424B5 1 ny20073175x1_424b5.htm 424B5

Filed Pursuant to Rule 424(b)(5)

Registration No. 333-285310

PROSPECTUS SUPPLEMENT

(to Prospectus dated March 7, 2025)

Up to $200,000,000

Ordinary Shares

GH Research PLC

We have entered into an At-the-Market Equity Offering Sales Agreement with Stifel, Nicolaus & Company, Incorporated (the “Agent”), dated May 14, 2026 (the “Sales Agreement”), relating to the sale of our ordinary shares offered by this prospectus supplement and the accompanying prospectus. In accordance with the terms of the Sales Agreement, under this prospectus supplement and accompanying prospectus we may offer and sell up to $200,000,000 of our ordinary shares, nominal value $0.025 per share, from time to time through the Agent, acting as sales agent or principal.

Our ordinary shares are listed on the Nasdaq Global Market (Nasdaq) under the symbol “GHRS.” On May 12, 2026, the last reported sale price of our ordinary shares on Nasdaq was $21.54 per share.

Sales of our ordinary shares, if any, under this prospectus supplement and the accompanying prospectus will be made by any method permitted that is deemed an “at the market offering” as defined in Rule 415(a)(4) under the Securities Act of 1933, as amended (the “Securities Act”). The Agent is not required to sell any specific amount, but will act as our sales agent using commercially reasonable efforts consistent with its normal trading and sales practices. There is no arrangement for funds to be received in any escrow, trust or similar arrangement.

The Agent will be entitled to compensation at a commission rate of up to 3.0% of the gross sales price per share sold. In connection with the sale of the ordinary shares on our behalf, the Agent will be deemed to be an “underwriter” within the meaning of the Securities Act and the compensation of the Agent will be deemed to be underwriting commissions or discounts. We have also agreed to provide indemnification and contribution to the Agent with respect to certain liabilities, including liabilities under the Securities Act. See “Plan of Distribution” beginning on page S-16 for additional information regarding the compensation to be paid to the Agent.

Investing in our ordinary shares involves risks. See the section titled “Risk Factors” on page S-5 of this prospectus supplement and in the documents we incorporate by reference herein.

Neither the Securities and Exchange Commission nor any state or other securities commission, has approved or disapproved of our securities or passed upon the adequacy or accuracy of this prospectus supplement. Any representation to the contrary is a criminal offense.

The date of this Prospectus Supplement is May 14, 2026


			Page
About This Prospectus Supplement			S-1
Prospectus Supplement Summary			S-3
The Offering			S-4
Risk Factors			S-5
Cautionary Statement Regarding Forward-Looking Statements			S-6
Dilution			S-7
Use of Proceeds			S-8
Taxation			S-9
Plan of Distribution			S-16
Legal Matters			S-17
Experts			S-17
Service of Process and Enforcement of Liabilities			S-17
Where You Can Find More Information			S-17
Incorporation of Certain Documents by Reference			S-18


About this Prospectus			1
Our Company			3
Risk Factors			5
Cautionary Statement Regarding Forward-Looking Statements			6
Use of Proceeds			7
Description of Share Capital and Constitution			8
Comparison of Irish Law and Delaware Law			18
Description of Debt Securities			33
Description of Warrants			33
Description of Units			33
Description of Subscription Rights			33
Forms of Securities			34
Plan of Distribution			36
Expenses			38
Legal Matters			38
Experts			38
Service of Process and Enforcement of Liabilities			39
Where You Can Find More Information			40
Information Incorporated by Reference			41


	IRELAND	DELAWARE
Number of Directors	The Irish Companies Act provides for a minimum of two directors. The Constitution provides for a minimum of two directors and a maximum of nine. Our shareholders may from time to time increase or reduce the maximum number, or increase the minimum number, of directors by ordinary resolution. Our Board of Directors determines the number of directors within the range of two to nine.	A typical certificate of incorporation and bylaws would provide that the number of directors on the board of directors will be fixed from time to time by a vote of the majority of the authorized directors. Under Delaware law, a board of directors can be divided into classes and cumulative voting in the election of directors is only permitted if expressly authorized in a corporation’s certificate of incorporation.

