Exhibit 99.3
You invested in GH RESEARCH PLC and it’s time to vote! You have the right to
vote on proposals being presented at the Annual Meeting. This is an important notice regarding the availability of proxy material for the shareholder meeting to be held on July 31, 2025. Get informed before you vote View the Notice of
Annual General Meeting, Irish Statutory Financial Statements, Form 20-F online OR you can receive a free paper or email copy of the material(s) by requesting prior to July 17, 2025. If you would like to request a copy of the material(s) for
this and/or future shareholder meetings, you may (1) visit www.ProxyVote.com, (2) call 1-800-579-1639 or (3) send an email to sendmaterial@proxyvote.com. If sending an email, please include your control number (indicated below) in the subject
line. Unless requested, you will not otherwise receive a paper or email copy. *If you choose to vote these shares in person at the meeting, you must request a “legal proxy.” To do so, please follow the instructions at www.ProxyVote.com or
request a paper copy of the materials, which will contain the appropriate instructions. Please check the meeting materials for any special requirements for meeting attendance. Smartphone users Point your camera here and vote without
entering a control number Your Vote Counts! FLASHID-JOB# For complete information and to vote, visit www.ProxyVote.com Control # Ricky Campana P.O. Box 123456 Suite 500 51 Mercedes Way Edgewood, NY 11717 1
OF 322,224 148,294 2 30# Hextone, Inc. P.O. Box 9142 Farmingdale, NY 11735 XXXX XXXX XXXX XXXX GH RESEARCH PLC 2025 Annual Meeting Vote by July 30, 2025 11:59 PM ET Vote in Person at the Meeting* July 31, 2025 2:00 PM
LST Joshua Dawson House Dawson Street Dublin 2, D02 RY95 Ireland
Voting Items Board Recommends 1. Election of Directors Nominees: 1A Florian
Schonharting For 1B Michael Forer, LL.B. For 1C Dermot Hanley For 1D Duncan Moore, PhD For 2. To ratify the appointment of PricewaterhouseCoopers Ireland as independent auditors of the Company for the year ending 31 December 2025 and
to authorise the Board to fix the remuneration of the auditors. For 3. To renew the Boards existing authority under Irish law to allot and issue ordinary shares. For 4. To renew the Boards existing authority under Irish law to allot and
issue ordinary shares for cash without first offering those shares to existing shareholders pursuant to the statutory pre-emption right that would otherwise apply. For NOTE: Such other business as may properly come before the meeting or any
adjournment thereof. THIS IS NOT A VOTABLE BALLOT This is an overview of the proposals being presented at the upcoming shareholder meeting. Please follow the instructions on the reverse side to vote these important matters. Vote at
www.ProxyVote.com FLASHID-JOB# Control # XXXX XXXX XXXX XXXX 1.00000 322,224 148,294 Under New York Stock Exchange rules, brokers may vote “routine” matters at their discretion if your voting instructions are not communicated to us at
least 10 days before the meeting. We will nevertheless follow your instructions, even if the broker’s discretionary vote has already been given, provided your instructions are received prior to the meeting date. GH RESEARCH PLC 2025 Annual
Meeting Vote by July 30, 2025 11:59 PM ET