I was diagnosed with Lupus and my Rheumotologist gave me a shot of B12 during my last visit. It totally wiped me out for the next 3 days. Extreme fatigue, weak, pale and just out of it. Has anyone else ever had a reaction to a B12 shot?Post Edited (Therese518) : 3/13/2023 3:28:18 PM (GMT-8)