X0306 4 2018-02-21 0 0001446847 IRONWOOD PHARMACEUTICALS INC IRWD 0001601360 Gilbert Halley E C/O IRONWOOD PHARMACEUTICALS, INC. 301 BINNEY STREET CAMBRIDGE MA 02142 0 1 0 0 Chief Legal Officer Class A Common Stock 2018-02-21 4 S 0 2343 14.66 D 99602 D Class A Common Stock 2018-02-21 4 S 0 2411 14.66 D 97191 D Class A Common Stock 2018-02-21 4 S 0 2987 14.66 D 94204 D Class A Common Stock 2018-02-21 4 A 0 35000 0.00 A 129204 D Employee Stock Option(Right to Buy) 14.55 2018-02-21 4 A 0 70000 0.00 A 2028-02-21 Class A Common Stock 70000 70000 D This sale was effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person. This sale was made to cover tax withholding obligations in connection with the vesting and settlement of approximately 25% of the reporting person's restricted stock units granted on March 16, 2015. The price reported is a weighted average price. These shares were sold in multiple transactions at prices ranging from $14.48 to $14.92, 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 acquired a total of 1,138 shares of Class A Common Stock under the issuer's employee stock purchase plan in the following transactions: 791 shares acquired on June 30, 2017 and 347 shares acquired on December 31, 2017. This sale was effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person. This sale was made to cover tax withholding obligations in connection with the vesting and settlement of approximately 25% of the reporting person's restricted stock units granted on March 1, 2016. This sale was effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person. This sale was made to cover tax withholding obligations in connection with the vesting and settlement of approximately 25% of the reporting person's restricted stock units granted on February 27, 2017. The restricted stock unit award, granted as an annual performance award, vests as to 25% of the shares of Class A Common Stock on each approximate anniversary of the grant thereof. The option, granted as an annual performance award, vests as to 2.08333% of the shares of Class A Common Stock on each monthly anniversary of January 1, 2018. /s/ Conor Kilroy, Attorney-in-Fact 2018-02-22