Honestly to get the best out of it I recommend 4-5 days since bup has a much higher affinity for opiate receptors. What I did was switch to poppy seed tea for those four days then did my Fent as Fent has a higher binding affinity than morphine and the bup has alenough time to be cleared out of you’re system. You gotta wait a few days because buprenorphine has such a long half life.and then switch back to the tea for a 3-4 days because if you take bup right after it can send you into withdrawal with its higher binding affinity and only a partial opiate agonist