Does Taking Sudafed Every Day Cause Rebound?

Oral decongestants like Sudafed (pseudoephedrine) generally do not cause rebound congestion like topical nose sprays do.


Hi, if I take one Sudafed at night before bed, can I do this each night without getting rebound? My nose only blocks at night, during the day it's not as bad.

Asked by Linda On Jan 01, 2019

Answered by
Medical Content Reviewed By PharmacistAnswers Staff

On Jan 03, 2019


Red Sudafed Pills

Oral decongestants, also known as 'systemic' decongestants, include Sudafed (pseudoephedrine) and Sudafed PE (phenylephrine). They produce little to no rebound congestion.

This is in stark contrast to topically applied decongestants, or nose sprays. These products include:

  • Afrin (oxymetazoline)
  • 4-Way Fast Acting Nasal Spray (Phenylephrine)

It is generally recommended to limit use of these products to a maximum of 2 to 3 days as they are well known to cause 'rebound congestion', also known as rhinitis medicamentosa.

This is a condition in which nasal congestion gets worse, even with continued use or an increased dose of your nasal spray.

Although rebound congestion typically only occurs with topical decongestant nose sprays, you'll often see oral decongestants, like Sudafed, lumped in as causative agents as well in articles discussing the condition.

There are even studies that list pseudoephedrine and phenylephrine as drugs that cause rebound congestion. However, this is mostly based on theoretical mechanisms and rarely do they reference a single study in which systemic therapy was known to cause it.

**It is important to note that phenylephrine is available in both an oral form and topical spray form. The topical form has been associated with rebound congestion, not the oral form.**

Medical sources that directly discuss whether or not systemic decongestants cause rebound congestion are generally succinct in the answer given (which is that they do not).

Middleton's Allergy Essentials, a reference for allergic disorders, simply states the following:

"Repetitive use of topical α-adrenergic decongestant nasal sprays (e.g., oxymetazoline, phenylephrine) for more than a few days may result in rebound nasal congestion, most likely secondary to downregulation of the α-agonist receptor. With long-term use of these agents, patients may develop a chronic form of rhinitis referred to as rhinitis medicamentosa."

It goes on to say:

"Oral decongestants do not cause rebound congestion but are not as effective as topical formulations."

All of this isn't to say that oral/systemic decongestants don't have their share of side effects and contraindications. But when it comes to rebound congestion, they are not typically associated with it like topical decongestants are.

Even the packaging for Sudafed doesn't contain a warning regarding limiting use like topical decongestants do. Below are labels for Sudafed, and Afrin nasal spray.

Sudafed 24 Hour Label

You will notice that the Sudafed label does not give any warnings about duration of use, outside of the statement to not continue use for over 7 days if symptoms don't improve. This is a general warning on all over the counter medications as not feeling better could be indicative of a more serious ailment.Afrin Nasal Spray Label Warning

Afrin however, has a clear warning about overuse causing rebound congestion.

There are several reasons why topical decongestants are more likely to cause rebound congestion when compared to systemic ones.

These reasons include the fact that topical sprays are applied right to the site of action, providing full potency, while systemic ones undergo a degree of metabolism. Phenylephrine has notoriously low bioavailability, with less than 40% of an oral dose being absorbed.

Additionally, a commonly used preservative in nasal sprays, benzalkonium chloride, has been linked to being a causative factor in rebound congestion. From one study:

"Benzalkonium chloride (BKC), a quaternary ammonium compound used as a preservative to prevent bacterial contamination in many nasal sprays, may increase the risk of developing RM [rhinitis medicamentosa] by inducing mucosal swelling."

In the next sections, I answer some other frequently asked questions about decongestants.

Answer Summary

Oral decongestants such as Sudafed (pseudoephedrine) and Sudafed PE (phenylephrine) are unlikely to cause rebound congestion with extended use.


FAQ Post It Notes

Below are some additional questions and answers about nasal decongestants.

How Do Decongestants Work?

Q: How do nasal decongestants work to remove mucus?

