An FDA medical advisory panel ruled that phenylephrine (PE), a key ingredient in many over-the-counter cold medications, does not actually work to treat nasal congestion when taken orally at the recommended 10 mg dose every 4 hours. Phenylephrine was last evaluated for over-the-counter use as an oral and intranasal decongestant in 1976, according to the panel. If you're keeping score at home, that means many of the OTC decongestants consumers in the US have been buying for nearly the last 50 years were, according to the FDA, "failed to provide any benefit over [a] placebo."
This determination will impact drug makers that use PE as an active ingredient, which can be found in Sudafed, Vicks Sinex, and Benadryl Allergy Plus Congestion, for example.