This gets cited here weekly, usually second-hand, so it is worth setting out what it does and does not establish.
The variables that decide how a cross-border order goes are declaration wording, the destination country's import rules for prescription medicines, and whether the shipment looks commercial. Personal-import allowances exist in some jurisdictions and not in others, and where they exist they are usually conditional on a prescription and a quantity limit. The failure mode is normally a seizure notice rather than anything worse, and a reshipment policy is the thing worth confirming before ordering rather than after.
Where I think it is weakest: the follow-up is short relative to how long people actually take these drugs, so durability is an assumption here rather than a finding.
What would genuinely help is knowing which of the variables in a cross-border order actually determine the outcome, and which are superstition. If the honest answer is that nobody knows, that is a useful answer and I would rather have it.
Note on sourcing:
Figures above are from the primary publication rather than the press summary. If a number here disagrees with one you have, post yours and we will work out which of us is reading a secondary source.