What is everybodys facination with high mg/mL? The higher you go, the more it will hurt. Also, the slow dispersion of the oil in the muscle is what gives you the slower release you are looking for to maintain constant blood levels. The oil at 600mg/ML will disperse quickly, leaving a knot of test which may or may not crystalize, causing some nice pain, or else it will all be absorbed too quickly IMO.