Removal of Directors	Under the Irish Companies Act, the shareholders may, by ordinary resolution, remove a director from office before the expiration of his or her term, at a meeting held with no less than 28 days’ notice and at which the director is entitled to be heard. Because of this provision of the Irish Companies Act, a director may be so removed before the expiration of his or her period of office. The power of removal is without prejudice to any claim for damages for breach of contract (e.g., employment contract) that the director may have against the Company in respect of his or her removal. The Constitution also provides that the office of a director will also be vacated if the director is restricted or disqualified to act as a director under the Irish Companies Act; resigns his or her office by notice in writing to us or in writing offers to resign and the directors resolve to accept such offer; or is requested to resign in writing by not less than 75% of the other directors.	A typical certificate of incorporation and bylaws provide that, subject to the rights of holders of any preferred shares, directors may be removed at any time by the affirmative vote of the holders of at least a majority, or in some instances a supermajority, of the voting power of all of the then outstanding shares entitled to vote generally in the election of directors, voting together as a single class. A certificate of incorporation could also provide that such a right is only exercisable when a director is being removed for cause (removal of a director only for cause is the default rule in the case of a classified board).

Vacancies on the Board of Directors	Any vacancy on our Board of Directors, including a vacancy resulting from an increase in the number of directors or from the death, resignation, retirement,	A typical certificate of incorporation and bylaws provide that, subject to the rights of the holders of any preferred shares, any vacancy, whether arising through death,


	IRELAND	DELAWARE
	disqualification or removal of a director, shall be deemed a casual vacancy. Any casual vacancy shall only be filled by the decision of a majority of our Board of Directors then in office, provided that a quorum is present and provided that the appointment does not cause the number of directors to exceed any number fixed by or in accordance with the Constitution as the maximum number of directors. Any director elected to fill a vacancy resulting from an increase in the number of directors shall hold office for the remaining term of office. Any director elected to fill a vacancy not resulting from an increase in the number of directors shall have the same remaining term as that of his predecessor. A director retiring at a meeting shall retain office until the close or adjournment of the meeting.	resignation, retirement, disqualification, removal, an increase in the be filled by a majority vote of the remaining directors, even if such directors remaining in office constitute less than a quorum, or by the sole remaining director. Any newly elected director usually holds office for the remainder of the full term expiring at the annual meeting of shareholders at which the term of the class of directors to which the newly elected director has been elected expires.

Annual General Meeting	We are required to hold annual general meetings at intervals of no more than 15 months after the previous annual general meeting, provided that an annual general meeting is held in each calendar year following our first annual general meeting, no more than nine months after our fiscal year-end. The only matters which must, as a matter of Irish company law, be transacted at an annual general meeting are the consideration of the Irish statutory financial statements, the report of the directors, the report of the auditors on those statements and that report and a review by the members of our affairs. If no resolution is made in respect of the reappointment of an auditor at an annual general meeting, the previous auditor will be deemed to have continued in office.	Typical bylaws provide that annual meetings of shareholders are to be held on a date and at a time fixed by the board of directors.

General Meeting	Our extraordinary general meetings may be convened by (i) our Board of Directors, (ii) on requisition of shareholders holding not less than 10% of our paid up share capital carrying voting rights or (iii) on requisition of our auditors. Extraordinary general meetings are generally held for the purposes of approving shareholder resolutions as may be required from time to time.	Under Delaware law, a special meeting of shareholders may be called by the board of directors or by any other person authorized to do so in the certificate of incorporation or the bylaws.


	IRELAND	DELAWARE
	If our directors become aware that our net assets are half or less of the amount of our called up share capital, our directors must convene an extraordinary general meeting of our shareholders not later than 28 days from the date that they learn of this fact. This meeting must be convened for the purposes of considering whether any, and if so what, measures should be taken to address the situation.

