Federal drug regulators are scolding Procter & Gamble for adding Vitamin C to its Vicks cold formulas, a combination not allowed by federal regulations.
The Food and Drug Administration issued a warning to the consumer products company, saying medications like Vicks Nyquil and Dayquil have not been approved to contain vitamin C.
According to the agency, a panel of experts found "no study which demonstrated that vitamin C is unequivocally effective for the prevention or treatment of the common cold."
P&G advertising for Vicks says the vitamin "can help blunt" the effects of a cold.
The FDA is tasked with verifying marketing claims about drugs.
Calls placed to Cincinnati-based P&G were not immediately returned Wednesday.