X0306 4 2013-06-14 0 0001446847 IRONWOOD PHARMACEUTICALS INC IRWD 0001478521 Higgins Michael J C/O IRONWOOD PHARMACEUTICALS, INC. 301 BINNEY STREET CAMBRIDGE MA 02142 0 1 0 0 Chief Operating Officer Class B Common Stock 2013-06-14 4 M 0 144100 0.60 A 385766 D Class B Common Stock 2013-06-14 4 S 0 144100 11.74 D 241666 D Class B Common Stock 2013-06-17 4 M 0 30900 0.60 A 272566 D Class B Common Stock 2013-06-17 4 S 0 5900 11.84 D 266666 D Class B Common Stock 2013-06-17 4 M 0 33334 0.60 A 300000 D Class A Common Stock 2013-06-17 4 M 0 50000 0.60 A 50000 D Employee Stock Option (Right to Buy) 0.60 2013-06-14 4 M 0 144100 0.00 D 2013-07-15 Class B Common Stock 144100 80900 D Employee Stock Option (Right to Buy) 0.60 2013-06-17 4 M 0 80900 0.00 D 2013-07-15 Class B Common Stock 80900 0 D Employee Stock Option (Right to Buy) 0.60 2013-06-17 4 M 0 33334 0.00 D 2013-07-15 Class B Common Stock 33334 0 D Sales of a total of 150,000 shares of Class A Common Stock, as reported on this form, were executed to provide funds to cover the exercise price and associated federal and state taxes required to exercise 258,334 non-qualified stock options granted on July 15, 2003, which were scheduled to expire on July 15, 2013. This sale was effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person. 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. The price reported is a weighted average price. These shares were sold in multiple transactions at prices ranging from $11.55 to $11.96, 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. The price reported is a weighted average price. These shares were sold in multiple transactions at prices ranging from $11.78 to $11.91, 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. The reporting person immediately converted 50,000 shares of Class B Common Stock acquired upon exercise of the stock option into 50,000 shares of Class A Common Stock. The Class B Common Stock is convertible into Class A Common Stock at any time on a one-for-one basis, in accordance with the issuer's certificate of incorporation. The option vested as to 25% of the shares of Class B Common Stock on the first anniversary of May 5, 2003 and 1/48th of the shares of Class B Common Stock vested each month thereafter for the next 36 months. The option was fully vested as of May 5, 2007. The option vested in installments upon the issuer's achievement of certain market capitalization, financing and clinical milestones. The milestones were met, and the option was fully vested as of December 31, 2006. /s/ Halley E. Gilbert Attorney-in-Fact 2013-06-18