I decided to try l-tyrosine to address my difficulties with focusing and working efficiently while coping with chronic sleep deprivation. I have been taking it for about a month, 1000mg before breakfast and 1000mg before lunch. It helps quite a bit, and improves my mood. I can really tell the difference if I skip a day. I would caution against taking this too late in the day as it can cause insomnia (I was up until 6am after taking 1000mg at 7 pm)