X0306 4 2015-10-28 0 0001446847 IRONWOOD PHARMACEUTICALS INC IRWD 0001478485 Hecht Peter M C/O IRONWOOD PHARMACEUTICALS, INC. 301 BINNEY STREET CAMBRIDGE MA 02142 1 1 0 0 Chief Executive Officer Class B Common Stock 2015-10-28 4 M 0 29102 1.56 A 4170519 D Class B Common Stock 2015-10-28 4 M 0 35000 1.56 A 4205519 D Class B Common Stock 2015-10-28 4 M 0 34013 2.94 A 4239532 D Class A Common Stock 73418 D Class A Common Stock 4850 I The 2000 Trust for Malcom Paul Hecht Class A Common Stock 4850 I The 2000 Trust for Zoe Niovi Hecht Class A Common Stock 4850 I The 2000 Trust for Alexis Mae Hecht Employee Stock Option (Right to Buy) 1.56 2015-10-28 4 M 0 29102 0.00 D 2016-03-14 Class B Common Stock 29102 550790 D Employee Stock Option (Right to Buy) 1.56 2015-10-28 4 M 0 35000 0.00 D 2016-03-13 Class B Common Stock 35000 0 D Employee Stock Option (Right to Buy) 2.94 2015-10-28 4 M 0 34013 0.00 D 2017-01-22 Class B Common Stock 34013 65987 D 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. 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 of Class B Common Stock, respectively. The option vested as to 1.25% of the shares of Class B Common Stock on each monthly anniversary of January 1, 2006 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, 2010. The option vested as to 1.25% of the shares of Class B Common Stock on each monthly anniversary of January 1, 2007 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, 2011. Exhibit 24: Power of Attorney /s/ Mark Gaffney, Attorney-in-Fact 2015-10-29