Dangers of taking supplements and prescription drugs

Taking supplements along with prescription medicines can be dangerous, according to Consumer Reports. But its investigation finds it's not easy for consumers to learn about the potentially harmful interactions.

We take $300 billion worth of prescription drugs a year and another 26 billion worth of dietary supplements.

Consumer reports medical advisor Dr. Orly Avitzur says combining the two may be hazardous to your health. "Some supplements can change the effectiveness of certain prescription drugs, and some can increase the likelihood and severity of side effects."

For example, glucosamine can interact with the blood thinner Warfarin and may increase the risk of bleeding.

St. John's wort can lower the effectiveness of oral contraceptives.

And if you regularly take the supplement Red Yeast Rice along with Lipitor or another prescription cholesterol drug, it may increase your risk of kidney or liver damage over time.

"Ideally, when getting a prescription, you should talk to your pharmacist about any supplements you're taking and see if there is a problem combining them," said Dr. Avitzur.

But when Consumer Reports sent anonymous shoppers into 20 pharmacies in five states to ask whether there was a potential problem taking Lipitor with Red Yeast Rice, many pharmacists didn't know.

"In 12 of the 20 times, pharmacists gave us incorrect or fuzzy advice. On two occasions, they actually recommended taking the combination." Dr. Avitzur added, "Besides talking to your pharmacist, you also want to consult with your doctor before taking any dietary supplements along with your prescription drugs," said Tod Marks from Consumer Reports.


Consumer Reports has put together a list of nine top-selling herbal supplements and some common drugs that may interact with them.

Print this article Back to Top