SCHEDULE 13G

Amendment No. 3
AMAG PHARMACEUTICALS INC
Common Stock
Cusip #00163U106

Cusip #00163U106
Item 1: 	   	Reporting Person - FMR LLC
Item 4: 	   	Delaware
Item 5: 	   	0
Item 6: 	   	0
Item 7: 	   	1,482,681
Item 8: 	   	0
Item 9: 	   	1,482,681
Item 11: 	  	6.837%
Item 12: 	  	HC

Cusip #00163U106
Item 1: 	   	Reporting Person - Edward C. Johnson 3d
Item 4: 	   	United States of America
Item 5: 	   	0
Item 6: 	   	0
Item 7: 	   	1,482,681
Item 8: 	   	0
Item 9: 	   	1,482,681
Item 11: 	  	6.837%
Item 12: 	  	IN

SCHEDULE 13G - TO BE INCLUDED IN STATEMENTS
FILED PURSUANT TO RULE 13d-1(b) or 13d-2(b)

Item 1(a). 	    	Name of Issuer:

  	  	          	AMAG PHARMACEUTICALS INC

Item 1(b). 	    	Name of Issuer's Principal Executive Offices:

  	  	          	100 Hayden Avenue
  	  	          	Lexington, MA 02140
  	  	          	USA

Item 2(a). 	     	 Name of Person Filing:

  	   	               	 FMR LLC

Item 2(b). 	     	 Address or Principal Business Office or, if None,
Residence:

  	   	               	 245 Summer Street,Boston,Massachusetts 02210

Item 2(c). 	     	 Citizenship:

  	   	               	 Not applicable

Item 2(d). 	     	 Title of Class of Securities:

  	   	               	 Common Stock

Item 2(e). 	     	 CUSIP Number:

  	   	               	 00163U106

Item 3. 	    	This statement is filed pursuant to Rule 13d-1(b) or 13d-2(b)
and the person filing,
FMR LLC, is a parent holding company in accordance with Section 240.13d-
1(b)(ii)(G).   (Note:  See Item 7).

Item 4. 	    	Ownership

  	  	     	(a)    Amount Beneficially Owned: 	1,482,681

  	  	     	(b)    Percent of Class: 	6.837%

  	  	     	(c)    Number of shares as to which such person has:

  	  	     	       (i)    sole power to vote or to direct the vote: 	0

  	  	     	       (ii)    shared power to vote or to direct the vote: 	0

  	  	     	       (iii)    sole power to dispose or to direct the
disposition of: 	1,482,681

  	  	     	       (iv)    shared power to dispose or to direct the
disposition of: 	0

Item 5. 	    	Ownership of Five Percent or Less of a Class.

  	    	     	Not applicable.

Item 6. 	    	Ownership of More than Five Percent on Behalf of Another
Person.

  	    	     	Various persons have the right to receive or the power to
direct the receipt of dividends from, or the proceeds from the sale of, the
Common Stock of AMAG PHARMACEUTICALS INC. No one person's interest in the
Common Stock of AMAG PHARMACEUTICALS INC is more than five percent of the
total outstanding Common Stock.

Item 7. 	    	Identification and Classification of the Subsidiary Which
Acquired the Security Being Reported on By the Parent Holding Company.

  	    	     	See attached Exhibit A.

Item 8. 	    	Identification and Classification of Members of the Group.

  	    	     	Not applicable. See attached Exhibit A.

Item 9. 	    	Notice of Dissolution of Group.

  	    	  	Not applicable.

Item 10. 	    	Certification.



By signing below I certify that, to the best of my knowledge and belief,
the securities referred to above were acquired in the ordinary course of
business and were not acquired for the purpose of and do not have the
effect of changing or influencing the control of the issuer of such
securities and were not acquired in connection with or as a participant in
any transaction having such purpose or effect.


Signature



After reasonable inquiry and to the best of my knowledge and belief, I
certify that the information set forth in this statement is true, complete
and correct.

