GH Research is a clinical-stage biopharmaceutical company developing mebufotenin-based therapies for treatment-resistant depression (TRD) — broadly defined as depression that fails to respond to two or more prior pharmacotherapies. The company has no approved products or revenue. GH Research's lead asset, GH001, is an inhaled formulation of mebufotenin designed to be administered in a single supervised clinic visit, without mandatory psychotherapy sessions. In a completed Phase 2b trial in TRD patients, GH001 met its primary endpoint, with the majority of treated patients achieving remission within hours of dosing and 73% of patients in a 6-month extension remaining in remission. GH Research contrasts this profile with esketamine (Janssen's SPRAVATO), the primary approved TRD pharmacotherapy, which requires roughly 40 clinic visits per year. GH Research is developing a proprietary aerosol delivery device required for its pivotal Phase 3 program, which the company expects to initiate in 2026 following a U.S. clinical hold that was lifted in December 2025. The company also has GH002, an IV formulation of mebufotenin, in earlier development. If approved, GH Research plans to commercialize GH001 directly in the U.S. and major European markets through certified treatment centers. A key hurdle: mebufotenin is currently a Schedule I controlled substance in the U.S., requiring DEA rescheduling before commercialization and Medicare/Medicaid reimbursement would be possible. GH Research is incorporated in Ireland and funds itself through capital raises.