Exhibit 4.3

EXECUTION VERSION

COUNTERPART AGREEMENT

This COUNTERPART AGREEMENT, dated April 21, 2022 (this “Counterpart Agreement”) is delivered pursuant to that certain Credit and Guaranty Agreement, dated November 15, 2019 (as amended prior to the date hereof and as it may be further amended, supplemented or otherwise modified, the “Credit Agreement”; the terms defined therein and not otherwise defined herein being used herein as therein defined), by and among Grifols Worldwide Operations Limited, a private company validly incorporated and existing under the laws of Ireland (the “Foreign Borrower”), Grifols Worldwide Operations USA, Inc., a Delaware corporation (the “U.S. Borrower”), Grifols, S.A., a sociedad anónima organized under the laws of the Kingdom of Spain (the “Spanish Borrower” and the “Parent” and, together with the Foreign Borrower and the U.S. Borrower, the “Borrowers”), as a Guarantor and the Spanish Borrower, and certain Subsidiaries of the Parent, as Guarantors, the Lenders party thereto from time to time, and Bank of America, N.A., as Administrative Agent (together with its permitted successors in such capacity, the “Administrative Agent”) and as Collateral Agent (together with its permitted successors in such capacity, the “Collateral Agent”).

Section 1. Pursuant to Section 5.12 of the Credit Agreement, the undersigned hereby:

(a)agrees that this Counterpart Agreement may be attached to the Credit Agreement and that by the execution and delivery hereof, the undersigned becomes a Guarantor under the Credit Agreement and agrees to be bound by all of the terms thereof;

(b)represents and warrants that each of the representations and warranties set forth in the Credit Agreement and each other Loan Document and applicable to the undersigned is true and correct both before and after giving effect to this Counterpart Agreement, except to the extent that any such representation and warranty relates solely to any earlier date, in which case such representation and warranty is true and correct as of such earlier date;

(c)no event has occurred or is continuing as of the date hereof, or will result from the transactions contemplated hereby on the date hereof, that would constitute an Event of Default or a Default;

(d)agrees, to irrevocably, unconditionally, jointly and severally with the other Guarantors, to guaranty the due and punctual payment in full of all Obligations when the same shall become due, whether at stated maturity, by required prepayment, declaration, acceleration, demand or otherwise (including amounts that would become due but for the operation of the automatic stay under Section 362(a) of the Bankruptcy Code, 11 U.S.C. § 362(a)) and in accordance with Article VII of the Credit Agreement; and

(e)the undersigned hereby agrees that a counterpart signature page of this Counterpart Agreement may be attached to that certain Master Intercompany Note Number 3, dated as of November 15, 2019, by and among the Parent and certain of its subsidiaries (the “Master Intercompany Note”) and that hereinafter, the undersigned shall be deemed an “Additional Party”, “Payor” and “Payee” under, and in each case, as defined in, the Master Intercompany Note.

Section 2. The undersigned agrees from time to time, upon request of Administrative Agent, to take such additional actions and to execute and deliver such additional documents and instruments as Administrative Agent may request to effect the transactions contemplated by, and to carry out the intent of, this Counterpart Agreement. Neither this Counterpart Agreement nor any term hereof may be changed, waived, discharged or terminated, except by an instrument in writing signed by the party (including, if applicable, any party required to evidence its consent to or acceptance of this Counterpart Agreement) against whom enforcement of such change, waiver, discharge or termination is sought. Any notice or other communication herein required or permitted to be given shall be given pursuant to Section 10.01 of the Credit Agreement, and for all purposes thereof, the notice address of the undersigned shall be the address as set forth on the signature page hereof. In case any provision in or obligation under this Counterpart Agreement shall be invalid, illegal or unenforceable in any jurisdiction, the validity, legality and

enforceability of the remaining provisions or obligations, or of such provision or obligation in any other jurisdiction, shall not in any way be affected or impaired thereby.

This Counterpart Agreement may be executed by one or more of the parties to this Counterpart Agreement on any number of separate counterparts, and all of said counterparts taken together shall be deemed to constitute one and the same instrument. Delivery of an executed signature page of this Counterpart Agreement by e-mail or facsimile transmission shall be effective as delivery of a manually executed counterpart hereof. The words “execution”, “signed”, “signature”, “delivery” and words of like import in or relating to this Counterpart Agreement shall be deemed to include Electronic Signatures (as defined below), deliveries or the keeping of records in electronic form, each of which shall be of the same legal effect, validity or enforceability as a manually executed signature, physical delivery thereof or the use of a paper-based recordkeeping system, as the case may be. “Electronic Signatures” means any electronic symbol or process attached to, or associated with, any contract or other record and adopted by a person with the intent to sign, authenticate or accept such contract or record. A complete set of counterparts shall be lodged with the Parent and the Administrative Agent.

THIS COUNTERPART AGREEMENT AND THE RIGHTS AND OBLIGATIONS OF THE PARTIES HEREUNDER SHALL BE GOVERNED BY, AND SHALL BE CONSTRUED AND ENFORCED IN ACCORDANCE WITH, THE LAWS OF THE STATE OF NEW YORK.

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IN WITNESS WHEREOF, the undersigned has caused this Counterpart Agreement to be duly executed and delivered by its duly authorized officer as of the date above first written.

	GRIFOLS ESCROW ISSUER, S.A.U.
By:	ALFREDO ARROYO
Name:	ALFREDO ARROYO
Title	CFO
Address for Notices:
Avinguda de la Generalitat, 152-158
Pare de Negocis Can Sant Joan
Sant Cugat del Valles
08174 Barcelona Spain
Attention: Alfredo Arroyo
Email: alfredo.arroyo@grifols.com
With a copy to:
Proskauer Rose LLP
11 Times Square
New York, New York
Attention: Carlos E. Martinez
Email : CMartinez@proskauer.com

[Signature Page to Counterpart Agreement]

ACKNOWLEDGED AND ACCEPTED,
as of the date above first written:
BANK OF AMERICA, N.A.,
as Administrative Agent and Collateral Agent
By:	Angela Larkin
Name:	Angela Larkin
Title:	Vice President

[Signature Page to Counterpart Agreement]