EXHIBIT 5.1

       [LETTERHEAD OF MINTZ, LEVIN, COHN, FERRIS, GLOVSKY AND POPEO, P.C.]

                                 November , 2002

Interleukin Genetics, Inc.
135 Beaver Street
Waltham, MA 02452

Ladies and Gentlemen:

            We have acted as counsel to Interleukin Genetics, Inc., a Delaware
corporation (the "Company"), in connection with the preparation and filing with
the Securities and Exchange Commission (the "Commission") of a Registration
Statement on Form S-3 (the "Registration Statement"), pursuant to which the
Company is registering under the Securities Act of 1933, as amended (the
"Securities Act"), an aggregate of 1,676,258 shares (the "Shares") of its common
stock, $0.001 par value per share (the "Common Stock"), which may be sold by the
selling stockholders named in the prospectus included in the Registration
Statement (the "Selling Stockholder"). The Company sold and issued the Shares to
the Selling Stockholders in private transactions.

            In connection with this opinion, we have examined the Company's
Certificate of Incorporation, as amended, and By-Laws, as amended; such other
records of the corporate proceedings of the Company and certificates of the
Company's officers as we have deemed relevant; and the Registration Statement
and the exhibits thereto. In our examination, we have assumed the genuineness of
all signatures, the legal capacity of natural persons, the authenticity of all
documents submitted to us as originals, the conformity to original documents of
all documents submitted to us as certified or photostatic copies and the
authenticity of the originals of such copies.

            Based upon the foregoing, we are of the opinion that, when sold by
the Selling Stockholders pursuant to the Registration Statement (including any
Prospectus Supplement relating thereto), and provided no stop order shall have
been issued by the Commission relating thereto, the Shares will be validly
issued, fully paid and non-assessable.

            Our opinion is limited to the General Corporation Law of the State
of Delaware (including the applicable provisions of the Delaware Constitution
and the reported judicial decisions interpreting such laws) and the federal laws
of the United States, and we express no opinion with respect to the laws of any
other jurisdiction. No opinion is expressed herein with respect to the
qualification of the Shares under the securities or blue sky laws of any state
or any foreign jurisdiction.

            It is understood that this opinion is to be used only in connection
with the offer and sale of the Shares while the Registration Statement is in
effect.

            We are opining only as to the matters expressly set forth herein,
and no opinion should be inferred as to any other matters. This opinion is based
upon currently existing statutes, rules, regulations and judicial decisions, and
we disclaim any obligation to advise you of any change in any of these sources
of law or subsequent legal or factual developments which might affect any
matters or opinions set forth herein.

            We hereby consent to the filing of this opinion with the Commission
as an exhibit to the Registration Statement in accordance with the requirements
of Item 601(b)(5) of Regulation S-K under the Securities Act and to the use of
this Firm's name therein and in the Prospectus under the caption "Legal
Matters." In giving such consent, we do not hereby admit that we are in the
category of persons whose consent is required under Section 7 of the Securities
Act or the rules and regulations of the Commission.

                                 Very truly yours,

                                 /s/ Mintz, Levin, Cohn, Ferris,
                                 Glovsky and Popeo, P.C.
                                 ---------------------------------
                                 Mintz, Levin, Cohn, Ferris,
                                 Glovsky and Popeo, P.C.