Graham has spent his career at the FDA studying the safety of drugs, many of them after approval using data from medical insurance companies. He claims successes in removing from the U.S. market the unsafe drugs Omniflox an antibiotic, Rezulin, a diabetes treatment, Fen-Phen and Redux, weight-loss drugs, and phenylpropanolamine, an over-the-counter decongestant, and in restricting the use of Trovan, an antibiotic, to use in hospitals. He also had a part in the removal of Lotronex, Baycol, Seldane, and Propulsid.
On November 18, 2004, Dr. Graham testified before the U.S. Senate Committee on Finance about Merck's withdrawal of the popular anti-inflammatory drug Vioxx the previous month because of serious safety concerns. In his testimony, he asserted that the policies within the U.S. Food and Drug Administration were insufficient to protect the public from drugs which carry unacceptable risks, saying "I would argue that the FDA, as currently configured, is incapable of protecting America against another Vioxx. We are virtually defenseless."
After his testimony, Graham was publicly criticized by the FDA. He contacted the nonprofit Government Accountability Project, a whistleblower protection organization, for advice on getting his findings on Vioxx published over the objections of his superiors. Tom Devine, of the GAP, told the Washington Post that "anonymous" callers contacted the GAP, apparently working in concert, trying to discredit or "smear" Graham, calling him "a demagogue and a bully" and his findings "junk science".