Personal use generally means no more than a 90-day supply. You should think twice before bringing in quantities larger than that, because if authorities suspect you have commercial intentions, you could land in legal jeopardy -- and lose the drugs.
People familiar with the practice say you generally can pass through customs without much hassle if you have no more than three months' worth of a medication, you declare it to customs agents and you show them a doctor's prescription or a personal note attesting it is for personal use, along with contact information for your physician.
Even in the worst-case scenario, an unsympathetic agent might confiscate the drugs -- but not arrest you.
Ordering drugs online from foreign pharmacies also tends to go largely unchallenged. Legally, the FDA can refuse entry of the package at an international mail facility. "That does happen from time to time," but not often, says Levitt.
It is more common for shipments that do get through to be detained for several days pending FDA inspection. So, if you need to take your medication every day, be sure to build in a sufficient margin for potential delays.
A far bigger risk if you're shopping abroad for medications is that you might not get what you paid for -- and it might not be safe. "There's a lot of junk in the pharmaceutical world," says Dr. Ken Croen, a primary care physician at the Scarsdale Medical Group in Westchester County, N.Y., who advises many of his patients on how to buy drugs safely in Canada.
And there are plenty of rogue operators, especially in the world of online pharmacies. You will need to do a little vetting.
Before doing business with an online pharmacy, confirm it is licensed in its country of origin and that the country has strong pharmacy regulations, says Dr. Aaron S. Kesselheim, a professor of medicine at Brigham & Women's Hospital and Harvard Medical School. (Read below for websites that can help with that.)
Countries with well-regulated pharmacies include Canada, New Zealand, Australia, much of Western Europe and Turkey.
Also, check to make sure the pharmacy posts an address and phone number on its website. Experts advise against using online pharmacies that don't require a doctor's prescription: They are more likely to cut other corners, as well.