Filed Pursuant to Rule 424(b)(3)
           Registration Nos. 333-108645, 333-111135, 333-113796 and 333-117178



                              PROSPECTUS SUPPLEMENT
                                    Number 1
                                       to
                         Prospectus dated August 2, 2004
                                       of
                           HEMISPHERX BIOPHARMA, INC.


On August 5,  2004,  we closed a private  placement  with  select  institutional
investors of approximately  3,617,300 shares of its Common Stock and warrants to
purchase an  aggregate  of up to  approximately  1,085,200  shares of its Common
Stock.  Portside  Growth & Opportunity  Fund,  one of the selling  stockholders,
purchased  961,539  shares and  288,462  warrants  in the  placement.  We raised
approximately $7,524,000 in gross cash proceeds from this private offering.

The Warrant issued to each purchaser is exercisable  for up to 30% of the number
of shares of Common Stock  purchased  by such  Purchaser,  at an exercise  price
equal to $2.86 per  share.  Each  Warrant  has a term of five years and is fully
exercisable from the date of issuance.

We  have  agreed  to  file  with  the  Securities  and  Exchange   Commission  a
registration  statement  covering resales of the shares issued to the purchasers
in the placement and shares issuable upon the exercise of the Warrants.

As a  result  of  the  placement,  the  conversion  prices  of  certain  of  the
outstanding  Debentures  and the exercise  prices of all of the warrants held by
the  debenture   holders  have  been  adjusted  pursuant  to  the  anti-dilution
provisions of these securities.  For information on the anti-dilution provisions
of these  securities,  see  "Management's  Discussion  and Analysis of Financial
Condition and Results of  Operations;  Liquidity  and Capital  Resources" in the
prospectus.


NEITHER  THE  SECURITIES  AND  EXCHANGE  COMMISSION  NOR  ANY  STATE  SECURITIES
COMMISSION HAS APPROVED OR  DISAPPROVED  OF THESE  SECURITIES OR PASSED UPON THE
ACCURACY OR ADEQUACY OF THIS PROSPECTUS  SUPPLEMENT.  ANY  REPRESENTATION TO THE
CONTRARY IS A CRIMINAL OFFENSE.



            The date of this Prospectus Supplement is August 6, 2004