Exhibit 4.3

AMENDMENT NO. 1 TO

SUPPLEMENTAL INDENTURE NO. 11

by and between

WELLTOWER INC.

and

THE BANK OF NEW YORK MELLON TRUST COMPANY, N.A.

As of October 19, 2015

SUPPLEMENTAL TO THE INDENTURE DATED AS OF MARCH 15, 2010

WELLTOWER INC.

4.000% Notes due 2025

This AMENDMENT NO. 1 TO SUPPLEMENTAL INDENTURE NO. 11 (this “Amendment No. 1”) is made and entered into as of October 19, 2015 between WELLTOWER INC., a Delaware corporation formerly known as Health Care REIT, Inc. (the “Company”), and THE BANK OF NEW YORK MELLON TRUST COMPANY, N.A., a national banking association duly organized and existing under the laws of the United States of America, as Trustee (the “Trustee”).

WITNESSETH THAT:

WHEREAS, the Company and the Trustee have executed and delivered an Indenture, dated as of March 15, 2010 (as amended, supplemented or otherwise modified from time to time, the “Base Indenture” and, together with Supplemental Indenture No. 11 dated as of May 26, 2015 (“Supplemental Indenture No. 11”), as amended by this Amendment No. 1 and as further amended, supplemented or otherwise modified from time to time, the “Indenture”) to provide for the future issuance of the Company’s senior debt securities (the “Securities”) to be issued from time to time in one or more series; and

WHEREAS, pursuant to the terms of the Base Indenture and Supplemental Indenture No. 11, the Company established and issued a series of its Securities designated as its 4.000% Notes due 2025 (the “Notes”) in the initial aggregate principal amount of $750,000,000, subject to the right of the Company to reopen such series for issuances of additional securities of such series; and

WHEREAS, the Company desires to reopen such series and issue $500,000,000 aggregate principal amount of additional Notes which will constitute a further issuance of, will be fungible with and will be consolidated and form a single series with the Notes, and will have the same CUSIP number and same terms as the Notes.

NOW, THEREFORE, THIS AMENDMENT NO. 1 WITNESSETH:

Pursuant to terms of the Base Indenture and Supplemental Indenture No. 11, the series of Notes established by Supplemental Indenture No. 11 is hereby reopened and there is hereby authorized for issuance, authentication and delivery $500,000,000 aggregate principal amount of additional Notes (the “Additional Notes”) of the same series as the Notes initially issued under Supplemental Indenture No. 11, and in consideration of the premises and the purchase and acceptance of the Additional Notes by the Holders thereof, the Company mutually covenants and agrees with the Trustee, for the equal and proportionate benefit of all Holders of the Notes, that Supplemental Indenture No. 11 is hereby supplemented and amended, to the extent and for the purposes expressed herein, as follows:

ARTICLE 1

AMENDMENTS TO SUPPLEMENTAL INDENTURE NO. 11

Section 1.1 Supplemental Indenture No. 11 is hereby amended and supplemented as follows:

(a) The series of Notes established by Supplemental Indenture No. 11 is hereby reopened for the issuance of Additional Notes in an aggregate principal amount of $500,000,000,

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which shall constitute a further issuance of, will be fungible with and will be consolidated with and form a single series with the Notes, with the same CUSIP number as the Notes, and shall have the same terms as the Notes, except that the Additional Notes will be issued on October 19, 2015, and interest on the Additional Notes shall accrue from May 26, 2015. The form of the Notes, including the Additional Notes, are set forth in Supplemental Indenture No. 11, and such form with respect to the Additional Notes may contain such changes as may be appropriate to reflect the issuance of the Additional Notes and the amendment of Supplemental Indenture No. 11 by this Amendment No. 1.

(b) All references to the Notes in Supplemental Indenture No. 11 and the form of the Notes set forth in Supplemental Indenture No. 11 shall be amended, supplemented and deemed to include the Additional Notes issued hereunder, except that the date of issuance of, and the date from which interest will begin to accrue on, the Additional Notes shall be as set forth in this Amendment No. 1.

(c) The Additional Notes shall be subject to, and be entitled to the benefits of Supplemental Indenture No. 11, as amended hereby, except that the date of issuance of, and the date from which interest will begin to accrue on, the Additional Notes shall be as set forth in this Amendment No. 1.

