Joint Filing Agreement

Exhibit 99.1

                             Joint Filing Agreement

      This will confirm the agreement by and among all the undersigned that the
Amendment No. 1 to the Schedule 13D filed on or about this date and any
amendments thereto with respect to the beneficial ownership by the undersigned
of shares of the Common Stock of Restoragen, Inc. is being filed on behalf of
each of the undersigned. This agreement may be executed in two or more
counterparts, each of which shall be deemed an original, but all of which
together shall constitute one and the same instrument.

Dated as of January 24, 2003

                                       EQUITYFOURLIFE (BAHAMAS) LTD.

                                       By: /s/ Saurin Pirjo
                                           -------------------------
                                       Name: Saurin Pirjo
                                       Title: Director

                                       By: /s/ Xxxxxxx Xxxxxx-Xxxxx
                                           -------------------------
                                       Name: Xxxxxxx Xxxxxx-Xxxxx
                                       Title: Director


                                       EQUITY4LIFE AG

                                       By: /s/ Xxxxx Xxxxxx
                                           -------------------------
                                       Name: Xxxxx Xxxxxx
                                       Title:

                                       By: /s/ Xxxxxxx Xxxxxx
                                           -------------------------
                                       Name: Xxxxxxx Xxxxxx
                                       Title:


                                       XXXXXX XXXXXXXX

                                       /s/ Xxxxxx Xxxxxxxx
                                       -----------------------------


                                       XXXXX XXXXXX
                                       -----------------------------

                                       /s/ Xxxxx Xxxxxx


                                       ROCKY MOUNTAIN ASSOCIATES S.A.

                                       By: /s/ Pablo Xxxxxx Xxxxxx
                                           -------------------------
                                       Name: Pablo Xxxxxx Xxxxxx
                                       Title: Director

                                       By: /s/ Xxxxxxx X. xx Xxxxxxx
                                           -------------------------
                                       Name: Xxxxxxx X. xx Xxxxxxx
                                       Title: Director


                                       GOLDEN MEAN VENTURESS LTD.

                                       By: /s/ Xxxxx Xxxxxxxxxx
                                           -------------------------
                                       Name: Xx. Xxxxx Xxxxxxxxxx
                                       Title: Chairman of the Board of Directors


                                       XXXXXX XXXXXXXXXXX

                                       /s/ Xxxxxx Xxxxxxxxxxx
                                       -----------------------------