Exhibit 5.1


                            [Dechart LLP Letterhead]

October 10, 2003

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

Re:  Registration Statement on Form S-1

Gentlemen and Ladies:

We have acted as special counsel to Unigene Laboratories, Inc., a Delaware
corporation (the "Company"), in connection with a Registration Statement on Form
S-1 (the "Registration Statement") being filed today by the Company with the
Securities and Exchange Commission under the Securities Act of 1933, as amended,
for the registration for resale of up to 10,000,000 shares of the Company's
common stock, par value $.01 per share (the "Common Stock"), by Fusion Capital
Fund II, LLC ("Fusion"), consisting of: (i) up to 8,500,000 shares of Common
Stock (the "Purchase Shares") issuable to Fusion pursuant to the Common Stock
Purchase Agreement, dated as of October 9, 2003, between the Company and Fusion
(the "Common Stock Purchase Agreement"); (ii) up to 500,000 shares of Common
Stock (the "Warrant Shares") issuable to Fusion upon the exercise of a warrant
(the "Warrant") issued to Fusion pursuant to the Common Stock Purchase
Agreement; and (iii) up to 1,000,000 shares of Common Stock (the "Commitment
Shares") issuable to Fusion by the Company pursuant to the Common Stock Purchase
Agreement.

For purposes of this opinion, we have examined the Registration Statement and
the relevant exhibits thereto, including the Common Stock Purchase Agreement and
the Registration Rights Agreement between Fusion and the Company dated October
9, 2003 (the "Registration Rights Agreement").

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

We 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
authenticity of



the originals of such documents, and the accuracy of the representations and
statements included therein.

Based on the foregoing, and subject to the assumptions and qualifications set
forth herein, we are of the opinion that (i) the Purchase Shares have been duly
authorized for issuance, and when the certificates representing the Purchase
Shares in the form of the specimen certificate examined by us have been
countersigned by an authorized officer of the transfer agent for the Company,
and when issued and delivered by the Company to Fusion in accordance with the
terms of the Common Stock Purchase Agreement, the Purchase Shares will be
validly issued, fully paid and non-assessable; (ii) the Warrant Shares have been
duly authorized for issuance; and when the certificates representing the Warrant
Shares in the form of the specimen certificate examined by us have been
countersigned by an authorized officer of the transfer agent for the Company,
and when issued and delivered by the Company to Fusion upon exercise and against
payment in full as provided in the Warrant, the Warrant Shares will be validly
issued, fully paid and non-assessable; and (iii) the Commitment Shares have been
duly authorized for issuance; and when the certificates representing the
Commitment Shares in the form of the specimen certificate examined by us have
been countersigned by an authorized officer of the transfer agent for the
Company, and when issued and delivered by the Company to Fusion in accordance
with the terms of the Common Stock Purchase Agreement, the Commitment Shares
will be validly issued, fully paid and non-assessable.

We express no opinion as to the applicability of, compliance with, or effect of
federal law or the law of any jurisdiction other than the General Corporation
Law of the State of Delaware.

We hereby consent to the filing of this opinion as an exhibit to the
Registration Statement and to the use of out name in the Prospectus contained
therein under the caption "Legal Matters." In giving such consent we do not
admit that we are in the category of persons whose consent is required under
Section 7 of the Securities Act or under the rules and regulations promulgated
by the Securities and Exchange Commission.

very truly yours,

/s/ Dechert LLP