steroids are inflammatory so they actually hurt all of the above, plus they make you lift heavier which strains the body
that is why dudes hop on juice and tear their shit up fast.
i know this seems CRAZY but hear me out.
you want to increase mobility and flexibility? then work on your mobility and flexibility. stop wanting a pill to do the work for you
find a good quality yoga place and sign up, that will help.. I do yoga and i also end my workouts with stretching for 15-20 minutes. it has helped me amazingly well