The only problem i have with trying to stay lean and gain mass is you will be limiting your progress by not eating enough calories to support maximun gains.Ideally you should gain a little weight as you progress in the cycle,not a lot of weight but a pound or two a week.I always like to diet down before i start a cycle so i can eat enough to support new muscle. I find it difficult to train 100% while dieting and i have a high metabolism.Spend a year training for more mass and dont worry about being lean,you will get to your goal faster.You have to eat big to get big..........within reason. Masteron effects every mans prostrate,some more than others.I never had an issue with hair loss untill i used masteron,never had prostrtate issues like enlargement or pissing problem but got prostrate cancer last year and was treated for it with androgen depravation thearpy for 6 months ( no test in my system while doing treatments). Masteron is great for being hard and lean but i think it should be limited to contest prep and for a short period of time.Probably not a problem for younger guys but should be used carefully in older guys,on my visit next week to my urologist i am going to ask him what his youngest prostrate cancer patient was. I thought high levels of testosterone would increase your chance of P cancer but a doc on another forum says he thinks the prostrate saturates with androgen easily and didnt think high levels of test would make a difference,if you think about it its the older guys that get the cancer and their levels of test are actually low,so the doc might be right about the amount of test not making any difference.....