A medical device comprises a medical monitoring or treatment device configured to provide a monitoring or treatment operation on a user, the medical monitoring or treatment device operable with an insertion needle (5635； 5735)； and a pierceable membrane (5640； 5740) containing an agent (5650； 5750), the pierceable membrane (5640； 5740) positioned to be pierced by the insertion needle (5635； 5735) during operation of the medical monitoring or treatment device and to allow the insertion needle to cause some of the agent to be carried from the pierceable membrane (5640； 5740) to the user.