Notice of General Meetings	Notice of a general meeting must be given to all our shareholders and to our auditors. The minimum notice periods are 21 clear days’ notice in writing for an annual general meeting or an extraordinary general meeting to approve a special resolution and 14 clear days’ notice in writing for any other extraordinary general meeting (if the company offers facilities to members to vote by electronic means and shareholders have passed a special resolution at the immediately preceding general meeting approving such shortened notice period). General meetings may be called by shorter notice, but only with the consent of our auditors and all of our shareholders entitled to attend and vote thereat. Because of the 21-clear day and 14-clear day requirements described in this paragraph, the Constitution includes provisions reflecting these requirements of Irish law. In the case of an extraordinary general meeting convened by our shareholders, the proposed purpose of the meeting must be set out in the requisition notice. Upon receipt of this requisition notice, our Board of Directors has 21 days to convene a meeting of our shareholders to vote on the matters set out in the requisition notice. This meeting must be held within two months of the receipt of the requisition notice. If our Board of Directors does not convene the meeting within such 21-day period, the requisitioning shareholders, or any of them representing more than one-half of the total voting rights of all of them, may themselves convene a meeting, which meeting must be held within three months of the receipt of the requisition notice.	Under Delaware law, unless otherwise provided in the certificate of incorporation or bylaws, written notice of any meeting of the stockholders must be given to each stockholder entitled to vote at the meeting not less than 10 nor more than 60 days before the date of the meeting and shall specify the place, date, hour and purpose or purposes of the meeting.

Quorum	The presence, in person or by proxy, of one or more persons holding or representing by proxy at least 25% of the votes that may be	Under Delaware law, a corporation’s certificate of incorporation or bylaws can specify the number of shares which constitute


	IRELAND	DELAWARE
	cast at the relevant time constitutes a quorum for the conduct of business at a general meeting. No business may take place at a general meeting if a quorum is not present in person or by proxy. Our Board of Directors has no authority to waive quorum requirements stipulated in the Constitution. Abstentions and broker non-votes will be counted as present for purposes of determining whether there is a quorum in respect of the proposals	the quorum required to conduct business at a meeting, provided that in no event shall a quorum consist of less than one-third of the shares entitled to vote at a meeting.

Proxy	Under Irish law, a shareholder may designate another person to attend, speak and vote at a general meeting of the company on their behalf by proxy, which proxy need not be a shareholder. Where interests in shares are held by a nominee trust company, this company may exercise the rights of the beneficial holders on their behalf as their proxy. Voting rights may be exercised by shareholders registered in the share register as of the record date for the meeting or by a duly appointed proxy of such a registered shareholder, which proxy need not be a shareholder. Where interests in shares are held by a nominee trust company, this company may exercise the rights of the beneficial holders on their behalf as their proxy. All proxies must be appointed in accordance with the Constitution. The Constitution permits the appointment of proxies by our shareholders to be notified to us electronically, when permitted by our directors.	Under Delaware law, at any meeting of stockholders, a stockholder may designate another person to act for such stockholder by proxy, but no such proxy shall be voted or acted upon after three years from its date, unless the proxy provides for a longer period. A director of a Delaware corporation may not issue a proxy representing the director’s voting rights as a director.

Issue of New Shares	Under the Constitution, we may issue shares subject to the maximum authorized share capital contained in the Constitution. The authorized share capital may be increased or reduced by a resolution approved by a simple majority of the votes cast at a general meeting of our shareholders, referred to under Irish law as an “ordinary resolution.” As a matter of Irish law, the directors of a company may issue new ordinary shares without shareholder approval once authorized to do so by its constitution or by an ordinary resolution adopted by its shareholders at a general meeting. The authorization may be granted for a maximum period of five years, at which point it may be renewed by shareholders by an	Under Delaware law, if the company’s certificate of incorporation so provides, the directors have the power to authorize the issuance of additional stock. The directors may authorize capital stock to be issued for consideration consisting of cash, any tangible or intangible property or any benefit to the company or any combination thereof.


	IRELAND	DELAWARE
	ordinary resolution. Accordingly, the Constitution authorizes our Board of Directors to issue new ordinary shares without shareholder approval for a period of five years from the date of the adoption of the Constitution.

Preemptive Rights	Under Irish law, unless otherwise authorized, when an Irish public limited company issues shares for cash to new shareholders, it is required first to offer those shares on the same or more favorable terms to existing shareholders of the company on a pro rata basis, commonly referred to as the statutory preemption right. However, we have opted out of these preemption rights in the Constitution as permitted under Irish law. Because Irish law permits this opt-out to last for a maximum of five years, the Constitution provides that this opt-out will lapse five years after the adoption of the Constitution. Such opt-out may be renewed by a special resolution of the shareholders. A special resolution requires not less than 75% of the votes cast at a general meeting of our shareholders. If the opt-out is not renewed, shares issued for cash must be offered to our preexisting shareholders pro rata before the shares can be issued to any new shareholders. The statutory preemption rights do not apply where shares are issued for non-cash consideration and do not apply to the issue of non-equity shares (that is, shares that have the right to participate only up to a specified amount in any income or capital distribution) or where shares are issued pursuant to an employee option or similar equity plan.	Under Delaware law, stockholders have no preemptive rights to subscribe to additional issues of stock or to any security convertible into such stock unless, and except to the extent that, such rights are expressly provided for in the certificate of incorporation.

