I commend you for working on your diet. That is by far the most important part of training and reaching your goals. My advice would be to stick to that and see where you get. I know you may not like that, but it's the truth. Doing juice at a young age (18-25) may very well damage your natural test and will put you on trt by your thirties. I'm just want you to know and contemplate that.
As far as your Mast question, I have chosen not to answer. I will direct you to the search function on top (magnifying glass). There are tons of articles here on this exact subject. Again, I wish you the very best of luck and hope you have a long and healthy lifting career.