UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549


                                  SCHEDULE 13G

                    Under the Securities Exchange Act of 1934
                                (Amendment No.)*

                         UNITED THERAPEUTICS CORPORATION
--------------------------------------------------------------------------------
                                (Name of Issuer)


                     Common Stock, Par Value $.01 Per Share
--------------------------------------------------------------------------------
                         (Title of Class of Securities)

                                    91307C102
                                    ---------
                                 (CUSIP Number)

                                  July 18, 2007
                                  -------------
                      (Date of Event which Requires Filing
                               of this Statement)



Check the appropriate box to designate the rule pursuant to which this Schedule
is filed:

             [ ]      Rule 13d-1(b)
             [X]      Rule 13d-1(c)
             [ ]      Rule 13d-1(d)



*The remainder of this cover page shall be filled out for a reporting person's
initial filing on this form with respect to the subject class of securities, and
for any subsequent amendment containing information which would alter the
disclosures provided in a prior cover page.

The information required on the remainder of this cover page shall not be deemed
to be "filed" for the purpose of Section 18 of the Securities Exchange Act of
1934 ("Act") or otherwise subject to the liabilities of that section of the Act
but shall be subject to all other provisions of the Act (however, see the
Notes).


                                  Page 1 of 10





-------------------                                           ------------------
CUSIP No. 91307C102                   13G                     Page 2 of 10 Pages
-------------------                                           ------------------

---------- ---------------------------------------------------------------------
        1  NAME OF REPORTING PERSON
           I.R.S. IDENTIFICATION NO. OF ABOVE PERSON

           S.A.C. Capital Advisors, LLC
---------- ---------------------------------------------------------------------
        2  CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
                                                                      (a) [ ]
                                                                      (b) [X]
---------- ---------------------------------------------------------------------
        3  SEC USE ONLY

---------- ---------------------------------------------------------------------
        4  CITIZENSHIP OR PLACE OF ORGANIZATION

           Delaware
--------------------- ----- ----------------------------------------------------
                         5  SOLE VOTING POWER

                            0
NUMBER OF             ----- ----------------------------------------------------
SHARES                   6  SHARED VOTING POWER
BENEFICIALLY
OWNED                       789,354 (1) (see Item 4)
BY                    ----- ----------------------------------------------------
EACH                     7  SOLE DISPOSITIVE POWER
REPORTING
PERSON                      0
WITH                  ----- ----------------------------------------------------
                         8  SHARED DISPOSITIVE POWER

                            789,354 (1) (see Item 4)
---------- ---------------------------------------------------------------------
        9  AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

           789,354 (1) (see Item 4)
---------- ---------------------------------------------------------------------
       10  CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES

           [ ]
---------- ---------------------------------------------------------------------
       11  PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)

           3.8% (1) (see Item 4)
---------- ---------------------------------------------------------------------
       12  TYPE OF REPORTING PERSON*

           00
---------- ---------------------------------------------------------------------
                       *SEE INSTRUCTION BEFORE FILLING OUT


                                  Page 2 of 10





-------------------                                           ------------------
CUSIP No. 91307C102                   13G                     Page 3 of 10 Pages
-------------------                                           ------------------

---------- ---------------------------------------------------------------------
        1  NAME OF REPORTING PERSON
           I.R.S. IDENTIFICATION NO. OF ABOVE PERSON

           S.A.C. Capital Management, LLC
---------- ---------------------------------------------------------------------
        2  CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
                                                                      (a) [ ]
                                                                      (b) [X]
---------- ---------------------------------------------------------------------
        3  SEC USE ONLY

---------- ---------------------------------------------------------------------
        4  CITIZENSHIP OR PLACE OF ORGANIZATION

           Delaware
--------------------- ----- ----------------------------------------------------
                         5  SOLE VOTING POWER

                            0
NUMBER OF             ----- ----------------------------------------------------
SHARES                   6  SHARED VOTING POWER
BENEFICIALLY
OWNED                       789,354 (1) (see Item 4)
BY                    ----- ----------------------------------------------------
EACH                     7  SOLE DISPOSITIVE POWER
REPORTING
PERSON                      0
WITH                  ----- ----------------------------------------------------
                         8  SHARED DISPOSITIVE POWER

