Interesting. I make up my own electrolyte solution, however this seems to be more about amino acids than salts?
I found the Scivation Xtend on Amazon:
“Ingredients:
L-Leucine (3.5g), L-Glutamine (2.5g), L-Isoleucine (1.75g), L-Valine (1.75g), L-Citrulline DL-Malate (1g), Flavours, Acidity...