Authority to Allot	Under the Constitution, we may issue shares subject to the maximum authorized share capital contained in the Constitution. The authorized share capital may be increased or reduced by a resolution approved by a simple majority of the votes cast at a general meeting of our shareholders, referred to under Irish law as an “ordinary resolution.” Our authorized share capital may be divided into shares of such nominal value as the resolution shall prescribe. As a matter of Irish law, the directors of a company may issue new ordinary shares without shareholder approval once authorized to do so by its constitution or by an ordinary resolution adopted by its shareholders at a general meeting.	Under Delaware law, if the corporation’s charter or certificate of incorporation so provides, the board of directors has the power to authorize the issuance of stock. The board may authorize capital stock to be issued for consideration consisting of cash, any tangible or intangible property or any benefit to the corporation or any combination thereof. It may determine the amount of such consideration by approving a formula. In the absence of actual fraud in the transaction, the judgment of the directors as to the value of such consideration is conclusive.


	IRELAND	DELAWARE
	was passed. The person whose shares of ours are to be bought cannot vote in favor of the special resolution and, for at least 21 days prior to the special resolution being passed, the purchase contract must be on display or must be available for inspection by our shareholders at our registered office.

Different Classes of Shares	Without prejudice to any rights attached to any existing shares, we may issue shares with such rights or restrictions as we determine by an ordinary resolution approved by our shareholders. As a matter of Irish company law, the directors of a company may issue new ordinary shares without shareholder approval once authorized to do so by the constitution or by an ordinary resolution adopted by the shareholders at a general meeting. The authorization may be granted for a maximum period of five years, at which point it must be renewed by the shareholders by an ordinary resolution (if we wish to issue shares). The Constitution authorizes our Board of Directors to issue new ordinary shares without shareholder approval for a period of five years from the date of adoption of our Constitution. We may also issue shares which are, or are liable to be, redeemed at the option of us or the holder. Whenever our share capital is divided into different classes of shares, the special rights attached to any class may be varied or abrogated either with the written consent of the holders of 75% in nominal value of the issued shares of the class (excluding shares held as treasury shares) or with the sanction of a special resolution passed at a separate meeting of the holders of the shares of the class (but not otherwise), and may be so varied or abrogated either while we are a going concern or during or in contemplation of a winding up. The rights conferred upon the holders of any class of shares issued with preferred or other rights shall not, unless otherwise expressly provided by the terms of issue of the shares of that class, be deemed to be varied by our purchase or redemption of our own shares or by the creation or issue of further shares ranking pari passu therewith or subordinate thereto.	A company’s Delaware’s certificate of incorporation may authorize the board of directors: (1) to provide for the issuance of one or more series of preferred stock; (2) to establish from time to time the number of shares to be included in such series; and (3) to fix the designations, preferences and relative, participating, optional or other special rights, and qualifications, limitations or restrictions of each such series.

Dividends	Under Irish law, dividends and distributions may only be made from distributable reserves	Under Delaware law, subject to any restriction in the corporation’s certificate of


	IRELAND	DELAWARE
	which are, generally, a company’s accumulated realized profits less its accumulated realized losses. In addition, no distribution or dividend may be made if our net assets are not, or if making such distribution or dividend will cause our net assets to not be, equal to, or in excess of, the aggregate of our called up share capital plus undistributable reserves. Undistributable reserves include the company’s undenominated capital and the amount by which a company’s accumulated unrealized profits exceeds its accumulated unrealized losses. The determination as to whether or not we have sufficient distributable reserves to fund a dividend must be made by reference to our most recent unconsolidated annual audited financial statements or other financial statements properly prepared in accordance with the Irish Companies Act. The relevant financial statements must be filed in the Companies Registration Office (the official public registry for companies in Ireland). The Constitution authorizes our Board of Directors to declare an interim dividend without shareholder approval to the extent they appear justified by profits of the Company available for distribution. Our Board of Directors may also recommend a dividend to be approved and declared by the shareholders at a general meeting, provided that no dividend issued may exceed the amount recommended by the directors.	incorporation, the Board may declare and pay dividends out of: (1) surplus of the corporation, which is defined as net assets less statutory capital; or (2) if no surplus exists, out of the net profits of the corporation for the year in which the dividend is declared and/or the preceding year; provided, however, that if the capital of the corporation has been diminished to an amount less than the aggregate amount of capital represented by the issued and outstanding stock of all classes having preference upon the distribution of assets, the Board may not declare and pay dividends out of the corporation’s net profits until the deficiency in the capital has been repaired.

