It’s easy to understand how a medicine like phenylephrine got onto pharmacy shelves in the first place. The common decongestant, used most often as an ingredient in multidrug cold medications like DayQuil and Sudafed PE, was initially designated as “safe and effective” by the Food and Drug Administration (FDA) in 1976, when the agency was newly—and less stringently than today—greenlighting drugs that had been on the market for years before the agency had established any efficacy standards. After a full review of 14 studies (12 unpublished and two published) from pharmaceutical companies—a fair body of evidence for the time—the panel of experts assigned to evaluate over-the-counter allergy medications ruled that phenylephrine was effective.
Except phenylephrine has never worked. What’s puzzling, then, is how it stayed on those shelves for 50 years without a challenge. That changed on Sep. 12, when a different FDA advisory committee looking in part at that same early research voted 16-0 that the common oral form of phenylephrine is ineffective, opening the door for products claiming it works as a decongestant to be pulled from stores altogether. Though a final decision by agency authorities could take months and face legal challenges, the panel vote alone could be a death blow to the medication, which appears in products that together account for nearly $1.8 billion in U.S. spending each year.
Experts agree that an over-the-counter medication shouldn’t easily be able to go half a century without being reevaluated against new scientific standards. The FDA has since the late 1960s required that over-the-counter medications meet formal standards for both safety and efficacy, but since its initial market purge of medications that didn’t meet those criteria in the early 1970s, such approvals have really only been called into question over safety concerns. “In 50 years, I don’t ever remember a drug being removed from the market because it wasn’t effective,” says Leslie Hendeles, a professor emeritus at the University of Florida’s College of Pharmacy and an FDA consultant. In other words, if it isn’t broken, the FDA usually doesn’t have the bandwidth to fix it. The story of phenylephrine, then, isn’t just an example of the agency’s past oversights, but could be what Hendeles calls the “poster child” of a new effort to clean them up in every aisle.
Though it’s popular now, phenylephrine became the main over-the-counter decongestant through a sort of process of elimination. The 1976 panel that allowed it to stay on the market after the FDA updated its standards also approved two other decongestants: pseudoephedrine and phenylpropanolamine. The studies that formed the basis for phenylephrine’s approval were shaky by today’s standards; Hendeles says that the results are riddled with statistical anomalies, and that “some even had fraudulent data.”
At the time, phenylephrine was the least common of the three. Around the turn of the century, however, large studies began to demonstrate an association between phenylpropanolamine and dea