What Are Decongestants?

Medications used to relieve stuffiness due to allergies and illness

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A decongestant is a medication that clears up congestion. Congestion is another name for a stuffy head or nose. Most over-the-counter (OTC) decongestants contain either pseudoephedrine or phenylephrine.

When you feel stuffy, it's natural to expect a decongestant to help. But it might not always be the right choice.

This article will walk you through the types of decongestants and how they work. It will also help you understand the risks and side effects of using decongestants.

Closeup woman pouring medication or antipyretic syrup from bottle to cup
spukkato / Getty Images


Decongestants work best for minor congestion from:

They may not work as well for a bacterial infection. For that you need antibiotics. If you still have stuffiness after taking antibiotics, decongestants may help.

How Decongestants Work

You get stuffed up because of enlarged blood vessels ​in your nasal and airway membranes. These enlarged blood vessels make it hard to breathe and can trap mucus.

Decongestants narrow blood vessels. This lets mucus drain so you can breathe.

Types of Decongestants

Over-the-counter decongestants come in nasal sprays and in oral forms such as:

  • Pills
  • Tablets
  • Capsules
  • Liquids

Common decongestants include:

Nasal sprays work faster than oral decongestants. Don't use them for longer than recommended, though. They can irritate your nasal passages and make congestion worse.

Combination products like Tylenol Sinus, Advil Cold & Sinus, and Aleve Cold & Sinus also contain pain relievers. These medicines may help with sinus headaches from congestion.

Always follow the dosage instructions on the label or from your healthcare provider.

You can use most decongestants three to four times a day. Extended-release versions are used once or twice a day.

Sudafed (Pseudoephedrine)

Sudafed and its active ingredient, pseudoephedrine, come in several forms:

  • Regular tablets
  • 12-hour and 24-hour extended-release tablets
  • Liquid solution

Generic pseudoephedrine is also included in many multi-drug cold and flu products.

Buying Pseudoephedrine

Pseudoephedrine is technically available over the counter. You don't need a prescription, but its sale is restricted because some people use it to make methamphetamine (the illegal drug better known as "meth").

To buy pseudoephedrine, you must:

  • Ask for it at the pharmacy counter
  • Show your photo ID

Know that there is a limit to how much you can purchase per day and month.

Other brand-name drugs that contain pseudoephedrine include:

  • Contac Cold
  • Drixoral Decongestant Non-Drowsy
  • Kid Kare Drops
  • Nasofed
  • Sudodrin
  • Suphedrin
  • Unifed

This drug also prevents ear problems from pressure changes. This can be helpful for those why fly or scuba dive.

Sudafed PE (Phenylephrine)

Sudafed PE and generic phenylephrine are available in different forms:

  • Tablet
  • Liquid cough medicine
  • Quick-dissolve strip

Phenylephrine is also in many combination cold and flu products. Because it constricts blood vessels, it's also used in some hemorrhoid treatments.

Other brand name products with phenylephrine include:

  • Actifed Cold and Allergy
  • Advil Congestion Relief
  • Pediacare Children’s Decongestant
  • Suphedrin PE

Sales of phenylephrine are not restricted, so you should be able to find it on the shelf with other cold and flu remedies.

Afrin Nasal Spray (Oxymetazoline)

Afrin and many other nasal sprays contain oxymetazoline. This drug is used for congestion and to relieve nasal discomfort from colds and seasonal allergies.

The dosing schedule is typically every 10 hours or every 12 hours.

Other sprays that contain oxymetazoline include:

  • Anefrin Nasal Spray
  • Dristan Nasal Spray
  • Mucinex Nasal Spray
  • Vicks Sinex Nasal Spray
  • Zicam Nasal Spray

It's also used in many generic nasal sprays.


Most people can safely use decongestants, but they aren’t for everyone. Don't take decongestants if you have:

Some products contain a decongestant and a painkiller. Check the label before taking these with any other drugs. This will help keep you from taking too much of any one medication.

Always tell your healthcare provider about all medications you take, including OTC drugs. This can help you avoid possibly dangerous side effects and drug interactions.

If you’re pregnant, trying to get pregnant, or breastfeeding, talk to your healthcare provider before taking decongestants.

Warning: Use in Children

Don't give decongestants to children under 6. Before giving them to kids between 6 and 12, talk to their healthcare provider.

Decongestant Side Effects

Decongestants may cause mild side effects. These include:

  • Nausea or vomiting
  • Nervousness
  • Restlessness
  • Weakness
  • Headaches
  • Dry mouth

Side effects specific to nasal sprays include:

  • Burning, stinging, or dryness inside the nostrils
  • Increased nasal discharge
  • Sneezing

These more serious side effects are uncommon, but important to be aware of. If you experience any, report them to your healthcare provider immediately:

  • Anxiety
  • Elevated blood pressure
  • Changes in heart rate or rhythm
  • Insomnia
  • Tremors
  • Severe dizziness or fainting
  • Numbness or pain in hands or feet
  • Hallucinations
  • Seizures
  • Psychosis
  • Trouble urinating

Decongestants may also contribute to strokes and bleeding inside the skull.

Decongestants are chemically related to adrenaline, your body’s natural decongestant and stimulant. Caffeine may enhance the stimulant effect and worsen side effects of these drugs. Watch for nervousness and trouble sleeping.


Decongestants narrow the swollen blood vessels that cause congestion. They work best against stuffiness caused by allergies or viruses.

Decongestants come in many forms, including tablets, liquids, and nasal sprays. Always follow the dosage directions. When using multi-drug products, make sure you aren't taking other drugs with the same ingredients.

Check with your healthcare provider about use in children, during pregnancy and breastfeeding, and with chronic conditions. Contact your healthcare provider if you have any severe side effects.

A Word From Verywell

Decongestants can help you get relief from your stuffed-up nose. Because oral decongestants can cause side effects like restlessness, they may not be a good choice to relieve congestion at bedtime.

Fortunately, there are other things you can do to help relieve congestion. Staying hydrated can help loosen mucus. Take a hot shower before bed, breathing in the steam, and sleep with your head slightly elevated.

9 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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  2. InformedHealth.org. Treating acute sinusitis.

  3. U.S. National Library of Medicine. Oxymetazoline nasal spray.

  4. U.S. National Library of Medicine. Pseudoephedrine.

  5. U.S. National Library of Medicine. Phenylephrine.

  6. Deckx L, De Sutter AI, Guo L, Mir NA, van Driel ML. Nasal decongestants in monotherapy for the common coldCochrane Database Syst Rev. 2016;10(10):CD009612. doi:10.1002/14651858.CD009612.pub2

  7. Malone M, Kennedy TM. Review: side effects of some commonly used allergy medications (decongestants, anti-leukotriene agents, antihistamines, steroids, and zinc) and their safety in pregnancy. Int J Aller Medications. 2017;3(1). doi:10.23937/2572-3308.1510024

  8. Barton Health. Pseudoephedrine.

  9. Shao IH, Wu CC, Tseng HJ, Lee TJ, Lin YH, Tam YY. Voiding dysfunction in patients with nasal congestion treated with pseudoephedrine: a prospective study. Drug Des Devel Ther. 2016;10:2333-9. doi:10.2147/DDDT.S108819

Additional Reading

By Kristina Duda, RN
Kristina Duda, BSN, RN, CPN, has been working in healthcare since 2002. She specializes in pediatrics and disease and infection prevention.