When are Duragesic Patches efficient?

I put on a Duragesic Patch on today when should I start to feel the medication to start to see in? Its 50mgc but I hear it's a powerful opiod is it true that it takes 12 hours to start to quality the meds kick within? For the 1st patch, it can take 12-24 hours for the rank of fentanyl to level stale in your system, but next will stay fairly constant for the remainder of the time you hold the patch on. And then, beside proper maintenance dosing (changing the patch every 72 hours), the even in your system will stay constant.