You do not need a permit to leave with most prescription medicines even if they contain a controlled substance, so long as:
- you are departing Australia as a passenger on board a ship or aircraft
- the medicine is carried in your accompanied baggage
- you carry a letter or copy of your prescription (written in English) from your medical practitioner to certify that the medicine has been prescribed to you to treat a medical condition
- the quantity of the medicine does not exceed three months' supply.
Special rules apply when travelling overseas with PBS subsidised medicines
For quantities exceeding the 3 month limit, you will require a permit from the Therapeutic Goods Administration to export your medications.
Different countries have different controls on drugs and medicines so you should contact the embassy or consulate of your destination country to find out if you need permission to bring your medicine with you. You will need to find out about countries that you might be entering as a stop-over, as well as your final destination. The Department of Foreign Affairs and Trade have a list of embassies and consulates.