Branched Chain Amino Acids and kidney pain

Hello All

I have found through experimentation that Branch chained amino acid supplement really help me with strength and stamina and sleep.

I am happy to have discovered this

However when I use a particular formula I experience kidney pain.

I have three questions

Why such strong kidney pain?

Does anyone else have this problem?

Does anyone here use BCAAs and if so what do you use?

I know this question is better suited to a body builder forum but I trust the opinions expressed here.