                            789,354 (1) (see Item 4)
---------- ---------------------------------------------------------------------
        9  AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

           789,354 (1) (see Item 4)
---------- ---------------------------------------------------------------------
       10  CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES

           [ ]
---------- ---------------------------------------------------------------------
       11  PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)

           3.8% (1) (see Item 4)
---------- ---------------------------------------------------------------------
       12  TYPE OF REPORTING PERSON*

           00
---------- ---------------------------------------------------------------------
                       *SEE INSTRUCTION BEFORE FILLING OUT


                                  Page 3 of 10





-------------------                                           ------------------
CUSIP No. 91307C102                   13G                     Page 4 of 10 Pages
-------------------                                           ------------------

---------- ---------------------------------------------------------------------
        1  NAME OF REPORTING PERSON
           I.R.S. IDENTIFICATION NO. OF ABOVE PERSON

           CR Intrinsic Investors, LLC
---------- ---------------------------------------------------------------------
        2  CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
                                                                      (a) [ ]
                                                                      (b) [X]
---------- ---------------------------------------------------------------------
        3  SEC USE ONLY

---------- ---------------------------------------------------------------------
        4  CITIZENSHIP OR PLACE OF ORGANIZATION

           Delaware
--------------------- ----- ----------------------------------------------------
                         5  SOLE VOTING POWER

                            0
NUMBER OF             ----- ----------------------------------------------------
SHARES                   6  SHARED VOTING POWER
BENEFICIALLY
OWNED                       452,000 (2) (see Item 4)
BY                    ----- ----------------------------------------------------
EACH                     7  SOLE DISPOSITIVE POWER
REPORTING
PERSON                      0
WITH                  ----- ----------------------------------------------------
                         8  SHARED DISPOSITIVE POWER

                            452,000 (2) (see Item 4)
---------- ---------------------------------------------------------------------
        9  AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

           452,000 (2) (see Item 4)
---------- ---------------------------------------------------------------------
       10  CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES

           [ ]
---------- ---------------------------------------------------------------------
       11  PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)

           2.2% (2) (see Item 4)
---------- ---------------------------------------------------------------------
       12  TYPE OF REPORTING PERSON*

           00
---------- ---------------------------------------------------------------------
                       *SEE INSTRUCTION BEFORE FILLING OUT


                                  Page 4 of 10





-------------------                                           ------------------
CUSIP No. 91307C102                   13G                     Page 5 of 10 Pages
-------------------                                           ------------------

---------- ---------------------------------------------------------------------
        1  NAME OF REPORTING PERSON
           I.R.S. IDENTIFICATION NO. OF ABOVE PERSON

           Steven A. Cohen
---------- ---------------------------------------------------------------------
        2  CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
                                                                      (a) [ ]
                                                                      (b) [X]
---------- ---------------------------------------------------------------------
        3  SEC USE ONLY

---------- ---------------------------------------------------------------------
        4  CITIZENSHIP OR PLACE OF ORGANIZATION

           United States
--------------------- ----- ----------------------------------------------------
                         5  SOLE VOTING POWER

                            0
NUMBER OF             ----- ----------------------------------------------------
SHARES                   6  SHARED VOTING POWER
BENEFICIALLY
OWNED                       1,241,354 (3) (see Item 4)
BY                    ----- ----------------------------------------------------
EACH                     7  SOLE DISPOSITIVE POWER
REPORTING
PERSON                      0
WITH                  ----- ----------------------------------------------------
                         8  SHARED DISPOSITIVE POWER

                            1,241,354 (3) (see Item 4)
---------- ---------------------------------------------------------------------
        9  AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

           1,241,354 (3) (see Item 4)
---------- ---------------------------------------------------------------------
       10  CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES

           [ ]
---------- ---------------------------------------------------------------------
       11  PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)

           6.0% (3) (see Item 4)
---------- ---------------------------------------------------------------------
       12  TYPE OF REPORTING PERSON*

           IN
---------- ---------------------------------------------------------------------
                       *SEE INSTRUCTION BEFORE FILLING OUT


