Question: how long do the positive effects of prednisone last?
Answer: You could expect a dose or prednisone to be out of your system in 16.5 to 22 hours. The elimination half life of prednisone is around 3 to 4 hours. This is the time it takes for your body to reduce the plasma levels by half. It usually takes around 5.5 half lives for a drug to be completely eliminated from your system.