[1][7] Side effects of relugolix include menstrual abnormalities, hot flashes, excessive sweating, headache, and decreased bone mineral density.

[1] Unlike most other GnRH modulators, but similarly to elagolix (brand name Orilissa), relugolix is a non-peptide, small-molecule compound and is orally active.

[1] Relugolix is a selective antagonist of the gonadotropin-releasing hormone receptor (GnRHR), with a half-maximal inhibitory concentration (IC50) of 0.12 nM.

[11] Lower doses of relugolix (<40 mg/day) are under investigation for achieving partial sex hormone suppression in the treatment of endometriosis and uterine fibroids.

[14] This is intended to reduce the incidence and severity of menopausal symptoms such as hot flushes and decreased bone mineral density that are secondary to estrogen deficiency.

[12][13] It was the second orally active GnRH antagonist to be introduced for medical use, following elagolix (brand name Orilissa) in July 2018.

[12][5] The FDA approved relugolix based on evidence from a clinical trial (NCT03085095) of 930 participants 48 to 97 years old with advanced prostate cancer.

[18] The trial was conducted at 155 sites in the United States, Canada, and countries in South America, Europe and the Asia Pacific region.

[18] The efficacy of relugolix was assessed by the percentage of participants who achieved and maintained low testosterone level equal to castration.

[12][13][7][5] Relugolix compounded with ethinyl estradiol and norethindrone is sold under the brand name Myfembree for the treatment of uterine fibroids.

[22] Relugolix was approved for medical use in the European Union in April 2022,[6][23] and in the United Kingdom in July 2022[24] (although not available in NHS England until August 2024[25]).