I can say from my own experience that this is quite problematic. The fact is that a high-quality set of muscle mass is impossible without a well-thought-out and well-planned diet, training regimen and schedule. Personally, I don't always have the opportunity to eat exceptionally healthy. On the advice of the guys from the gym, I bought myself an injectable steroid Oxymetholone
https://steroidssp.com/t/injections-...-oxymetholone/ , which very pleasantly surprised me with its effect. He helped me build good muscle volume in a month.