Mesterolone has within our sport many purposes and its use and effect is debated and dicussed in many threads. What lots of bodybuilders don't realise is that the usage of all means is dependant, let me explain.
When you use a gram of testosterone you have a big chance that it will convert to a more aggressive and harsher compound, namely DHT. You most likely use un anti-estrogen like Arimidex.
When on the other hand you use a gram of nandrolone, this will convert into a milder compound (DHN) by the same enzym (5-alpha-reductase). Use of Arimidex etc is useless and you should use Nolvadex and…proviron to prevent the side-effect we call in slang “deca-dick” which is a loss in libido.
Also hotly debated is Provirons use in PCT-HRT-bridging. PCT (post cycle therapy) is meant to avoid a crash after you stop using steroids.
Bridging is the use of certain means some bodybuilders take between 2 cycles.