According to federal health officials, there is only limited evidence that new formulations of over-the-counter cold medications actually relieve nasal congestion.
Studies of phenylephrine, which was recently added to many cold medicines, are all small, poorly designed and decades-old. Half of the few studies of phenylephrine did not even show significant improvement in nasal airflow.
According to University of Florida Professor Leslie Hendeles, the new formulations "aren't any better than taking nothing."