                                  Page 5 of 10





Item 1(a)           Name of Issuer:
                    --------------

                    United Therapeutics Corporation

Item 1(b)           Address of Issuer's Principal Executive Offices:
                    -----------------------------------------------

                    1110 Spring Street, Silver Spring, MD 20910

Items 2(a)          Name of Person Filing:
                    ---------------------

                    This statement is filed by: (i) S.A.C. Capital Advisors, LLC
                    ("SAC Capital Advisors") with respect to shares of common
                    stock, par value $0.01 per share ("Shares"), of the Issuer
                    beneficially owned by S.A.C. Capital Associates, LLC ("SAC
                    Capital Associates") and S.A.C. Arbitrage Fund, LLC ("SAC
                    Arbitrage Fund"); (ii) S.A.C. Capital Management, LLC, ("SAC
                    Capital Management") with respect to Shares beneficially
                    owned by SAC Capital Associates and SAC Arbitrage Fund;
                    (iii) CR Intrinsic Investors, LLC ("CR Intrinsic Investors")
                    with respect to Shares beneficially owned by CR Intrinsic
                    Investments, LLC ("CR Intrinsic Investments"); and (iv)
                    Steven A. Cohen with respect to Shares beneficially owned by
                    SAC Capital Advisors, SAC Capital Management, SAC Capital
                    Associates, SAC Arbitrage Fund, CR Intrinsic Investors and
                    CR Intrinsic Investments.

                    SAC Capital Advisors, SAC Capital Management, CR Intrinsic
                    Investors and Steven A. Cohen have entered into a Joint
                    Filing Agreement, a copy of which is filed with this
                    Schedule 13G as Exhibit 99.1, pursuant to which they have
                    agreed to file this Schedule 13G jointly in accordance with
                    the provisions of Rule 13d-1(k) of the Securities Exchange
                    Act of 1934, as amended.

Item 2(b)           Address of Principal Business Office:
                    ------------------------------------

                    The address of the principal business office of (i) SAC
                    Capital Advisors, CR Intrinsic Investors and Mr. Cohen is 72
                    Cummings Point Road, Stamford, Connecticut 06902 and (ii)
                    SAC Capital Management is 540 Madison Avenue, New York, New
                    York 10022.

Item 2(c)           Citizenship:
                    -----------

                    SAC Capital Advisors, SAC Capital Management and CR
                    Intrinsic Investors are Delaware limited liability
                    companies. Mr. Cohen is a United States citizen.

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

                    Common Stock, par value $.01 per share


                                  Page 6 of 10





Item 2(e)           CUSIP Number:
                    ------------

                    91307C102

Item 3              Not Applicable

Item 4              Ownership:
                    ---------

                    The percentages used herein are calculated based upon the
                    Shares issued and outstanding as of April 27, 2007 as
                    reported on the Issuer's quarterly report on Form 10-Q filed
                    with the Securities and Exchange Commission for the
                    quarterly period ended March 31, 2007.

                    As of the close of business on July 18, 2007:

                    1. S.A.C. Capital Advisors, LLC
                    (a) Amount beneficially owned: 789,354 (1)
                    (b) Percent of class: 3.8% (1)
                    (c)(i) Sole power to vote or direct the vote: -0-
                    (ii) Shared power to vote or direct the vote: 789,354 (1)
                    (iii) Sole power to dispose or direct the disposition: -0-
                    (iv) Shared power to dispose or direct the disposition:
                    789,354 (1)

                    2. S.A.C. Capital Management, LLC
                    (a) Amount beneficially owned: 789,354 (1)
                    (b) Percent of class: 3.8% (1)
                    (c)(i) Sole power to vote or direct the vote: -0-
                    (ii) Shared power to vote or direct the vote: 789,354 (1)
                    (iii) Sole power to dispose or direct the disposition: -0-
                    (iv) Shared power to dispose or direct the disposition:
                    789,354 (1)

                    3. CR Intrinsic Investors, LLC
                    (a) Amount beneficially owned: 452,000 (2)
                    (b) Percent of class: 2.2% (2)
                    (c)(i) Sole power to vote or direct the vote: -0-
                    (ii) Shared power to vote or direct the vote: 452,000 (2)
                    (iii) Sole power to dispose or direct the disposition: -0-
                    (iv) Shared power to dispose or direct the disposition:
                    452,000 (2)

