Does all medication need labels?

If Im going on a domestic cruise - do I need to get labels on things like Panadol and Sea-Sickness tablets?

No. I just take them in their original packaging. Prescription meds should have the chemist label on them. I also take a letter from my doctor stating my prescriptions and conditions just in case (I take one that is on the restricted list and also carry needles) but I've never been asked for anything. Even international, when I fill our the declaration card, I tick 'yes' to carrying in medications and the officer asks if they are prescriptions and if I'm carrying less than 3 months worth - I answer yes and have never been asked for them to see what I've got or any proof (perhaps I look honest?). Over the counter stuff just keep in identifying packages, either the original boxes or the plastic strip that clearly says Panadol etc on the back.