The 28-year-old actress teamed up with the women's rights group earlier this month as she went on a tour promoting her new book, 'Not That Kind of Girl', reported Contactmusic.
The limited edition pink shirt that was sold during the tour is printed with the message 'Lena loves Planned Parenthood', and is available for purchase online, with all proceeds going towards the nonpartisan advocacy and political arm of the organisation.
Dunham has called on some of her fellow female celebrities to share their support of sexual and reproductive health services to women across America.