EXHIBIT 5


September 24, 2002

Esperion Therapeutics, Inc.
3621 South State Street
695 KMS Place
Ann Arbor, MI 48108

Ladies and Gentlemen:

We have acted as counsel to Esperion Therapeutics, Inc., a Delaware corporation
(the "Company"), in connection with the preparation of a registration statement
on Form S-8 (the "Registration Statement") to be filed pursuant to the
Securities Act of 1933, as amended (the "Act"), and relating to 1,369,000 shares
of common stock of the Company, par value $0.001 per share (the "Shares"). The
Shares covered by the Registration Statement will be issued pursuant to the
Esperion Therapeutics, Inc. 2000 Equity Compensation Plan, as Amended and
Restated (the "Plan").

We have examined the Registration Statement and such corporate records, statutes
and other documents as we have deemed relevant in rendering this opinion. As to
matters of fact, we have relied on representations of officers of the Company.
In our examination, we have assumed the genuineness of documents submitted to us
as originals and the conformity with originals of documents submitted to us as
copies thereof.

Based on the foregoing, it is our opinion that, when issued and delivered in
accordance with the terms and conditions of the Plan, the Shares will be validly
issued, fully paid and nonassessable.

We hereby consent to the filing of this opinion as an exhibit to the
Registration Statement. In giving such consent, we do not thereby admit that we
come within the category of persons whose consent is required under Section 7 of
the Act or the rules or regulations of the Securities and Exchange Commission
thereunder.

Very truly yours,


MORGAN, LEWIS & BOCKIUS LLP