A month ago I found out that my b12 level was very low at just 109. I was experiencing extreme weakness. I had also lost 5 kgs weight in 2 months. My doctor prescribed me an injection course for a month. I took 5 injections daily then 5 on alternate days, then weekly injections. I will get the last injection this week. Though I do see an improvement and I'm no longer very weak I do get tired very easily still. I have not lost any additional weight but I have also not put on any weight that I'd lost. I was expecting to return back to normal by the end of the course. I've been told to take oral supplements after the last injection. How long does it typically take for fatigue to disappear once you have completed the injection course?