I should clarify that technically prescriptions aren’t allowed to be sent by non medical people, but there is no way they can tell and they never ask aside from whether you’re sending anything hazardous. I send edibles and weed via us mail, and as long as it’s securely packaged as to not fall apart in transit, nobody will know and I doubt they really care that much about sending one person’s prescription, as long as you’re not like trafficking huge quantities.