Prescription drugs can be very expensive in the U.S., and one way some people try to cut costs is by purchasing medicine from Canada instead. You can purchase medicines from online Canadian pharmacies, or you can travel across the border to purchase them in-person if you live close enough.

Although saving money by buying medicine in Canada may seem like a foolproof plan, there are some risks and downsides. Before you decide between the U.S. and Canada for filling a prescription, you should weigh the pros and cons. Here are three considerations when deciding whether or not to purchase medicine from Canadian pharmacies:

Legality

Personal importation, which is the act of bringing a prescription drug into the U.S. for personal use, is illegal. This applies even to FDA-approved drugs and to drugs that were manufactured in the U.S. before being shipped to a foreign country.

This is because the FDA can’t control what happens to drugs outside of the United States. Not all countries have such strict laws about drug manufacturing, and medicines manufactured outside of the U.S. might not meet the FDA’s requirements. Drugs that were manufactured in the U.S. and were imported could have been improperly stored or distributed, so the FDA does not want those drugs to reenter the U.S.

The FDA is very strict about medicines that are brought by companies to the U.S. to be sold or distributed. However, the FDA doesn’t usually enforce these laws on individuals who bring medicines into the country for personal use. It’s common for the FDA to look the other way in these situations, and there are no reports of Americans being prosecuted for buying medicines from foreign pharmacies.

If you buy medicine from a Canadian pharmacy and bring it into the United States, you will be breaking the law. This law is not strictly enforced, though, so you can decide whether you want to take the risk.

Safety

There are definite safety risks when buying medicine from a foreign pharmacy, especially if you buy from an online pharmacy. Although legitimate online pharmacies exist, many send out poor quality, ineffective, or counterfeit drugs. The medicine might have too little or too much of the active ingredient, or it might not contain the active ingredient at all. It could be old, or it could have lost its effectiveness because it wasn’t stored properly.

Sometimes, drug names in other countries are similar or identical to drug names in the U.S., but they’re entirely different drugs. If you do purchase medicine from a Canadian pharmacy, check the ingredients to make sure you didn’t accidentally buy the wrong medicine.

Cost

Although there are risks, the cost effectiveness is reason enough for many to buy medicine from Canadian pharmacies. Brand name drugs in particular tend to be much cheaper in Canada because the government negotiates prices with the companies, while companies can charge as much as they want in the U.S.

If you buy medicine from a legitimate online Canadian pharmacy, keep in mind that there might be high shipping charges. Compare the cost of buying the drug in the U.S. with the cost of shipping from Canada. Also, remember to convert the cost of the medicine from Canadian dollars to U.S. dollars.

Everyone has different needs and priorities, so you’ll have to consider your personal situation when deciding whether or not you should fill your prescriptions in Canada. Some people don’t want to take the safety risks or break the law to save money. Others may think the risk is worth it to save a great deal of money on a prescription.