Nearly every commercial break on TV now includes drug ads that list dozens of possible side effects and outcomes. No matter how different these lists may be, though, every ad includes the phrase “ask your doctor.” Now new research is showing that asking doctors about certain medications really can influence their prescription.

A new study published in the journal Medical Care has found that this type of direct-to-consumer (DTC) marketing of brand-name drugs actually does significantly influence a doctor’s decision to prescribe those medications. The study results throw fuel into the debate over such marketing, raising questions about medical ethics and patient safety.

“A patient request for a specific medication dramatically increases the rate at which physician s prescribe that medication,” wrote the study’s authors. “These results highlight potential negative impacts of DTC advertising and other forms of activation in medication requests.”

The study used videos of actors who described specific painful medical conditions. Some requested oxycodone, some Celebrex, and others simply wanted “just something to make it better.” These videos were randomly shown to nearly 200 primary care physicians, who then gave their diagnosis for a patient.

Around 50% of the patients who requested Celebrex were prescribed the drug, opposed to only around 25% of those who requested nothing specific. Those who requested oxycodone received the strong narcotic at around a 20% rate while those with no brand request received oxycodone only 1% of the time.

“Supporters defend [DTC advertising] as a way to empower consumers, while opponents argue that commercially motivated messages leads to inappropriate patient requests for medication,” said Dr G. Caleb Alexander, deputy editor of Medical Care. “In order to resolve this debate, more research is needed to determine the effects of DTC advertising on patient and physician behavior, especially how it affects prescribing decisions and health outcomes.”