Ownership Submission
FORM 4
Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).
UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940
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(Print or Type Responses)
1. Name and Address of Reporting Person *
Hecht Peter M
  2. Issuer Name and Ticker or Trading Symbol
IRONWOOD PHARMACEUTICALS INC [IRWD]
5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
__X__ Director _____ 10% Owner
__X__ Officer (give title below) _____ Other (specify below)
Chief Executive Officer
(Last)
(First)
(Middle)
C/O IRONWOOD PHARMACEUTICALS, INC., 301 BINNEY STREET
3. Date of Earliest Transaction (Month/Day/Year)
02/27/2015
(Street)

CAMBRIDGE, MA 02142
4. If Amendment, Date Original Filed(Month/Day/Year)
6. Individual or Joint/Group Filing(Check Applicable Line)
_X_ Form filed by One Reporting Person
___ Form filed by More than One Reporting Person
(City)
(State)
(Zip)
Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1.Title of Security
(Instr. 3)
2. Transaction Date (Month/Day/Year) 2A. Deemed Execution Date, if any (Month/Day/Year) 3. Transaction Code
(Instr. 8)
4. Securities Acquired (A) or Disposed of (D)
(Instr. 3, 4 and 5)
5. Amount of Securities Beneficially Owned Following Reported Transaction(s)
(Instr. 3 and 4)
6. Ownership Form: Direct (D) or Indirect (I)
(Instr. 4)
7. Nature of Indirect Beneficial Ownership
(Instr. 4)
Code V Amount (A) or (D) Price
Class B Common Stock 02/27/2015   M   210,000 A $ 0.6 4,184,751 D  
Class B Common Stock 02/27/2015   S(1)   20,400 D $ 16.06 (2) 4,164,351 D  
Class B Common Stock 02/27/2015   S(1)   22,934 D $ 15.34 (3) 4,141,417 D  
Class B Common Stock 03/02/2015   M   13,908 A $ 1.56 4,155,325 D  
Class B Common Stock 03/02/2015   S(1)   13,908 D $ 16 (4) 4,141,417 D  
Class B Common Stock 03/03/2015   M   6,200 A $ 1.56 4,147,617 D  
Class B Common Stock 03/03/2015   S(1)   6,200 D $ 15.71 (5) 4,141,417 D  
Class A Common Stock               73,418 D  
Class A Common Stock               4,850 I The 2000 Trust for Malcolm Paul Hecht (6)
Class A Common Stock               4,850 I The 2000 Trust for Zoe Niovi Hecht (6)
Class A Common Stock               4,850 I The 2000 Trust for Alexis Mae Hecht (6)

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
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Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security
(Instr. 3)
2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (Month/Day/Year) 3A. Deemed Execution Date, if any (Month/Day/Year) 4. Transaction Code
(Instr. 8)
5. Number of Derivative Securities Acquired (A) or Disposed of (D)
(Instr. 3, 4, and 5)
6. Date Exercisable and Expiration Date
(Month/Day/Year)
7. Title and Amount of Underlying Securities
(Instr. 3 and 4)
8. Price of Derivative Security
(Instr. 5)
9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s)
(Instr. 4)
10. Ownership Form of Derivative Security: Direct (D) or Indirect (I)
(Instr. 4)
11. Nature of Indirect Beneficial Ownership
(Instr. 4)
Code V (A) (D) Date Exercisable Expiration Date Title Amount or Number of Shares
Employee Stock Option (Right to Buy) $ 0.6 02/27/2015   M     90,000   (7) 03/01/2015 Class B Common Stock 90,000 $ 0 0 D  
Employee Stock Option (Right to Buy) $ 0.6 02/27/2015   M     60,000   (8) 03/01/2015 Class B Common Stock 60,000 $ 0 0 D  
Employee Stock Option (Right to Buy) $ 0.6 02/27/2015   M     60,000   (9) 03/01/2015 Class B Common Stock 60,000 $ 0 0 D  
Employee Stock Option (Right to Buy) $ 1.56 03/02/2015   M     13,908   (10) 03/14/2016 Class B Common Stock 13,908 $ 0 786,092 D  
Employee Stock Option (Right to Buy) $ 1.56 03/03/2015   M     6,200   (10) 03/14/2016 Class B Common Stock 6,200 $ 0 779,892 D  

Reporting Owners

Reporting Owner Name / Address Relationships
 Director  10% Owner  Officer  Other
Hecht Peter M
C/O IRONWOOD PHARMACEUTICALS, INC.
301 BINNEY STREET
CAMBRIDGE, MA 02142
  X     Chief Executive Officer  

Signatures

 /s/ Halley E. Gilbert Attorney-in-Fact   03/03/2015
**Signature of Reporting Person Date

Explanation of Responses:

* If the form is filed by more than one reporting person, see Instruction 4(b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
(1) This sale was effected to cover the tax liabilities arising out of the exercises of stock options of the issuer reported on this form, as well as prior exercises in which the reporting person paid the exercise price and held the underlying shares at the time of exercise. In order to effect the sale, these shares of Class B Common Stock were converted into shares of Class A Common Stock in accordance with the issuer's certificate of incorporation.
(2) The price reported is a weighted average price. These shares were sold in multiple transactions at prices ranging from $16.01 to $16.13, inclusive. The reporting person undertakes to provide to the issuer, any security holder of the issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote.
(3) The price reported is a weighted average price. These shares were sold in multiple transactions at prices ranging from $15.32 to $15.38, inclusive. The reporting person undertakes to provide to the issuer, any security holder of the issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote.
(4) The price reported is a weighted average price. These shares were sold in multiple transactions at prices ranging from $16.00 to $16.01, inclusive. The reporting person undertakes to provide to the issuer, any security holder of the issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote.
(5) The price reported is a weighted average price. These shares were sold in multiple transactions at prices ranging from $15.70 to $15.77, inclusive. The reporting person undertakes to provide to the issuer, any security holder of the issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in this footnote.
(6) These shares are held in the referenced trust for the benefit of the reporting person's child. The reporting person's spouse is the trustee of this trust. The reporting person disclaims beneficial ownership of these securities, and the filing of this report is not an admission that the reporting person is the beneficial owner of these securities for purposes of Section 16 or any other purpose.
(7) The option vested as to 1.25% of the shares of Class B Common Stock on each monthly anniversary of January 1, 2005 for the first 36 months, and as to 4.5833% of the shares of Class B Common Stock each monthly anniversary thereafter. The option was fully vested as of January 1, 2009.
(8) The option vested in equal monthly installments on each monthly anniversary of January 1, 2005 for twelve months. The option was fully vested as of January 1, 2006.
(9) The option vested upon the issuer's completion of a substantial transaction, as determined by the Compensation and HR Committee of the issuer's Board of Directors. The milestone was met, so the option was fully vested as of January 1, 2009.
(10) The option vests upon the earlier of (i) the issuer's achievement of certain regulatory, commercial and market capitalization milestones and (ii) January 1, 2016. Upon achievement of a regulatory milestone on October 24, 2011 and a commercial milestone on December 21, 2012, the option vested as to 400,000 and 300,000 shares, respectively.

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