Changes are coming to the cold and cough aisle of your local pharmacy: U.S. officials are moving to phase out the leading decongestant found in hundreds of over-the-counter medicines, concluding that it doesn鈥檛 actually relieve nasal congestion.

Phenylephrine is used in popular versions of Sudafed, Dayquil and other medications, but experts have long questioned its effectiveness. Last month the Food and Drug Administration revoking its use in pills and liquid solutions, kicking off a process that鈥檚 likely to force drugmakers to remove or reformulate products.

It鈥檚 a win for skeptical academics, including researchers at the University of Florida who petitioned the FDA to revisit the drug鈥檚 use in 2007 and again in 2015. For consumers it will likely mean switching to alternatives, including an older decongestant that was moved behind the pharmacy counter nearly 20 years ago.

Doctors say Americans will be better off without phenylephrine, which is often combined with other medicines to treat cold, flu, fever and allergies.

鈥淧eople walk into the drugstore today and see 55,000 medicines on the shelf and they pick one that is definitely not going to work,鈥� said Dr. Brian Schroer of the Cleveland Clinic. 鈥淵ou take away that option and it will be easier for them to self-direct toward products that really will help them.鈥�

Why is FDA doing this now?

The FDA decision was expected after federal advisers last year that oral phenylephrine medications haven鈥檛 been shown to relieve congestion.

Experts reviewed several recent, large studies indicating that phenylephrine was no better than a placebo at clearing nasal passageways. They also revisited studies from the 1960s and 1970s that supported the drug鈥檚 initial use, finding numerous flaws and questionable data.

The panel鈥檚 opinion only applied to phenylephrine in oral medications, which account for roughly $1.8 billion in annual U.S. sales. The drug is still considered effective in nasal sprays, though those are much less popular.

Phenylephrine wasn鈥檛 always the top choice for cold and allergy products. Many were originally formulated with a different drug, pseudoephedrine.

But a 2006 law required pharmacies to move pseudoephedrine products behind the counter, citing their potential to be processed into methamphetamine. Companies such as Johnson & Johnson and Bayer decided to reformulate their products to keep them readily available on store shelves 鈥� and labeled many of them as 鈥淧E鈥� versions of familiar brand names.

What are some alternatives for congestion?

Consumers who still want to take pills or syrups for relief will probably need to head to the pharmacy counter 鈥� where the pseudoephedrine-containing versions of Sudafed, Claritin D and other products remain available without a prescription. Purchasers need to provide a photo ID.

Beyond those products, most of the other options are over-the-counter nasal sprays or solutions.

Saline drops and rinses are a quick way to clear mucus from the nose. For long-term relief from seasonal stuffiness, itching and sneezing, many doctors recommend nasal steroids, sold as Flonase, Nasacort and Rhinocort.

鈥淭hese medicines are by far the most effective daily treatment for nasal congestion and stuffiness,鈥� Schroer said. 鈥淭he biggest issue is they鈥檙e not great when used on an as-needed basis.鈥�

Nasal steroids generally have to be used daily to be highly effective. For short-term relief, patients can try antihistamine sprays, such as Astepro, which are faster acting.

Phenylephrine-based sprays will also remain on pharmacy shelves.

Why doesn鈥檛 phenylephrine work when taken by mouth?

The experts who challenged the drug鈥檚 effectiveness say it鈥檚 quickly broken down and rendered ineffective when it hits the stomach.

鈥淭his is a good drug, but not when it鈥檚 swallowed,鈥� said Leslie Hendeles, professor emeritus at the University of Florida鈥檚 College of Pharmacy, where he co-authored several papers on the ingredient. 鈥淚t鈥檚 inactivated in the gut and doesn鈥檛 get into the bloodstream, so it can鈥檛 get to the nose.鈥�

When Hendeles and his colleagues first petitioned the FDA on phenylephrine, they suggested a higher dose might be effective. But subsequent studies showed that even doses 400% higher than those currently recommended don鈥檛 treat stuffiness.

The FDA and other researchers concluded that pushing the dosage even higher might carry safety risks.

鈥淚f you鈥檙e using very high doses, the risk is raising blood pressure so high that it could be hazardous to patients,鈥� said Randy Hatton, a University of Florida professor who co-led the research on phenylephrine.

Because of its cardiovascular effects, the drug is sometimes used to treat dangerously low blood pressure during surgery, Hatton noted.

What happens next?

Oral phenylephrine medicines will still be with us for a while.

Government regulators must follow a public, multistep process to remove the ingredient from FDA鈥檚 list of drugs approved for over-the-counter decongestants.

For six months, the FDA must take comments on its proposal, including from consumers and companies. Then, the FDA must review the feedback before writing a final order. Even after that decision is finalized, companies will likely have a year or more to remove or reformulate products.

Drugmakers could further delay the process by requesting additional FDA hearings.

For now, the Consumer Healthcare Products Association 鈥� which represents medicine makers 鈥� wants the products to stay available, saying Americans deserve 鈥渢he option to choose the products they prefer for self-care.鈥�

Hatton says he and his colleagues disagree: 鈥淥ur position is that choosing from something that doesn鈥檛 work isn鈥檛 really a choice.鈥