I am definitely curious, I have never had urine that dark before, but I stay very hydrated.
Are you drinking enough water?
Also, I can't imagine it would be the aminos, the beauty of aminos is that they bypass the gut and get straight into the bloodstream. I would think your aminos are being used regardless and not being passed as waste.
James 1:16-17 ESV
Do not be deceived, my beloved brothers. Every good gift and every perfect gift is from above, coming down from the Father of lights
With God's help...Mens sana in corpore sano