As of 2015, if both the pharmacy and the patient are within the United States, the law only prohibits refills for some of the drugs classed as controlled substances, reports the U.S. Department of Justice Office of Diversion Control. It is not legal to import prescription drugs from other countries.
Internet refills are legal for Schedule III, IV and V controlled substances, states the Office of Diversion Control. These include potentially addictive drugs with lesser potential for abuse, such as ketamine, anabolic steroids, Valium, Xanax and cough syrups with low doses of codeine.
While not technically legal, U.S. law enforcement generally turns a blind eye to drugs purchased from other countries in person or online as long as the drugs are legally prescribed and for the patient's personal use, says WebMD. However, it is unwise to seek to import any drug classed as a controlled substance.