Hi there, butrans 20mg patch 1 a week for the past 10 months. i was wondering how long it takes to come out your system completely. ty?

Potentially a month: or even more. Buprenorphine is a very long-acting drug, and its major metabolite is also very long-acting. It is bound to serum proteins and both the parent drug and its metabolites can be detected for weeks after chronic use. Eventually only the metabolites are detected, but depending on the sensitivity of the method used for testing, it can be detected for more than a month out.