Ive used it a few times and will use it again. When you start training you dont want to stop and your recovery between sets becomes lower. Its strange but i felt like throwing weights around the gym at some points cos you can lift so much more. I was curling bigger dumb bells than some really big guys and one guy even asked if was on steds. The problem is when you come off it after 5-6 weeks you feel lame. All the extra strenght goes and it becomes harder for you drag yourself down the gym. My mate used it too and seen little improvements, its down to the person and everyone will be different. Well worth a try tho, its fookin awesome when you collect weights from the shelf below where you used to go and people are thinkin no, he aint gonna lift that... Then you shift 3 sets of 8...