ARTICLE 2

EFFECTIVENESS

Section 2.1 This Amendment No. 1 shall be effective for all purposes as of the date and time this Amendment No. 1 has been executed and delivered by the Company and the Trustee in accordance with Article Nine of the Base Indenture. As amended and supplemented hereby, the Indenture is hereby confirmed as being in full force and effect.

ARTICLE 3

MISCELLANEOUS

Section 3.1 Unless otherwise provided in this Amendment No. 1, all defined terms used in this Amendment No. 1 shall have the meanings assigned to them in Supplemental Indenture No. 11.

Section 3.2 In the event any provision of this Amendment No. 1 shall be held invalid or unenforceable by any court of competent jurisdiction, such holding shall not invalidate or render unenforceable any other provision hereof or any provision of the Indenture.

Section 3.3 To the extent that any terms of Supplemental Indenture No. 11, as amended by this Amendment No. 1, or the Notes (including the Additional Notes) are inconsistent with the terms of the Indenture, the terms of Supplemental Indenture No. 11, as amended by this Amendment No. 1, or the Notes (including the Additional Notes) shall govern and supersede such inconsistent terms.

Section 3.4 The Trustee shall not be responsible for the validity or sufficiency of this Amendment No. 1, or for the recitals contained herein, all of which shall be taken as statements of the Company.

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Section 3.5 This Amendment No. 1 shall be governed by and construed in accordance with the laws of the State of New York.

Section 3.6 This Amendment No. 1 may be executed in several counterparts, each of which shall be an original and all of which shall constitute but one and the same instrument.

[Signature page follows.]

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IN WITNESS WHEREOF , the Company and the Trustee have caused this Amendment No. 1 to be executed in their respective corporate names as of the date first above written.

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Exhibit 4.4

FORM OF GLOBAL NOTE

[Form of Face of Security]

WELLTOWER INC.

UNLESS THIS CERTIFICATE IS PRESENTED BY AN AUTHORIZED REPRESENTATIVE OF THE DEPOSITORY TRUST COMPANY, A NEW YORK CORPORATION (“DTC”), TO ISSUER OR ITS AGENT FOR REGISTRATION OF TRANSFER, EXCHANGE, OR PAYMENT, AND ANY CERTIFICATE ISSUED IS REGISTERED IN THE NAME OF CEDE & CO. OR IN SUCH OTHER NAME AS IS REQUESTED BY AN AUTHORIZED REPRESENTATIVE OF DTC (AND ANY PAYMENT IS MADE TO CEDE & CO. OR TO SUCH OTHER ENTITY AS IS REQUESTED BY AN AUTHORIZED REPRESENTATIVE OF DTC), ANY TRANSFER, PLEDGE, OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL INASMUCH AS THE REGISTERED OWNER HEREOF, CEDE & CO., HAS AN INTEREST HEREIN.

4.000% Notes due 2025

Welltower Inc., a corporation duly organized and existing under the laws of the State of Delaware and formerly known as Health Care REIT, Inc. (herein called the “Company,” which term includes any successor Person under the Indenture hereinafter referred to), for value received, hereby promises to pay to Cede & Co., or registered assigns, the principal sum of Five Hundred Million Dollars on June 1, 2025, and to pay interest thereon from May 26, 2015, or from the most recent Interest Payment Date to which interest has been paid or duly provided for, semi-annually in arrears on June 1 and December 1 in each year, commencing December 1, 2015 at the rate of 4.000% per annum, until the principal hereof is paid or made available for payment. The interest so payable, and punctually paid or duly provided for, on any Interest Payment Date will, as provided in such Indenture, be paid to the Person in whose name this Security (or one or more Predecessor Securities) is registered at the close of business on the Regular Record Date for such interest, which shall be on the May 15 or November 15 (whether or not a Business Day), as the case may be, next preceding such Interest Payment Date. Any such interest not so punctually paid or duly provided for will forthwith cease to be payable to the Holder on such Regular Record Date and may either be paid to the Person in whose name this Security (or one or more Predecessor Securities) is registered at the close of business on a Special Record Date for the payment of such Defaulted Interest to be fixed by the Trustee, notice whereof shall be given to Holders of Securities of this series not less than 10 days prior to such Special Record Date, or be paid at any time in any other lawful manner not inconsistent with the requirements of any securities exchange on which the Securities of this series may be listed, and upon such notice as may be required by such exchange, all as more fully provided in said Indenture.

