blood tests, before a blast, during and after a blast (look at your liver values, cholestrol, RBC, hemocrat, kidney values, immune system etc)
regular heart checks (checking for enlargement)
and consistent blood pressure monitoring
monitor these closely, they will usualy identify if anything health wise is going wrong wen on AAS
if all of the above 3 are met, and you inncur no problems (unlikely) then you can continue to blast and cruise safely