Can I break an op40 oxycontin 40mg in half and will it still work?

OP 40 or OxyContin 40mg is a long acting version of oxycodone that is meant to be a slow timed release. When you split, crush, chew or alter them in any way you defeat the time release mechanism and can have too much medicine release all at once. Also when you try splitting them, the way they are made, doesnt mean that you will get 20mg in one half and 20mg in the other half. Since they are meant to be taken whole, the medicine may not be evenly distributed like a pill that can be split. Many of the overdoses that you may have heard about with OxyContin were caused by people splitting or crushing these tablets. It is very unsafe to do this and it also constitutes abuse of the medication since it is meant to be taken whole. If the medication is too strong for you to take a whole pill then you need to talk to your Dr about reducing your dose. They do make a 20mg tab.

Yes, it will work to give you an overdose. Don't break them up.