What helps a stuffy nose: saline and time, not the pill decongestant

If your nose is blocked from a cold, the most useful thing to know is that the oral decongestant in most cold-and-sinus tablets — phenylephrine — works no better than a placebo, and US regulators moved in 2024 to pull it from the market for exactly that reason [s2] [s3]. What does modestly help is dull by comparison: saline, warm fluids, time, and a short course of a nasal spray. The congestion of a cold clears on its own within days regardless of what you take.

The pill that does not clear your nose

Phenylephrine is the active decongestant in a large share of the "non-drowsy" daytime cold and sinus pills sold on open shelves, where it replaced pseudoephedrine after that drug was moved behind the pharmacy counter. A 2007 systematic review and meta-analysis put the standard 10 mg oral dose to the test and found it did not reduce nasal airway resistance — an objective measure of blockage — any more than placebo, with a mean maximal difference of 10.1% (95% confidence interval −3.8% to 23.9%), an interval that includes zero [s2]. Patient-reported decongestion was not consistently better than placebo either [s2]. Only at 25 mg, well above the approved dose, did the drug reduce resistance by a significant 27.6% (95% CI 17.5% to 37.7%) [s2].

That evidence is what eventually caught up with the product. In November 2024 the US Food and Drug Administration issued a proposed order to amend its over-the-counter cough-and-cold monograph and remove orally administered phenylephrine as a nasal decongestant active ingredient "because they are not effective" [s3]. The decision does not concern phenylephrine's safety — it concerns whether the pill does the one thing it is sold to do.

The oral decongestant that does have an effect is pseudoephedrine, the ingredient now kept behind the counter. A Cochrane review of decongestants used alone for the common cold pooled 15 trials in 1,838 participants and found that multiple doses gave a small improvement in self-reported congestion, measured about three hours after the last dose (standardised mean difference 0.49, 95% CI 0.07 to 0.92) — but rated the evidence low quality and the clinical relevance of so small an effect unknown [s1]. A single dose could not be shown to help at all [s1]. The honest reading is that even the decongestant that works, works only a little.

What actually helps, and what to skip

Because a cold's congestion resolves on its own, the defensible aim is comfort while it does. Saline — sprays or rinses — is the low-risk mainstay, and its evidence is covered separately in the piece on nasal saline irrigation. Warm fluids, humidified air, and simply waiting are reasonable; none shortens the cold, but none carries the downside of a drug that does not work.

Topical decongestant sprays such as oxymetazoline are the fastest route to an open nose, but they come with a well-known trap: the Cochrane review found only limited evidence on their longer-term safety, which is why they are intended for short-term use only [s1]. Used for more than a few days they can drive rebound congestion — the nose blocks up again as the drug wears off, prompting more spraying — so they relieve a cold's few bad days but should not become a habit.

Two common misreadings are worth naming. A blocked nose is not a sign that a cold has "turned bacterial" and needs an antibiotic; most colds are viral start to finish, the point made in coverage of antibiotics and the common cold, and cold weather itself does not cause them, as the piece on whether cold weather causes colds sets out. And congestion that is seasonal, itchy, and paired with sneezing and watery eyes is more likely allergic rhinitis than a cold — a different problem, better treated with a steroid nasal spray or antihistamine than a decongestant, and worth telling apart, as in the guide to distinguishing cold, flu, COVID and RSV. Remedies like zinc lozenges sit on their own thin evidence base and do nothing for a blocked nose specifically.

When a stuffy nose is worth a look

The evidence here concerns the ordinary, self-limiting congestion of a common cold [s1]. Congestion that lasts well beyond ten days, keeps returning, or comes with facial pain and pressure, a high fever, thick discolored discharge that persists, or blood, falls outside that picture and can point to sinusitis or another cause worth a clinician's attention — as does a blockage on one side only, which should always be checked. Which treatment, if any, suits a given nose is a clinical judgement this article does not make; what the evidence settles is that the pill many reach for first is the one least likely to help.