I think the IBF go with the local commission on drug testing so UKAD/WADA testing.

Going up and down in weight rarely works out. Brook looked a bag of shit against Jones at 147 then looked the business at 152 or whatever it was for the return. He's clearly a better fighter a shade north of 147lbs. Brook used every ounce of the weight for the Golovkin fight, he was 176lbs a month out was it? Everyone went mental. I think despite doing things properly these days, making weight is going to kill him.