Switching from a brand name to a generic drug is an oft-touted way to save money on prescriptions. But poor manufacturing processes and lax regulations may put you at risk.

The vast majority of prescription drugs sold in the U.S. (86 percent) are generic. Often, patients don’t have a choice.

But in countries like India, Taiwan, and China, large companies farm out their contracts to small operations that may be making drugs over coal-fired stoves in unsanitary conditions.

The result is that no one knows what kind of impurities are getting into these drugs or what kinds of fillers are being used. You also need to beware of counterfeit drugs from England, Canada, and elsewhere.

If you buy drugs online, here are some tips to ensure the medications you buy are genuine:

• Make sure the site requires a prescription and a pharmacist is available to answer questions.

• Buy only from licensed pharmacies within the U.S.

• Don’t provide personal information such as credit card numbers unless you are certain the site will protect them.

And beware of sites that do the following:

• Allow you to buy drugs without a doctor’s prescription

• Offer deep discounts or prices that seem too good to be true

• Send spam or unsolicited emails offering drug deals

• Are located outside the U.S.

• Are not licensed in the U.S.