The over-the-counter staples, known by brand names like Sudafed and Vicks ... use the drug to breathe normally, even if the congestion from mucus has reduced. Dr Sooj revealed one method ...

Does phenylephrine work? Doctors explain how to choose between cold medicines like Dayquil and Sudafed PE for congestion, ...

Essentially, decongestants work to shrink swollen blood vessels in the nasal cavity, which is what causes congestion. Caffeine, also found in tablets like Sudafed, can have a similar effect.