Sorry to rain on your parade but if your name isn't on the prescription, and you can't demonstrate that it is a reasonable amount of the drug for your own medication during your visit, save your money and leave the drugs at home.
Same goes with freight. It's a controlled substance or it wouldn't be perscription. You have to have a license to ship those and the recipient has to have one as well as I understand it.
Either act could land you in jail as like it or not, you are technically smuggling drugs.
HM Revenue and Customs
Most if not all countries have such rules. Some with rather drastic penalties.