I'll be visiting AKL and PER for a vacation (from the USA).
This Australian government website says (bolding mine)
What should I do when I arrive in Australia with medicines for personal use?
* Comply with all requirements of the Australian Customs Service in relation to declaring medicines you are bringing into Australia.
* For all medicines that you are carrying, ensure that you have a prescription or written authorisation, showing that the medicine is for treatment of your medical condition.
* For medicines containing a substance requiring a permission from the Office of Chemical Safety (for example anabolic/androgenic steroids) or the Therapeutic Goods Administration, produce your permit permitting you to bring the medicine into Australia.
* For any medicine subject to quarantine requirements, show your import permit to bring the product into Australia.
* Retain the documents relating to your medicines throughout your visit and have them available to present again at departure on request by Customs or Quarantine officers.
* Further information about importing medicines for personal use may be found on the Therapeutic Goods Administration website.
Do I have to revisit my doctor to get a letter, or revisit my pharmacist to get a copy of the original prescription, or will the pharmacy's label on the box of pills suffice?