WASHINGTON (AP) — Government advisers say the leading decongestant used by millions of Americans to treat nasal congestion doesn’t actually work.

The Food and Drug Administration convened an expert panel to review the latest data on phenylephrine.

That’s used in over-the-counter versions of Sudafed, Dayquil and most other cold and allergy medicines sold on pharmacy shelves.

Drugmakers reformulated their pills and solutions with the ingredient after a 2006 law required an older drug to be moved behind the counter.

But researchers have long questioned the ingredient’s effectiveness.

The FDA advisers say new studies show oral phenylephrine was no better than a placebo at relieving congestion.