The U.S. Food and Drug Administration has proposed to remove oral phenylephrine, widely used in cold and cough syrups, as an active ingredient in over-the-counter drugs for nasal congestion, stating it is not effective, the health regulator said on Thursday.

Phenylephrine is widely used in a variety of over-the-counter flu and cold medicines, including popular products such as Benadryl, Advil, and Tylenol.

It is also an ingredient in nasal sprays to treat congestion. However, the FDA's action is only related to orally administered phenylephrine and not the nasal spray form.

Last year, an outside panel of experts unanimously voted against the effectiveness of orally administered phenylephrine as a nasal decongestant, adding that no more trials were required to prove otherwise.

Companies such as Procter & Gamble and GSK were among several accused in lawsuits of deceiving consumers about cold medicines containing the ingredient.

The FDA is now seeking public comments on this proposed order.

For now, companies may continue to market drug products containing oral phenylephrine as a nasal decongestant.

However, the FDA said it would provide manufacturers with appropriate time to either reformulate drugs containing oral phenylephrine or remove such drugs from the market.

Tylenol maker Kenvue, GSK, Haleon , and Procter & Gamble did not immediately respond to Reuters' request for comment.