Stuffy Nose? This OTC Decongestant Doesn't Work

Find out what OTC medicine to skip when you have a cold—and what to do instead.

A woman with congestion blows her nose because her over-the-counter decongestant doesn’t work.

Updated on September 16, 2022.

When it’s bad enough, a stuffy nose can send you scrambling to the drugstore, scouring the shelves for a decongestant. And while many over-the-counter (OTC) decongestants market themselves as offering temporary relief, researchers say that one in particular—oral phenylephrine—doesn't work at all. 

Oral phenylephrine is an ingredient in thousands of common drugstore medications. In a 2015 study published in The Journal of Allergy and Clinical Immunology: In Practice, scientists enlisted 539 adults to test its efficacy. Some participants received oral phenylephrine in various dosages every four hours. Others took a placebo that did not contain any oral phenylephrine. In the end, researchers found that the drug was no better than the placebo for clearing clogged nasal passages. In fact, nearly 20 percent of people who took oral phenylephrine reported adverse side effects, such as headaches.

This wasn’t the first time it’s come up short in studies. “Two trials in 2009 had the same result,” says Keith Roach, MD, an associate professor in clinical medicine in the division of general medicine at Weill Cornell Medical College and New York-Presbyterian Hospital in New York City. “It’s not a good drug.” 

What is oral phenylephrine? 

Oral phenylephrine was determined to be safe by the U.S. Food and Drug Administration (FDA) in 1976. It was originally intended as a replacement for pseudoephedrine, a decongestant often used in the illegal production of methamphetamine.

Due to findings showing that oral phenylephrine is an ineffective decongestant, however, many have called on the FDA to remove it from the market. 

“The drug companies say taking this medicine will make you feel better,” says Dr. Roach. “But you can feel better taking a placebo without the risk of serious side effects. I can give you a sugar pill with nothing in it and for some people, it works.” 

Possible side effects of phenylephrine include headache, nervous system disorders, nausea, and gastrointestinal disorders. Roach also mentions an additional side effect: "acute urinary retention, meaning you can’t pee even though your bladder is full.” This can be a problem especially for older men with enlarged prostates. 

“You could end up in the ER needing a tube in your bladder,” Roach says. “It can also raise your heart rate and blood pressure as well as make you jittery. In some people this can be quite pronounced.” 

How to help prevent and treat a stuffy nose 

Prevention is key to avoiding congestion and other cold and flu symptoms. Your first line of defense? “Get your flu shot,” says Roach. You can also: 

  • Practice good hygiene and wash your hands frequently. 
  • Avoid touching your mouth, nose, and eyes. These are prime entry points for germs. 
  • Get enough sleep. Skimping on your ZZZ's can weaken your immune system. 
  • Manage stress. When you’re stressed out, your body releases more of the hormone cortisol, which suppresses the immune system and makes it harder for your body to fend off infection. 
  • Eat healthy foods and exercise regularly. 
  • If possible, avoid being around people who are sick, or at least try to keep a safe distance. 

If you do pick up a bug, read product labels carefully before choosing an OTC medicine for your stuffy nose. Roach recommends choosing products that contain the decongestant pseudoephedrine and loratadine, an antihistamine. Pseudoephedrine can be found in drugs like Sudafed, SudoGest, and Wal-Phed D. 

Guaifenesin, found in Mucinex, may also work to thin the mucus and help you breathe easier. Some allergists put patients on it year-round as it has few drug interactions or side effects. Nasal steroids can be temporarily helpful, too. 

Another medication Roach recommends is montelukast. But you won’t find it on drugstore shelves. “You’ll need a prescription,” he says. 

Whichever you choose, each medication can be effective in helping you breathe easier.

Article sources open article sources

Hatton RC, Hendeles L. Why Is Oral Phenylephrine on the Market After Compelling Evidence of Its Ineffectiveness as a Decongestant? Ann Pharmacother. 2022 Mar 25:10600280221081526. 
Tietze, K. "Update: Safety and efficacy of oral phenylephrine still in question." Pharmacy Today 22, no. 9 (2016): 14.
Horak F, Petra Z, et al. “A placebo-controlled study of the nasal decongestant effect of phenylephrine and pseudoephedrine in the Vienna Challenge Chamber.” Annals of allergy, asthma & immunology: official publication of the American College of Allergy, Asthma, & Immunology 102 2 (2009): 116-20.
Hendeles L & Hatton RC. "Oral phenylephrine: an ineffective replacement for pseudoephedrine?." Journal of allergy and clinical immunology 118, no. 1 (2006): 279-280.
Meltzer EO, Ratner, PH et al. "Oral phenylephrine HCl for nasal congestion in seasonal allergic rhinitis: a randomized, open-label, placebo-controlled study." The Journal of Allergy and Clinical Immunology: In Practice 3, no. 5 (2015): 702-708.
Katsu Y and Baker ME. "Cortisol." In Handbook of hormones, pp. 947-949. Academic Press, 2021.
US Food & Drug Administration. Legal Requirements for the Sale and Purchase of Drug Products Containing Pseudoephedrine, Ephedrine, and Phenylpropanolamine. November 24, 2017.

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