  	November 8, 2013
  	Date

  	/s/ Scott C. Goebel
  	Signature

  	Scott C. Goebel
  	 Duly authorized under Power of Attorney effective as of June 1, 2008,
by and on behalf of FMR LLC and its direct and indirect subsidiaries
SCHEDULE 13G - TO BE INCLUDED IN STATEMENTS
FILED PURSUANT TO RULE 13d-1(b) or 13d-2(b)


                Pursuant to the instructions in Item 7 of Schedule 13G,
Fidelity Management & Research Company ("Fidelity"), 245 Summer Street,
Boston, Massachusetts 02210, a wholly-owned subsidiary of FMR LLC and an
investment adviser registered under Section 203 of the Investment Advisers
Act of 1940, is the beneficial owner of 517,061 shares or 2.387% of the
Common Stock outstanding of AMAG PHARMACEUTICALS INC ("the Company") as a
result of acting as investment adviser to various investment companies
registered under Section 8 of the investment Company Act of 1940.



                Edward C. Johnson 3d and FMR LLC, through its control of
Fidelity, and the funds each has sole power to dispose of the 517,061
shares owned by the Funds.

		Fidelity SelectCo, LLC ("SelectCo"), 1225 17th Street,
Suite 1100, Denver, Colorado 80202, a wholly-owned subsidiary of FMR LLC
and an investment adviser registered under Section 203 of the Investment
Advisers Act of 1940, is the beneficial owner of 965,620 shares or
4.450% of the outstanding Common Stock outstanding of AMAG
PHARMACEUTICALS INC ("the Company") as a result of acting as investment
adviser  to various investment companies registered under Section 8 of
the Investment Company Act of 1940 (the "SelectCo Funds").



                Edward C. Johnson 3d and FMR LLC, through its control
of SelectCo, and the SelectCo Funds each has sole power to dispose of
the 965,620 shares owned by the SelectCo Funds.



                Members of the family of Edward C. Johnson 3d, Chairman of
FMR LLC, are the predominant owners, directly or through trusts, of Series
B voting common shares of FMR LLC, representing 49% of the voting power of
FMR LLC. The Johnson family group and all other Series B shareholders have
entered into a shareholders' voting agreement under which all Series B
voting common shares will be voted in accordance with the majority vote of
Series B voting common shares. Accordingly, through their ownership of
voting common shares and the execution of the shareholders' voting
agreement, members of the Johnson family may be deemed, under the
Investment Company Act of 1940, to form a controlling group with respect to
FMR LLC.



                Neither FMR LLC nor Edward C. Johnson 3d, Chairman of FMR
LLC, has the sole power to vote or direct the voting of the shares owned
directly by the Fidelity Funds, which power resides with the Funds' Boards
of Trustees. Fidelity carries out the voting of the shares under written
guidelines established by the Funds' Boards of Trustees.


SCHEDULE 13G - TO BE INCLUDED IN STATEMENTS
FILED PURSUANT TO RULE 13d-1(b) or 13d-2(b)
RULE 13d-1(f)(1) AGREEMENT


                The undersigned persons, on November 8, 2013, agree and
consent to the joint filing on their behalf of this Schedule 13G in
connection with their beneficial ownership of the Common Stock of AMAG
PHARMACEUTICALS INC at October 31, 2013.


  	FMR LLC

  	By /s/ Scott C. Goebel
  	Scott C. Goebel
  	Duly authorized under Power of Attorney effective as of June 1, 2008, by
and on behalf of FMR LLC and its direct and indirect subsidiaries

  	Edward C. Johnson 3d

  	By /s/ Scott C. Goebel
  	Scott C. Goebel
  	Duly authorized under Power of Attorney effective as of June 1, 2008, by
and on behalf of Edward C. Johnson 3d

  	Fidelity Management & Research Company

  	By /s/ Scott C. Goebel
  	Scott C. Goebel
  	Senior V.P. and General Counsel