When I imported my car from Canada, customs searched my car and my medicine was in a bottle in the trunk. The bottle, not the original, had a mixture of pills - vitamins, thyroid tablets, asprin, and amphetamines. I told customs that I had a prescription for the amphetamines and they advised me to keep them in their original bottle. I explained that I often put them in smaller bottles because I hate to carry large bottles (500/tablet sized). They didn't say anything else about it.

They did however try their best to hit me up for import taxes, but I explained that the car was NAFTA-exempt. They looked and looked, and with a disappointed look, they said I didn't owe any taxes.