Exhibit 5.2

                                                                  April 10, 2001

Unigene Laboratories, Inc.
110 Little Falls Road
Fairfield, New Jersey 07004



Gentlemen:


     This opinion is being  furnished to you in connection with the filing today
of Amendment No. 2 to a Registration  Statement on Form S-1, File No.  333-54048
(the  "Registration  Statement")  being filed by Unigene  Laboratories,  Inc., a
Delaware   corporation  (the  "Company"),   with  the  Securities  and  Exchange
Commission  under the Securities Act of 1933, as amended,  for the  registration
for resale by Fusion  Capital Fund II, LLC  ("Fusion")  of 1,668,991  additional
(the  "Additional  Shares") of the Company's  common  stock,  par value $.01 per
share (the "Common Stock"). We previously by our letter, dated February 8, 2001,
furnished an opinion with respect to 7,331,009 of the 9,000,000 shares of Common
Stock that are being registered by the Registration Statement.

     The  Additional  Shares  that are  being  registered  for  resale by Fusion
consist of:

     (a)  668,991  shares of  Common  Stock  that have been  issued to Fusion as
addition compensation shares in consideration for its commitment, and

     (b) 1,000,000 shares of Common Stock that are issuable upon the exercise of
a Warrant,  dated as of March 31,  2001,  issued to Fusion by the  Company  (the
"Warrant") also as compensation for its commitment.

     For purposes of this opinion,  we have examined the Registration  Statement
(including  Amendment  No. 1 and  Amendment  No.  2) and the  relevant  exhibits
thereto, including:

         (1) the Common Stock Purchase Agreement, dated as of December 18, 2000,
between the Company and Fusion,

         (2) the First Amendment to Common Stock Purchase Agreement, dated as of
March 30, 2001, between the Company and Fusion (the "First Amendment"),

         (3) the Registration  Rights Agreement,  dated as of December 18, 2000,
between the Company and Fusion,

         (4) the  Registration  Rights  Agreement,  dated as of March 30,  2001,
between the Company and Fusion, and

     (e) the Warrant.

     We also have examined and relied upon a copy of the  Company's  Certificate
of Incorporation,  certified by the Secretary of State of the State of Delaware,




and copies of the Company's By-Laws and certain resolutions adopted by the Board
of Directors of the Company,  each  certified by the Corporate  Secretary of the
Company.

     We  further  have  examined  such  other  documents  and  made  such  other
investigations  as we have  deemed  necessary  to form a basis  for the  opinion
hereinafter expressed. In examining the foregoing documents, we have assumed the
authenticity of documents  submitted to us as originals,  the genuineness of all
signatures, the conformity to original documents of documents submitted to us as
copies, and the accuracy of the representations and statements included therein.

     Based on the foregoing, we are of the opinion that:

         (1) the  2,000,000  Additional  Shares  that been issued to Fusion have
been duly authorized and validly issued and are fully paid and nonassessable.

         (2) the  1,000,000  shares that are  issuable  upon the exercise of the
Warrant have been duly  authorized for issuance,  and, if and when issued,  sold
and  delivered  by the  Company  to Fusion in  accordance  with the terms of the
Warrant, will be validly issued, fully paid, and nonassessable.


               We hereby  consent to the filing of this opinion as an exhibit to
the Registration  Statement and to the use of our name in the Prospectus forming
a part thereof under the heading "Legal Matters."

                                                         Very truly yours,



                                                         /s/ Covington & Burling
                                                         -----------------------
                                                         COVINGTON & BURLING