Payment of the principal of (and premium, if any) and any such interest on this Security will be made at the office or agency of the Company maintained for that purpose in the City of New York, New York, or elsewhere as provided in the Indenture, in such coin or currency of the United States of America as at the time of payment is legal tender for payment of public and private debts; provided, however, that at the option of the Company payment of interest may be made by electronic wire transfer or by check mailed to the address of the Person entitled thereto as such address shall appear in the Security Register.

Reference is hereby made to the further provisions of this Security set forth on the reverse hereof, which further provisions shall for all purposes have the same effect as if set forth at this place.

No recourse under or upon any obligation, covenant or agreement contained in the Indenture or in this Security, or because of any indebtedness evidenced hereby or thereby, shall be had against any promoter, as such, or against any past, present or future shareholder, officer or director, as such, of the Company or of any successor, either directly or through the Company or any successor, under any rule of law, statute or constitutional provision or by the enforcement of any assessment or by any legal or equitable proceeding or otherwise, all such liability being expressly waived and released by the acceptance of this Security by the Holder thereof and as part of the consideration for the issue of the Securities of this series.

Unless the certificate of authentication hereon has been executed by the Trustee referred to on the reverse hereof by manual signature, this Security shall not be entitled to any benefit under the Indenture or be valid or obligatory for any purpose.

[Signature page follows.]

In Witness Whereof, the Company has caused this instrument to be duly executed under its corporate seal.

CERTIFICATE OF AUTHENTICATION

Dated:                     

This is one of the Securities of the series designated therein referred to in the within-mentioned Indenture.

[Form of Reverse of Security]

1. General . This Security is one of a duly authorized issue of securities of the Company (herein called the “Securities”), issued and to be issued in one or more series under an Indenture, dated as of March 15, 2010 (as amended, supplemented or otherwise modified from time to time, the “Base Indenture”), as supplemented by Supplemental Indenture No. 11, dated as of May 26, 2015 (as amended by Amendment No. 1 thereto, dated as of October 19, 2015, and as further amended, supplemented or otherwise modified from time to time, the “Supplemental Indenture” and the Base Indenture, as supplemented by such Supplemental Indenture, the “Indenture”), between the Company and The Bank of New York Mellon Trust Company, N.A., as Trustee (herein called the “Trustee,” which term includes any successor trustee under the Indenture), and reference is hereby made to the Indenture for a statement of the respective rights, limitations of rights, duties and immunities thereunder of the Company, the Trustee, the holders of Senior Debt and the Holders of the Securities and of the terms upon which the Securities are, and are to be, authenticated and delivered. This Security is one of the series designated on the face hereof.

2. Optional Redemption . The Securities of this series are subject to redemption, at any time or from time to time, as a whole or in part, at the election of the Company. If the Securities are redeemed, the redemption price will equal the sum of (i) the principal amount of the Securities (or portion of such Securities) being redeemed, plus accrued and unpaid interest thereon to but excluding the applicable Redemption Date and (ii) the Make-Whole Amount, if any; provided, however, that if the Securities are redeemed 90 or fewer days prior to the maturity date, the redemption price will equal 100% of the principal amount of the Securities (or portion of such Securities) being redeemed plus accrued and unpaid interest thereon to but excluding the applicable Redemption Date. The Company shall calculate the redemption price.

In the event of redemption of this Security in part only, a new Security or Securities of this series and of like tenor for the unredeemed portion hereof will be issued in the name of the Holder hereof upon the cancellation hereof.

3. Defeasance . The Indenture contains provisions for defeasance at any time of the entire indebtedness of this Security or certain restrictive covenants and Events of Default with respect to this Security, in each case upon compliance with certain conditions set forth in the Indenture.

4. Defaults and Remedies . If an Event of Default with respect to Securities of this series shall occur and be continuing, the principal of the Securities of this series may be declared due and payable in the manner and with the effect provided in the Indenture.

