The best, I tried if for a very short time and improved both the physical performance and mental. After 2 weeks of intake, I already had significantly better memory and concentration. Unfortunately I have an irritation on the neck which is why I had weakness in one hand and tingling so I stopped using it and yet I stayed healthy. 

Currently I train Crossfit, I took it for strength and endurance along with Cardarine. It works very well, meaning definitely increased the capacity of my muscles and the weight I could lift. Also my recovery was very fast. What amazes me is that in all these intensive workouts i’ve been doing, I’ve gained a little muscle mass but taking into account that everything is super intense and yet my calories have not been that much. Very unexpected.