Getting free samples of prescription medications from your doctor might sound like a great deal, but it’s a potentially risky practice for several reasons.

You might not get printed instructions. In general, free samples don’t show the side effects or precautions on the label, and you might not receive accompanying inserts. Other research has shown that oral instructions from physicians are insufficient to ensure proper drug use.

There’s no safety system. The medication won’t be entered into your pharmacy’s computer system, which screens for harmful interaction or duplication with other drugs and supplements you take, allergies you might have, and unacceptable doses. And you might not be alerted if a safety issue arises, such as a drug recall.

They might not be the best choice. Manufacturers typically use free samples to promote the newest, least-tested drugs. Such gifts might lead doctors to prescribe them when other drugs might be better.

The bottom line. Free drug samples aren’t necessarily a bargain. Before accepting them, ask your physician whether the medication is the best one for you or just a money-saver. If it’s the right one, ask him or her to describe, ideally in writing, how and when to take it, and its possible side effects. Then call your pharmacist to ask whether it can interact with any other medications or supplements you’re taking. And have the pharmacist add the drug to your online records.