UNITED STATES
SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE 14A

Proxy Statement Pursuant to Section 14(a) of
the Securities Exchange Act of 1934 (Amendment No.     )

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IRONWOOD PHARMACEUTICALS, INC.
(Name of Registrant as Specified In Its Charter)
(Name of Person(s) Filing Proxy Statement, if other than the Registrant)
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*** Exercise Your Right to Vote *** Important Notice Regarding the Availability of Proxy Materials for the Stockholder Meeting to Be Held on June 1, 2016. IRONWOOD PHARMACEUTICALS, INC. You are receiving this communication because you hold shares in the company named above. This is not a ballot. You cannot use this notice to vote these shares. This communication presents only an overview of the more complete proxy materials that are available to you on the Internet. You may view the proxy materials online at www.proxyvote.com or easily request a paper copy (see reverse side). We encourage you to access and review all of the important information contained in the proxy materials before voting. IRONWOOD PHARMACEUTICALS, INC. 301 BINNEY STREET CAMBRIDGE, MA 02142 proxy materials and voting instructions. E08033-P75959 See the reverse side of this notice to obtain Meeting Information Meeting Type:Annual Meeting For holders as of:April 8, 2016 Date: June 1, 2016Time: 9:00 AM, Eastern Time Location: Ironwood Pharmaceuticals, Inc. 301 Binney Street Cambridge, MA 02142

Before You Vote How to Access the Proxy Materials Have the information that is printed in the box marked by the arrow XXXX XXXX XXXX XXXX (located on the by the arrow XXXX XXXX XXXX XXXX (located on the following page) in the subject line. How To Vote Please Choose One of the Following Voting Methods marked by the arrow XXXX XXXX XXXX XXXX (located on the following page) available and follow the instructions. E08034-P75959 Vote In Person: Many stockholder meetings have attendance requirements including, but not limited to, the possession of an attendance ticket issued by the entity holding the meeting. Please check the meeting materials for any special requirements for meeting attendance and how to obtain directions to the meeting. At the meeting, you will need to request a ballot to vote these shares. Vote By Internet: To vote now by Internet, go to www.proxyvote.com. Have the information that is printed in the box Vote By Mail: You can vote by mail by requesting a paper copy of the materials, which will include a proxy card. Proxy Materials AAvvaaiillaabbllee ttooVVIEIEWWoorrRREECCEEIVIVEE: : 1. NOTICE AND PROXY STATEMENT2. FORM 10-K How to View Online: following page) and visit: www.proxyvote .com. How to Request and Receive a PAPER or E-MAIL Copy: If you want to receive a paper or e-mail copy of these documents, you must request one. There is NO charge for requesting a copy. Please choose one of the following methods to make your request: 1) BY INTERNET:www.proxyvote.com 2) BY TELEPHONE: 1-800-579-1639 3) BY E-MAIL*:sendmaterial@proxyvote.com * If requesting materials by e-mail, please send a blank e-mail with the information that is printed in the box marked Requests, instructions and other inquiries sent to this e-mail address will NOT be forwarded to your investment advisor. Please make the request as instructed above on or before May 18, 2016 to facilitate timely delivery.

The Board of Directors recommends you vote FOR the following: 1. Election of Directors Nominees: 01) 02) 03) 04) Marsha H. Fanucci Terrance G. McGuire Edward P. Owens Christopher T. Walsh The Board of Directors recommends you vote FOR the following proposals: 2. Reapproval of the material terms of the performance goals under the Company's Amended and Restated 2010 Employee, Director and Consultant Equity Incentive Plan. 3. Ratification of the selection of Ernst & Young LLP as the Company's independent registered public accounting firm for 2016. NOTE: In their discretion, the Proxies are authorized to vote upon such other business as may properly come before the meeting or any adjournment or postponement thereof. E08035-P75959 Voting Items

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