Decongestants. Decongestants, such as Sudafed, are often used with allergies to constrict blood vessels in the nose and relieve the running nose. Pseudoephedrine, found in Sudafed, is approved for use while flying. This medication acts throughout the entire body by constricting blood vessels.

In 2026, whether a pilot can take Sudafed (pseudoephedrine) depends strictly on the regulations of the aviation authority governing their license, such as the FAA (US) or CAA (UK). In the United States, the FAA generally permits the use of Sudafed, but with a critical caveat: a pilot must not fly for a specific period (usually twice the dosing interval) after taking any medication to ensure no side effects like "brain fog" or dizziness occur. In the UK and Europe, the CAA is often more restrictive; while pseudoephedrine is technically allowed, it is discouraged because it can mask the symptoms of a cold that could lead to a painful "ear block" or sinus barotrauma during rapid pressure changes. Furthermore, the non-drowsy version of Sudafed (which contains phenylephrine) is often viewed differently than the "original" formula. Most importantly, pilots are strictly prohibited from taking "Sudafed PE" or any multi-symptom cold medicine that contains sedating antihistamines like diphenhydramine. Any pilot taking medication should consult their Aviation Medical Examiner (AME) to ensure they remain "fit to fly" and compliant with the latest 2026 safety protocols.