Mast can be used with anything but you have to understand the purpose of the compound and how it stacks. It’s a DHT designed for cutting, hardening and vascularity. So on paper it doesnt make sense to run it with a steroid that is designed for building mass, water retention and strength. The only acceptable reason to run Mast, IMO, is that it has been shown to be anti-estrigenic and doesn’t aromatise so it could help to lower the conversion of test and nandrolone to a minimum and as a side to that could help with any erectile dysfunctions.