Rose I hope you are still checking in on this post. I only had one shot of b12 a little over a week ago. I did not ask the dr. what type of b12 it was or the dose. I have an appiontment next thursday for another shot I will ask him then. Since that shot I have also been taking the sub. methly b12, at least 3000mcg a day somtimes 2 X's a day. I am not as tired but my legs, from the knee down, are killing me. In the morning they start to tingle and then form 3:00 on they are so sore and tight feeling, they just realy hurt. Also yesterday I had the starngest thing happen. I got a pain in my lower stomach and I had to urinate every 5 minutes. The only thing I drank was 1 cup of coffee and a bottle of water. (usually I drink much more) The strangest thing was when I went to the bathroom every time it was clear, like water. The pain was very bad and lasted 2-3 hours. Today I had a little pain in the morning and as the day went on everything went back to normal. I have read that you may feel worse as your body starts to heal it's self. I never expect to feel this soreness in my legs. It is very difficult to work. I was off for the whole summer. I started back to work on sept 4th. I haven't worked a full day yet. Right now the way my legs feel I don't know if I can. Iam just shocked to feel this bad. I thought I would at least feel better first and then feel a little different as my body healed itself.