General Provisions Governing a Liquidation; Liquidation Distributions	Our duration will be unlimited. We may be dissolved and wound up at any time by way of a shareholders’ voluntary winding up or a creditors’ winding up. In the case of a shareholders’ voluntary winding up, a special resolution of our shareholders is required. We may also be dissolved by way of court order on the application of a creditor, or by the Companies Registration Office as an enforcement measure where we have failed to file certain returns. The rights of the shareholders to a return of our assets on dissolution or winding up, following the settlement of all claims of creditors, are prescribed in the Constitution.	Upon the dissolution of a Delaware corporation, after satisfaction of the claims of creditors, the assets of that corporation would be distributed to stockholders in accordance with their respective interests, including any rights a holder of shares of preference shares may have to preferred distributions upon dissolution or liquidation of the corporation.


	IRELAND	DELAWARE
Amendment of Constitution	Irish company law requires a special resolution of our shareholders (approval by not less than 75% of the votes cast at a general meeting of our shareholders) to approve any amendments to the Constitution.	Amendment of Certification of Incorporation and Bylaws Under Delaware law, amendments to a corporation’s certificate of incorporation require the approval of stockholders holding a majority of the outstanding shares entitled to vote on the amendment. If a class vote on the amendment is required by the Delaware General Corporation Law, a majority of the outstanding stock of the class is required, unless a greater proportion is specified in the certificate of incorporation or by other provisions of the Delaware General Corporation Law. Under the Delaware General Corporation Law, the board of directors may amend bylaws if so authorized in the certificate of incorporation. The stockholders of a Delaware corporation also have the power to amend bylaws.

Reduction of Share Capital	We may reduce our authorized but unissued share capital in any manner permitted by the Irish Companies Act. We also may, by special resolution (approved by not less than 75% of the votes cast at a general meeting of our shareholders) and subject to confirmation by the Irish High Court, reduce our issued share capital in any way permitted by the Irish Companies Act. For purposes of Irish law, repurchases of our shares may be effected by a redemption if the repurchased shares are redeemable shares or are deemed to be redeemable shares by the Constitution. The Constitution provides that, unless the Board of Directors determines otherwise, each of our shares shall be deemed to be a redeemable share on, and from the time of, the existence or creation of an agreement, transaction or trade between us and any person pursuant to which we acquire or will acquire our shares, or an interest in our shares, from the relevant person. Redeemable shares of ours shall have the same characteristics as any other of our shares save that they shall be redeemable in accordance with the arrangement.	Under Delaware law, a corporation, by an affirmative vote of a majority of the board of directors, may reduce its capital by reducing or eliminating the capital represented by shares of capital stock which have been retired, by applying to an already authorized purchase redemption, conversion or exchange of outstanding shares of its capital stock some or all of the capital represented by shares being purchased, redeemed, converted or exchanged or any capital that has not been allocated to any particular class of capital stock or by transferring to surplus capital some or all of the capital not represented by any particular class of its capital stock or the capital associated with certain issued shares of its par value capital stock. No reduction of capital may be made unless the assets of the corporation remaining after the reduction are sufficient to pay any debts for which payment has not otherwise been provided.


