Amag Pharmaceuticals (AMAG) SC 13D AMAG PHARMACEUTICALS / Shkreli Martin ownership change

Exhibit 1

JOINT FILING AGREEMENT

The undersigned hereby agree that this Statement on Schedule 13D with respect to the shares of common stock of AMAG Pharmaceuticals, Inc. dated the date hereof, is, and any amendments thereto signed by the undersigned shall be, filed on behalf of each of the undersigned pursuant to and in accordance with the provisions of Rule 13d-1(k) under the Securities Exchange Act of 1934, as amended.

Dated: October 7, 2011

BLOOMFIELD PARTNERS LP

/s/ Martin Shkreli                                                      

Name:  Martin Shkreli

Title:    Authorized Person

POMPEII MANAGEMENT, LLC

/s/ Martin Shkreli                                                      

Name:  Martin Shkreli

Title:    Authorized Person

MSMB CAPITAL MANAGEMENT, LLC

/s/ Martin Shkreli                                                      

Name:  Martin Shkreli

Title:    Managing Member

MSMB HEALTHCARE LP

By MSMB Healthcare Investors LLC, its general partner

/s/ Martin Shkreli                                                      

Name:  Martin Shkreli

Title:    Managing Member

MSMB HEALTHCARE INVESTORS LLC

/s/ Martin Shkreli                                                      

Name:  Martin Shkreli

Title:    Managing Member

MSMB HEALTHCARE MANAGEMENT LLC

/s/ Martin Shkreli                                                      

Name:  Martin Shkreli

Title:    Managing Member

/s/ Martin Shkreli                                                      

Martin Shkreli