Despite appearances, this theory has very little evidence to back itself up with no real scientific evidence to suggest that a bridge is even possible, although granted that the majority of our working knowledge comes through trial and error. However, even the propnents of a "d-bol bridge" admit that complete restoration of LH function will not be achieved until one is completely off of all compounds. With that said, it is unlikely that a "bridge" will help to maintain muscle mass while you are able to recover both HPTA and LH function. The only solution is to come completely off all substances and run a proper post-cycle therapy.
Gone are the days where you could go to a doctor and get a script to buy steroids from a pharmacy, due to steroids being abused by athletes and bodybuilders they are now illegal. The only way to buy steroids now is on the black market, either from a dealer or from an online source. When steroids were legal and were purchased from a pharmacy, the only steroids you could get were pharmaceutical grade which were extremely high quality and worked far better than the “underground” stuff. Today pharmaceutical steroids are harder to get hold of and cost a lot more, for this reason many people opt for black market steroids which usually are lower quality and can cause infections due to them being produced in an non-sterile environment. Only injectable steroids need to cause concern when purchased from an underground lab, oral steroids don’t need to be produced in a sterile environment.