5. Actions of Holders . The Indenture permits, with certain exceptions as therein provided, the amendment thereof and the modification of the rights and obligations of the Company and the rights of the Holders of the Securities of each series to be affected under the Indenture at any time by the Company and the Trustee with the consent of the Holders of a majority in principal amount of the Securities at the time Outstanding of each series to be affected. The Indenture also contains provisions permitting the Holders of specified percentages

in principal amount of the Securities of each series at the time Outstanding, on behalf of the Holders of all Securities of such series, to waive compliance by the Company with certain provisions of the Indenture and certain past defaults under the Indenture and their consequences. Any such consent or waiver by the Holder of this Security shall be conclusive and binding upon such Holder and upon all future Holders of this Security and of any Security issued upon the registration of transfer hereof or in exchange therefor or in lieu hereof, whether or not notation of such consent or waiver is made upon this Security.

As provided in and subject to the provisions of the Indenture, the Holder of this Security shall not have the right to institute any proceeding with respect to the Indenture or for the appointment of a receiver or trustee or for any other remedy thereunder, unless such Holder shall have previously given the Trustee written notice of a continuing Event of Default with respect to the Securities of this series, the Holders of not less than a majority in principal amount of the Securities of this series at the time Outstanding shall have made written request to the Trustee to institute proceedings in respect of such Event of Default as Trustee and offered the Trustee reasonable indemnity, and the Trustee shall not have received from the Holders of a majority in principal amount of Securities of this series at the time Outstanding a direction inconsistent with such request, and shall have failed to institute any such proceeding, for 60 days after receipt of such notice, request and offer of indemnity. The foregoing shall not apply to any suit instituted by the Holder of this Security for the enforcement of any payment of principal hereof or any premium or interest hereon on or after the respective due dates expressed herein.

6. Payments Not Impaired . No reference herein to the Indenture and no provision of this Security or of the Indenture shall alter or impair the obligation of the Company, which is absolute and unconditional, to pay the principal of and any premium and interest on this Security at the times, place and rate, and in the coin or currency, herein prescribed.

7. Denominations, Transfer, Exchange . As provided in the Indenture and subject to certain limitations therein set forth, the transfer of this Security is registrable in the Security Register, upon surrender of this Security for registration of transfer at the office or agency of the Company in any place where the principal of and any premium and interest on this Security are payable, duly endorsed by, or accompanied by a written instrument of transfer in form satisfactory to the Company and the Security Registrar duly executed by, the Holder hereof or his attorney duly authorized in writing, and thereupon one or more new Securities of this series and of like tenor, of authorized denominations and for the same aggregate principal amount, will be issued to the designated transferee or transferees.

The Securities of this series are issuable only in registered form without coupons in minimum denominations of $2,000 and any integral multiple of $1,000. As provided in the Indenture and subject to certain limitations therein set forth, Securities of this series are exchangeable for a like aggregate principal amount of Securities of this series and of like tenor of a different authorized denomination, as requested by the Holder surrendering the same.

No service charge shall be made for any such registration of transfer or exchange, but the Company may require payment of a sum sufficient to cover any tax or other governmental charge payable in connection therewith.

8. Persons Deemed Owners . Prior to due presentment of this Security for registration of transfer, the Company, the Trustee and any agent of the Company or the Trustee may treat the Person in whose name this Security is registered as the owner hereof for all purposes, whether or not this Security be overdue, and neither the Company, the Trustee nor any such agent shall be affected by notice to the contrary.

9. Defined Terms . All terms used in this Security which are defined in the Indenture shall have the meanings assigned to them in the Indenture.

10. Governing Law . The Indenture and the Note shall be deemed to be a contract made under the laws of the State of New York, and for all purposes shall be construed in accordance with the laws of said state.

11. CUSIP Number . Pursuant to a recommendation promulgated by the Committee on Uniform Security Identification Procedures, the Company has caused CUSIP numbers to be printed on the Securities as a convenience to the Holders of the Securities. No representation is made as to the correctness or accuracy of such CUSIP numbers as printed on the Securities, and reliance may be placed only on the other identification numbers printed hereon.

[ASSIGNMENT FORM]

Additional abbreviations may also be used though not in the above list.

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FOR VALUE RECEIVED, the undersigned registered holder hereby sell(s), assign(s) and transfer(s) unto

PLEASE INSERT SOCIAL SECURITY OR OTHER IDENTIFYING NUMBER OF ASSIGNEE