Ownership Submission
FORM 4
Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).
UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940
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(Print or Type Responses)
1. Name and Address of Reporting Person *
GADICKE ANSBERT
  2. Issuer Name and Ticker or Trading Symbol
Radius Health, Inc. [NONE]
5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
__X__ Director __X__ 10% Owner
_____ Officer (give title below) _____ Other (specify below)
(Last)
(First)
(Middle)
C/O MPM ASSET MANAGEMENT, 200 CLARENDON ST., 54TH FLOOR
3. Date of Earliest Transaction (Month/Day/Year)
04/23/2013
(Street)

BOSTON, MA 02116
4. If Amendment, Date Original Filed(Month/Day/Year)
6. Individual or Joint/Group Filing(Check Applicable Line)
_X_ Form filed by One Reporting Person
___ Form filed by More than One Reporting Person
(City)
(State)
(Zip)
Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1.Title of Security
(Instr. 3)
2. Transaction Date (Month/Day/Year) 2A. Deemed Execution Date, if any (Month/Day/Year) 3. Transaction Code
(Instr. 8)
4. Securities Acquired (A) or Disposed of (D)
(Instr. 3, 4 and 5)
5. Amount of Securities Beneficially Owned Following Reported Transaction(s)
(Instr. 3 and 4)
6. Ownership Form: Direct (D) or Indirect (I)
(Instr. 4)
7. Nature of Indirect Beneficial Ownership
(Instr. 4)
Code V Amount (A) or (D) Price

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
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Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security
(Instr. 3)
2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (Month/Day/Year) 3A. Deemed Execution Date, if any (Month/Day/Year) 4. Transaction Code
(Instr. 8)
5. Number of Derivative Securities Acquired (A) or Disposed of (D)
(Instr. 3, 4, and 5)
6. Date Exercisable and Expiration Date
(Month/Day/Year)
7. Title and Amount of Underlying Securities
(Instr. 3 and 4)
8. Price of Derivative Security
(Instr. 5)
9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s)
(Instr. 4)
10. Ownership Form of Derivative Security: Direct (D) or Indirect (I)
(Instr. 4)
11. Nature of Indirect Beneficial Ownership
(Instr. 4)
Code V (A) (D) Date Exercisable Expiration Date Title Amount or Number of Shares
Series B Convertible Preferred Stock (1) 04/23/2013   A   5,103   04/23/2013   (1) Common Stock 51,030 $ 61.42 (8) 5,103 I By Fund (2)
Common Stock Warrant $ 6.142 04/23/2013   A   12,758   04/23/2013 04/23/2018 Common Stock 12,758 (8) 12,758 I By Fund (2)
Series B Convertible Preferred Stock (1) 04/23/2013   A   75,899   04/23/2013   (1) Common Stock 758,990 $ 61.42 (8) 75,899 I By Fund (3)
Common Stock Warrant $ 6.142 04/23/2013   A   189,748   04/23/2013 04/23/2018 Common Stock 189,748 (8) 189,748 I By Fund (3)
Series B Convertible Preferred Stock (1) 04/23/2013   A   6,414   04/23/2013   (1) Common Stock 64,140 $ 61.42 (8) 6,414 I By Fund (4)
Common Stock Warrant $ 6.142 04/23/2013   A   16,035   04/23/2013 04/23/2018 Common Stock 16,035 (8) 16,035 I By Fund (4)
Series B Convertible Preferred Stock (1) 04/23/2013   A   2,291   04/23/2013   (1) Common Stock 22,910 $ 61.42 (8) 2,291 I By Fund (5)
Common Stock Warrant $ 6.142 04/23/2013   A   5,728   04/23/2013 04/23/2018 Common Stock 5,728 (8) 5,728 I By Fund (5)
Series B Convertible Preferred Stock (1) 04/23/2013   A   1,468   04/23/2013   (1) Common Stock 14,680 $ 61.42 (8) 1,468 I By Fund (6)
Common Stock Warrant $ 6.142 04/23/2013   A   3,670   04/23/2013 04/23/2018 Common Stock 3,670 (8) 3,670 I By Fund (6)
Series B Convertible Preferred Stock (1) 04/23/2013   A   71,638   04/23/2013   (1) Common Stock 716,380 $ 61.42 (8) 71,638 I By Fund (7)
Common Stock Warrant $ 6.142 04/23/2013   A   179,095   04/23/2013 04/23/2018 Common Stock 179,095 (8) 179,095 I By Fund (7)

Reporting Owners

Reporting Owner Name / Address Relationships
 Director  10% Owner  Officer  Other
GADICKE ANSBERT
C/O MPM ASSET MANAGEMENT
200 CLARENDON ST., 54TH FLOOR
BOSTON, MA 02116
  X   X    

Signatures

 /s/ Ansbert Gadicke   04/24/2013
**Signature of Reporting Person Date

Explanation of Responses:

* If the form is filed by more than one reporting person, see Instruction 4(b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
(1) Each share of the Series B Convertible Preferred Stock has no expiration date and is convertible at any time, in whole or in part, at the election of the holder at a conversion rate of 10 shares of Common Stock for every 1 share of Series B Convertible Preferred Stock.
(2) The reported securities are owned directly by MPM BioVentures III, L.P. ("BV III"). MPM BioVentures III GP, L.P. ("MPM III GP") and MPM BioVentures III LLC ("MPM III LLC") are the direct and indirect general partners of BV III. The reporting person is a member of MPM III LLC. The reporting person disclaims beneficial ownership of the securities reported herein except to the extent of his pecuniary interest therein.
(3) The reported securities are owned directly by MPM BioVentures III-QP, L.P. ("BV III QP"). MPM III GP and MPM III LLC are the direct and indirect general partners of BV III QP. The reporting person is a member of MPM III LLC. The reporting person disclaims beneficial ownership of the securities reported herein except to the extent of his pecuniary interest therein.
(4) The reported securities are owned directly by MPM BioVentures III GmbH & Co. Beteiligungs KG ("BV KG"). MPM III GP and MPM III LLC are the direct and indirect general partners of BV KG. The reporting person is a member of MPM III LLC. The reporting person disclaims beneficial ownership of the securities reported herein except to the extent of his pecuniary interest therein.
(5) The reported securities are owned directly by MPM BioVentures III Parallel Fund, L.P. ("BV Parallel"). MPM III GP and MPM III LLC are the direct and indirect general partners of BV Parallel. The reporting person is a member of MPM III LLC. The reporting person disclaims beneficial ownership of the securities reported herein except to the extent of his pecuniary interest therein.
(6) The reported securities are owned directly by MPM Asset Management Investors 2003 BVIII LLC ("AM 2003"). The reporting person is a member of AM 2003. The reporting person disclaims beneficial ownership of the securities reported herein except to the extent of his pecuniary interest therein.
(7) The reported securities are owned directly by MPM Bio IV NVS Strategic Fund, L.P. ("MPM NVS"). MPM BioVentures IV GP LLC and MPM BioVentures IV LLC ("BV IV LLC") are the direct and indirect general partners of MPM NVS. The reporting person is a member of BV IV LLC. The reporting person disclaims beneficial ownership of the securities reported herein except to the extent of his pecuniary interest therein.
(8) Payment of an aggregate purchase price equal to the product of (i) $61.42 multiplied by (ii) the total number of reported shares of Series B Convertible Preferred Stock, entitled the purchaser to receive the reported shares of Series B Convertible Preferred Stock as well as the reported warrant exercisable for shares of Common Stock.

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