I know a couple of guys besides myself who are on, most of the time.
I have been on at least 10 months, just “bridging” until my current test/Fina cycle ends which will be in about 40 days.
Gyno can be managed, but needs to be watched/managed and you need to use anti-E’s, but those cause sides too,
So……………..
The biggest negative side affect, is actually injury,
Your tendons, ligaments, joints, and soft tissue connectors just don’t grow or keep up with your muscle and strength growth. It is easy to over do it and then you have to try and recover from an injury, that you are just guessing at some times. You don’t know how you did it, or what you did, you just know something hurts and is preventing you from doing something you normally do in the gym.
Plus every stupid injury involves time off from the gym.
For instance, I hurt my back last week, Is it a muscle, a disc, a nerve ending, I don’t know, but on back day, I can’t bend over at the waist.
I was using the word bridging sarcastically if you did not catch it.
Also this sport we are involved in, is very addictive, psychologically.