I have tried supplementing with the amino acid in the past. I have tried with 50 100 200 and 400mg The best dose for me was 200mg It makes me very sleepy and it

I have tried supplementing with the amino acid in the past. I have tried with 50 100 200 and 400mg The best dose for me was 200mg It makes me very sleepy and it does not help with concentration. I tried to combine it with caffeine but the result was not good. For concentration, coffee is the best for me. For sleeping I use melatonin but only if I pull a long night