	IRELAND	DELAWARE
	action in respect of such costs or liability, or where an Irish court grants relief because the director or company secretary acted honestly and reasonably and ought fairly to be excused. Any provision whereby an Irish company seeks to commit in advance to indemnify its directors or company secretary over and above the limitations imposed by the Irish Companies Act will be void, whether contained in its Constitution or any contract between the company and the director or company secretary. This restriction does not apply to our executive officers who are not directors, our company secretary or other persons who would be considered “officers” within the meaning of the Irish Companies Act. The Constitution also contains indemnification and expense advancement provisions for persons who are not directors or our corporate secretary. We are permitted under the Constitution and the Irish Companies Act to take out directors’ and officers’ liability insurance, as well as other types of insurance, for our directors, officers, employees and agents. In order to attract and retain qualified directors and officers, we maintain customary directors’ and officers’ liability insurance and other types of comparable insurance.	(2) a director or officer for acts or omissions not in good faith or which involve intentional misconduct or a knowing violation of law; (3) a director for intentional or negligent payment of unlawful dividends or stock purchases or redemptions; (4) a director or officer for any transaction from which he or she derived an improper personal benefit; or (5) an officer in any action by or in right of the corporation.

Voting Rights	Under the Constitution, each holder of our ordinary shares is entitled to one vote for each ordinary share that he or she holds as of the record date for the meeting. We may not exercise any voting rights in respect of any shares held as treasury shares. Any shares held by our subsidiaries will count as treasury shares for this purpose, and such subsidiaries cannot therefore exercise any voting rights in respect of those shares.	Each stockholder is entitled to one vote for each share of capital stock held by the stockholder, unless the certificate of incorporation provides otherwise. If issued, the voting rights of holders of preferred stock will be determined by the certificate of incorporation or the certificate of designation with respect to such preferred stock.

Shareholder Vote on Certain Transactions	Pursuant to Irish law, shareholder approval in connection with a transaction involving the Company would be required under the following circumstances: • in connection with a scheme of arrangement, both a court order from the Irish High Court and the approval of a majority in number representing 75% in value of the shareholders present and	Generally, under Delaware law, unless the certificate of incorporation provides for the vote of a larger portion of the stock, completion of a merger, consolidation, sale, lease or exchange of all or substantially all of a corporation’s assets or dissolution requires: the approval of the board of directors; and the approval by the vote of the holders of a majority of the outstanding stock or, if the certificate of incorporation provides for more


Expense			Amount
SEC registration fee			$58,209.50
Printing and engraving expenses			(1)
Legal fees and expenses			(1)
Accounting fees and expenses			(1)
Miscellaneous fees and expenses			(1)
Total			$⁽¹⁾

The authorization may be granted for a maximum period of five years, at which point it may be renewed by shareholders by an ordinary resolution. Accordingly, the Constitution authorizes our Board of Directors to issue new ordinary shares without shareholder approval for a period of five years from the date of the adoption of the Constitution.

Acquisition of Own Shares

Under Irish law, a company may issue redeemable shares and redeem them out of distributable reserves or the proceeds of a new issue of shares for that purpose. All redeemable shares must also be fully paid. Redeemable shares may, upon redemption, be cancelled or held in treasury. The Constitution provides that shareholder approval will not be required to deem any shares redeemable. We may also be given an additional general authority by our shareholders to purchase our own shares on-market, which would take effect on the same terms and be subject to the same conditions as applicable to purchases by our subsidiaries as described below.

Repurchased and redeemed shares may be cancelled or held as treasury shares. The nominal value of treasury shares that we hold at any time must not exceed 10% of the nominal value of our issued share capital. We may not exercise any voting rights in respect of any shares held as treasury shares. We may either cancel or, subject to certain conditions, reissue treasury shares.

Under Irish law, an Irish or non-Irish subsidiary may purchase our shares either on-market or off-market. For a subsidiary of ours to make on-market purchases of our shares, the shareholders must provide general authorization for such purchase by way of ordinary resolution. However, as long as this general authority has been granted, no specific shareholder authority for a particular on-market purchase by a subsidiary of our shares is required. For an off-market purchase by a subsidiary of ours, the proposed purchase contract must be authorized by special resolution of our shareholders before the contract is entered into. This authority must specify the date on which the authority is to expire, which shall not be more than 18 months from the date the special resolution

Under Delaware law, any corporation may purchase or redeem its own shares, except that generally it may not purchase or redeem these shares if the capital of the corporation is impaired at the time or would become impaired as a result of the redemption. A corporation may, however, purchase or redeem out of capital shares that are entitled upon any distribution of its assets to a preference over another class or series of its shares if the shares are to be retired and the capital reduced.