A: Nasal decongestants don't actually remove mucus or reduce production of mucus. Rather, they relieve inflammation and improve mucus drainage.

Without getting too technical (as each drug is slightly different), nasal decongestants either directly or indirectly stimulate alpha-receptors and increase the release of norepinephrine. This produces vasoconstriction, or a narrowing of blood vessels.

Vasoconstriction shrinks swollen mucous membranes in the nose, which promotes drainage and improves overall nasal airway ventilation.

Topical Rebound Congestion

Q: Why exactly do topical nasal decongestants cause a rebound effect?

A: The precise mechanism behind what causes rebound congestion isn't well understood. Some theories include:

  • Since nasal decongestants stimulate alpha-receptors and cause the release of norepinephrine, extended use can cause a negative feedback loop and down-regulation of these receptors. The net effect is a loss of vasoconstriction, resulting in congestion.
  • Vasoconstriction causes a lack of oxygen, known as ischemia. This can accelerate the formation of edema, or swelling, which makes it more difficult to breathe through the nose.
  • Systemic decongestants may have weak effects on beta-receptors. Unlike alpha-receptors, when beta-receptors are stimulated, vasodilation can occur. Due to a possible down-regulation of alpha-receptors, beta-receptor stimulation may be more prominent.

Sudafed Vs. Sudafed PE

Q: Is Sudafed (pseudoephedrine) or Sudafed-PE (phenylephrine) better?

A: While individual response may vary, Sudafed (pseudoephedrine) generally gives better results. This is likely due to the fact the phenylephrine is poorly absorbed from the GI tract.

In fact, several studies report that phenylephrine is no more effective than placebo in relieving nasal congestion:

"During a 6-hour observation period, a single dose of pseudoephedrine but not phenylephrine resulted in significant improvement in measures of nasal congestion"

Saline Spray Rebound

Q: Is it possible to experience rebound congestion from saline nasal sprays?

A: No, saline sprays will not cause rebound congestion. However, hypertonic saline sprays (those which contain over 0.9% NaCl) may cause excess dryness and stinging.

Oral Vs. Intranasal Safety

Q: Since Sudafed most likely won't cause rebound congestion, is it a safer option when compared to intranasal sprays?

A: Not necessarily. Oral decongestants have their own side effects, including:

  • Cardiovascular stimulation (e.g. increased blood pressure and heart rate)
  • Central nervous system stimulation (e.g. restlessness, insomnia, anxiety)
  • Decreased appetite and urinary retention

If you have any sort of heart condition, you should speak with your doctor prior to using decongestant products.

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  • ClinicalKey Drug Monograph: Pseudoephedrine (Accessed 1/2/19)
  • ClinicalKey Drug Monograph: Phenylephrine (Accessed 1/2/19)
  • ClinicalKey Drug Monograph: Oxymetazoline (Accessed 1/3/19)
  • Sudafed Manufacturer Webite (Accessed 1/3/19)
  • Afrin Manufacturer Website (Accessed 1/3/19)
  • Rebound congestion and rhinitis medicamentosa: Nasal decongestants in clinical practice. Critical review of the literature by a medical panel. ScienceDirect (Accessed 1/3/19)
  • Meta-analysis of the efficacy of a single dose of phenylephrine 10 mg compared with placebo in adults with acute nasal congestion due to the common cold. PubMed (Accessed 1/3/19)
  • Safety review of benzalkonium chloride used as a preservative in intranasal solutions: an overview of conflicting data and opinions. PubMed (Accessed 1/3/19)
  • A placebo-controlled study of the nasal decongestant effect of phenylephrine and pseudoephedrine in the Vienna Challenge Chamber. PubMed (Accessed 1/3/19)
  • Selecting a decongestant. PubMed (Accessed 1/3/19)
  • Rhinitis medicamentosa. PubMed (Accessed 1/3/19)
  • Comparison of the clinical efficacy of standard and mucoadhesive-based nasal decongestants. PubMed (Accessed 1/3/19)
  • Nasal decongestants in the treatment of chronic nasal obstruction: efficacy and safety of use. PubMed (Accessed 1/3/19)

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