The U.S. Food and Drug Administration (FDA) is proposing to remove a common ingredient in nasal decongestants used by millions of Americans, citing data that shows it’s not effective. Oral phenylephrine is used in over-the-counter products like Sudafed and Dayquil to help temporarily relieve the common symptom of colds and allergies.

Phenylephrine is both the most common decongestant on pharmacy shelves, and arguably the worst at its job. Last year, the FDA's advisory panel ruled it should no longer be considered an effective drug.

When you’re feeling under the weather, you likely grab your go-to cough and cold medicine. But are all the ingredients helping you fight off that cold?