note that elagolix is not a peptide — it is included in this database because it targets the same GnRH pathway as peptide-based treatments.
Elagolix blocks the GnRH receptor in the pituitary gland, reducing the signals that drive oestrogen and progesterone production. What sets it apart is dose flexibility: at a lower dose (150 mg once daily), it partially suppresses oestrogen, managing pain while preserving enough hormone to protect bone density. At a higher dose (200 mg twice daily), suppression is more complete. This tuneable approach distinguishes it from injectable GnRH treatments, which generally produce near-complete hormone suppression regardless of dose.
Clinical trials showed that the higher dose of elagolix reduced menstrual pain in about 76% of endometriosis patients and non-menstrual pelvic pain in approximately 55% at six months. The key advantage over injectable hormone treatments is the oral tablet format with dose flexibility — lower doses partially suppress oestrogen (managing pain while preserving bone density), while higher doses provide more complete suppression. The main limitation is bone density loss with prolonged use, which restricts treatment duration to 6-24 months depending on the dose. The Oriahnn product for fibroids addresses this by including low-dose hormone add-back therapy. Commercially, elagolix has been overshadowed by relugolix combination therapy (Myfembree), which offers once-daily dosing with built-in hormonal add-back in a single tablet.
PeptideTrace tracks 39 registered clinical trials for Elagolix sourced from ClinicalTrials.gov.
Comparison of Elagolix and OCPs in Reducing Endometriosis Associated Pelvic Pain
Role of Menopause in Thermoregulation
Brain Blood Flow Responses to Stress: Sex Differences
Pre-IVF Treatment With a GnRH Antagonist in Women With endometriosis_temp
A Study to Evaluate Changes in Hair in Adult Participants Taking Oral Oriahnn Capsules With Heavy Menstrual Bleeding (HMB) Associated With Uterine Fibroids (UF)
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Health Canada Market Authorisation
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Elagolix is an oral, non-peptide small molecule GnRH receptor antagonist (molecular weight 631.6 Da). It is NOT a peptide. It was the first oral GnRH antagonist approved in the US and enables dose-dependent, partial-to-full estrogen suppression.
Elagolix competitively antagonizes the GnRH receptor in the anterior pituitary, suppressing LH and FSH release in a dose-dependent manner. At the lower dose (150 mg QD), it produces partial estrogen suppression (mean ~40 pg/mL), preserving some estrogenic activity. At the higher dose (200 mg BID), it produces near-complete suppression (~12 pg/mL). This dose-dependent titration distinguishes it from injectable GnRH agonists, which produce full suppression.
Elagolix is marketed as Orilissa (endometriosis-associated pain, approved July 23, 2018) and as a component of Oriahnn (elagolix + estradiol + norethindrone acetate for uterine fibroids with heavy menstrual bleeding, approved May 29, 2020). In Elaris EM-I/EM-II (N=871/817), the 200 mg BID dose achieved dysmenorrhea response in 75.8% versus 19.6% with placebo. Non-menstrual pelvic pain response: 58.5% versus 36.5%. AbbVie markets both products.
Carbetocin has not been approved by the FDA. It is registered in over 80 countries for prevention of uterine atony and excessive bleeding after caesarean delivery. A heat-stable formulation was added to the WHO Essential Medicines List in 2019. The CHAMPION trial (WHO, 2018; over 29,000 women) compared a heat-stable carbetocin formulation to oxytocin for preventing postpartum haemorrhage after vaginal delivery, and found it to be non-inferior. The heat-stable formulation addresses a significant limitation of oxytocin, which degrades in warm climates without refrigeration — a major concern in low-resource settings where postpartum haemorrhage causes the most deaths. Its regulatory status varies by jurisdiction.
Nafarelin is marketed as Synarel (approved 1990) for endometriosis and central precocious puberty. It requires administration as one spray in each nostril twice daily — a higher frequency than injectable alternatives but avoids needles entirely, which can be a significant advantage for some patients, particularly children. Clinical trials showed symptom improvement in 75–92% of endometriosis patients. However, absorption can be affected by nasal congestion or concurrent use of nasal decongestants, which can be a practical limitation. As with all GnRH agonists, prolonged use leads to bone density loss, and treatment for endometriosis is typically limited to six months. Nafarelin occupies a niche for patients who prefer non-injectable hormone suppression, though it has become less commonly prescribed as longer-acting depot injections and oral alternatives have become available.
Triptorelin is marketed as Trelstar (approved 2000) for advanced prostate cancer, available as intramuscular depot injections in monthly (3.75 mg), three-monthly (11.25 mg), and six-monthly (22.5 mg) formulations. It is also widely used internationally for gender-affirming care and central precocious puberty. Triptorelin is one of the most commonly used GnRH agonists globally, though it faces the same competitive pressure as other agents in this class from newer oral GnRH antagonists like relugolix, which avoid the initial hormone flare and offer potential cardiovascular advantages. Clinical data demonstrate reliable testosterone suppression comparable to other GnRH agonists in this class.
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This content is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional before making decisions about your health.
