If I go more than 24 hours between tablets I crash. I have been on these for a few months, maybe a year and a bit, not sure but they are not doing me any good if I have to be so rigid in when I take them. It just isn't practical. I feel so down at the moment. I am struggling with being a mum, I am getting over two bad asthma attacks, have no family and just need something to give me back me.