So after reading a comment on here which I cannot find 🤦🏼‍♀️, I just wanted to say an enourmous THANK YOU to whoever suggested B12 injections! After booking a blood test, I am deficient in pretty much everything 😂 and am now on a course of B12 injections. For anyone experiencing ridiculous fatigue whilst having Tysabri, I can't recommend a blood test at your doctors enough, just in case 🤞🤞. Thank you again!