To our knowledge there has never been an instance where anyone attempting to import medicine for personal use in a 90 day supply has ever had any legal problems. A visit to the US Customs website under Traveler Information will confirm this. Customs reserves the right to refuse any shipment entry, but this does not mean that such attempted importation is a crime unless the drug in question is illegal to possess, i.e. Marijuana, LSD, Ecstasy etc.
When medications are obtained through the mail, Customs only has two options with regards to import of prescription meds coming from a legitimate pharmacist or physician, to refuse them entry or to pass them through. Since no less than 250,000 pieces of foreign mail, including flat envelopes resembling correspondence, regular mail, documents, small packages, etc. arrive at every USA port of entry each day for clearance, it is physically impossible for them to reject or even scrutinize any more than 10%. So 90% of the time meds pass un-inspected, but legally. If a package is randomly looked at, if a customs clerk deems it inadmissible for import, the worst scenario is that the package is 'held' or what is usually called 'seized'. This seizure can be contested if the meds shipped are in a 90 day supply or less for personal medical use.

There are no legal repercussions for this type of import. It is not unlawful, and a 'seizure' is less ominous than a parking ticket. You have to 'pay' a parking ticket. A 'seizure' simply means 'Shipment refused entry'.