                    4. Steven A. Cohen
                    (a) Amount beneficially owned: 1,241,354 (3)
                    (b) Percent of class: 6.0% (3)
                    (c)(i) Sole power to vote or direct the vote: -0-
                    (ii) Shared power to vote or direct the vote: 1,241,354 (3)
                    (iii) Sole power to dispose or direct the disposition: -0-
                    (iv) Shared power to dispose or direct the disposition:
                    1,241,354 (3)


                                  Page 7 of 10





                    (1) Includes 509,354 Shares subject to call options held by
                    SAC Capital Associates.

                    (2) Includes 452,000 Shares subject to call options held by
                    CR Intrinsic Investments.

                    (3) Includes 509,354 Shares subject to call options held by
                    SAC Capital Associates and 452,000 Shares subject to call
                    options held by CR Intrinsic Investments.

                    SAC Capital Advisors, SAC Capital Management, CR Intrinsic
                    Investors and Mr. Cohen do not directly own any Shares.
                    Pursuant to investment management agreements, each of SAC
                    Capital Advisors and SAC Capital Management share all
                    investment and voting power with respect to the securities
                    held by SAC Capital Associates and SAC Arbitrage Fund.
                    Pursuant to an investment management agreement, CR Intrinsic
                    Investors maintains investment and voting power with respect
                    to the securities held by CR Intrinsic Investments. Mr.
                    Cohen controls each of SAC Capital Advisors, SAC Capital
                    Management and CR Intrinsic Investors. CR Intrinsic
                    Investments is a wholly owned subsidiary of SAC Capital
                    Associates. By reason of the provisions of Rule 13d-3 of the
                    Securities Exchange Act of 1934, as amended, each of (i) SAC
                    Capital Advisors, SAC Capital Management and Mr. Cohen may
                    be deemed to own beneficially 789,354(1) Shares
                    (representing approximately 3.8%(1) of the Shares
                    outstanding) and (ii) CR Intrinsic Investors and Mr. Cohen
                    may be deemed to own beneficially 452,000(2) Shares
                    (representing approximately 2.2%(2) of the Shares
                    outstanding). Each of SAC Capital Advisors, SAC Capital
                    Management, CR Intrinsic Investors and Mr. Cohen disclaim
                    beneficial ownership of any of the securities covered by
                    this statement, and SAC Capital Associates disclaims
                    beneficial ownership of any securities held by CR Intrinsic
                    Investments.

Item 5              Ownership of Five Percent or Less of a Class:
                    --------------------------------------------

                    If this statement is being filed to report the fact that as
                    of the date hereof the reporting person has ceased to be the
                    beneficial owner of more than five percent of the class of
                    securities, check the following. [ ]

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

                    Not Applicable


                                  Page 8 of 10





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

                    Not Applicable

Item 8              Identification and Classification of Members
                    --------------------------------------------
                    of the Group:
                    ------------

                    Not Applicable

Item 9              Notice of Dissolution of Group:
                    ------------------------------

                    Not Applicable

Item 10             Certification:
                    -------------

     By signing below the signatory certifies that, to the best of his knowledge
and belief, the securities referred to above were not acquired and are not held
for the purpose of or with the effect of changing or influencing the control of
the issuer of the securities and were not acquired and are not held in
connection with or as a participant in any transaction having that purpose or
effect.


                                  Page 9 of 10





                                    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.

Dated:  July 24, 2007

S.A.C. CAPITAL ADVISORS, LLC


By: /s/ Peter Nussbaum
   ----------------------------
Name:   Peter Nussbaum
Title:  Authorized Person


S.A.C. CAPITAL MANAGEMENT, LLC


By: /s/ Peter Nussbaum
   ----------------------------
Name:   Peter Nussbaum
Title:  Authorized Person


CR INTRINSIC INVESTORS, LLC


By: /s/ Peter Nussbaum
   ----------------------------
Name:   Peter Nussbaum
Title:  Authorized Person


STEVEN A. COHEN


By: /s/ Peter Nussbaum
   ----------------------------
Name:   Peter Nussbaum
Title:  Authorized Person


                                 Page 10 of 10