Many Americans take both dietary supplements and prescription or over-the-counter drugs.
Sometimes, these drugs and supplements may interact in harmful ways.
It’s important to tell all your health care providers about all dietary supplements and drugs you take. That way, they can help you avoid harmful interactions.
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Some Supplements May Increase the Effects—and Side Effects—of Drugs
Sometimes, taking a drug and a supplement together may increase the drug’s effects. The drug’s effects may become too strong, and unwanted side effects may increase.

For example, the herb schisandra may slow down the processes in your body that change drugs into inactive substances. So if you take this herb while you’re also taking a drug, the amount of the drug in your body may increase. As a result, the drug’s effects may be too strong.
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Some Supplements May Decrease the Effects of Drugs
Sometimes, taking a drug and a supplement together may decrease the drug’s effects. This means that you aren’t getting the full benefit from the drug that your health care provider wants you to have.

One popular herbal supplement is especially well known for decreasing the effects of drugs. It does this by speeding up the processes in your body that change drugs into inactive substances. This herb may decrease the effectiveness of more than 70 percent of all drugs.
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Interactions With Over-the-Counter Drugs
When people think about drug interactions, they often think about prescription drugs.
But some drugs that are available over the counter without a prescription can interact with supplements, too.
If you’re considering taking both an over-the-counter drug and a dietary supplement, it’s a good idea to talk with your health care provider
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Read the entire article at https://nccih.nih.gov/health/know-science/how-medications-supplements-interact?nav=govd&page=8