Orilissa is an oral gonadotropin-releasing hormone (GnRH) antagonist used to manage moderate to severe pain from endometriosis. It works by suppressing ovarian hormone production, particularly estrogen, which helps reduce endometrial tissue activity. Common side effects include hot flashes, mood changes, and reduced bone density with long-term use. Orilissa is typically prescribed when hormonal birth control or surgery is ineffective or not preferred.