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                                                                    EXHIBIT 32.1

                    CERTIFICATION OF CHIEF EXECUTIVE OFFICER

            In connection with the Annual Report of Santarus, Inc. (the
"Company") on Form 10-K for the period ended December 31, 2004, as filed with
the Securities and Exchange Commission on the date hereof (the "Report"), I,
Gerald T. Proehl, President and Chief Executive Officer of the Company, certify,
pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the
Sarbanes-Oxley Act of 2002, that to my knowledge:

1.    The Report fully complies with the requirements of Section 13(a) or 15(d)
      of the Securities Exchange Act of 1934; and

2.    That information contained in the Report fairly presents, in all material
      respects, the financial condition and results of operations of the
      Company.

      Dated: March 23, 2005              /s/ GERALD T. PROEHL
                                         ---------------------------------------
                                         Gerald T. Proehl
                                         President and Chief Executive Officer

            The foregoing certification is being furnished solely to accompany
the Report pursuant to 18 U.S.C. Section 1350, and is not being filed for
purposes of Section 18 of the Securities Exchange Act of 1934, as amended, and
is not to be incorporated by reference into any filing of the Company, whether
made before or after the date hereof, regardless of any general incorporation
language in such filing. A signed original of this written statement required by
Section 906 has been provided to the Company and will be retained by the Company
and furnished to the Securities and Exchange Commission or its staff upon
request.

                    CERTIFICATION OF CHIEF FINANCIAL OFFICER

            In connection with the Annual Report of Santarus, Inc. (the
"Company") on Form 10-K for the period ended December 31, 2004, as filed with
the Securities and Exchange Commission on the date hereof (the "Report"), I,
Debra P. Crawford, Senior Vice President and Chief Financial Officer of the
Company, certify, pursuant to 18 U.S.C. Section 1350, as adopted pursuant to
Section 906 of the Sarbanes-Oxley Act of 2002, that to my knowledge:

1.    The Report fully complies with the requirements of Section 13(a) or 15(d)
      of the Securities Exchange Act of 1934; and

2.    That information contained in the Report fairly presents, in all material
      respects, the financial condition and results of operations of the
      Company.

      Dated: March 23, 2005              /s/ DEBRA P. CRAWFORD
                                         ---------------------------------------
                                         Debra P. Crawford
                                         Senior Vice President and Chief
                                         Financial Officer

            The foregoing certification is being furnished solely to accompany
the Report pursuant to 18 U.S.C. Section 1350, and is not being filed for
purposes of Section 18 of the Securities Exchange Act of 1934, as amended, and
is not to be incorporated by reference into any filing of the Company, whether
made before or after the date hereof, regardless of any general incorporation
language in such filing. A signed original of this written statement required by
Section 906 has been provided to the Company and will be retained by the Company
and furnished to the Securities and Exchange Commission or its staff upon
request.