Australian slang for Dexamphetamine tablets prescribed to people with ADHD but taken for their energetic, confident and euphoric effects. Typically taken in 5mg tablets, either snorted or swallowed. Snorting has a stronger instant effect and lasts around 4 hours, whereas swallowing has a longer come-up and typically lasts 6-8 hours.
"what've you taken tonight?"
"just railed a few decos and had half a bottle of gin hey"