Company: GHRS
Filing Date: 2025-02-05
Form Type: 424B5
Source: 0001140361-25-003183
Chunk: 3

Company: GH Research PLC
Filing Date: 2025-02-05
Form: 424B5
Chunk 3
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 data presented in this prospectus supplement, accompanying prospectus and documents incorporated by reference, our estimates involve risks and uncertainties and are subject to change based on various factors, including those discussed under the heading “Risk Factors” in this prospectus supplement and in the accompanying prospectus, and under similar headings in the other documents that are incorporated herein or therein by reference.

Unless otherwise indicated or the context otherwise requires, all references in this prospectus supplement, the accompanying prospectus and documents incorporated by reference to “GH Research” or the “Company,” “we,” “our,” “ours,” “us” or similar terms refer to GH Research PLC, together with its consolidated subsidiary. The terms “dollar,” “U.S. Dollar,” “US$” and “$” refer to the lawful currency of the United States. References to our “ordinary shares” or “shares” refer to our ordinary shares, nominal value $0.025 per share. References to our “2023 Annual Report” refer to our Annual Report on Form 20-F for the year ended December 31, 2023 , filed with the SEC on March 7, 2024.

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#### TABLE OF CONTENTS

### PROSPECTUS SUPPLEMENT SUMMARY

### Business Overview
We are a clinical-stage biopharmaceutical company dedicated to transforming the treatment of psychiatric and neurological disorders. Our initial focus is on developing our novel and proprietary mebufotenin therapies for the treatment of patients with treatment-resistant depression (TRD).

Our portfolio currently includes GH001, our proprietary inhalable mebufotenin product candidate and GH002, our proprietary intravenous mebufotenin product candidate. While GH001 is currently delivered via a vaporization device produced by a third party, we are developing a proprietary aerosol delivery device, which is currently in clinical investigation. We have completed two Phase 1 healthy volunteer clinical trials for GH001 (GH001-HV-101 and GH001-HV-103), in which administration of GH001 via inhalation was observed to be well tolerated at the investigated single dose levels and in an individualized dosing regimen (IDR), with intra-subject dose escalation within a single day. We have also completed a Phase 1/2 clinical trial in patients with TRD (GH001-TRD-102) and have recently completed the double-blind phase of a randomized, double-blind, placebo-controlled phase 2b trial in patients with TRD (GH001-TRD