Well I have had loading doses. Six for 2 weeks every other day. The tiredness went straight away. The nerve damage and mental damage will take a little longer. But I no longer take IBS tablets I don't have obsessive thoughts as much, I feel I am in control of my mind. I did start researching being mindful and found this very useful. I got PA and b12 deficiency because of my under treated thyriod. But it's complicated. Now if anyone is still suffering on their thyriod journey then it's best to get your b12 and ferritin levels checked as I had very low iron also. Being b12 deficiency is very dangerous and needs to be treated. I was clueless about it.