I was going to say that this would fall under 'The Americans with Disabilities Act.' And that refusal of the coverage and employment would be considered discrimination. Well, I read through and found section 510 which gives an employer / insurance company a loophole. Of course, if it is a rehabiliation program, that's a different story. Either way, I'd go with the prohormone excuse.
http://www.usdoj.gov/crt/ada/pubs/ada.txt
SEC. 510. ILLEGAL USE OF DRUGS.
(a) In General.--For purposes of this Act, the term "individual with a
disability" does not include an individual who is currently engaging in the
illegal use of drugs, when the covered entity acts on the basis of such use.
(b) Rules of Construction.--Nothing in subsection (a) shall be construed to
exclude as an individual with a disability an individual who--
(1) has successfully completed a supervised drug rehabilitation program
and is no longer engaging in the illegal use of drugs, or has otherwise
been rehabilitated successfully and is no longer engaging in such use;
(2) is participating in a supervised rehabilitation program and is no
longer engaging in such use; or
(3) is erroneously regarded as engaging in such use, but is not
engaging in such use;
except that it shall not be a violation of this Act for a covered entity to
adopt or administer reasonable policies or procedures, including but not
limited to drug testing, designed to ensure that an individual described in
paragraph (1) or (2) is no longer engaging in the illegal use of drugs;
however, nothing in this section shall be construed to encourage, prohibit,
restrict, or authorize the conducting of testing for the illegal use of
drugs.
(c) Health and Other Services.--Notwithstanding subsection (a) and section
511(b)(3), an individual shall not be denied health services, or services
provided in connection with drug rehabilitation, on the basis of the current
illegal use of drugs if the individual is otherwise entitled to such
services.
(d) Definition of Illegal use of drugs.--
(1) In general.--The term "illegal use of drugs" means the use of
drugs, the possession or distribution of which is unlawful under the
Controlled Substances Act (21 U.S.C. 812). Such term does not include the
use of a drug taken under supervision by a licensed health care
professional, or other uses authorized by the Controlled Substances Act
or other provisions of Federal law.
(2) Drugs.--The term "drug" means a controlled substance, as defined in
schedules I through V of section 202 of the Controlled Substances Act.