I believe tren causes this the worst, every guy I've seen who runs tren has hair all over their shoulders and back, especially on the delts, you'll just have to shave it.
the best i can recommend is to either wax it or shave it more often... otherwise, im not sure what to say other than its just part of this bro... i wish i had some magic remedy but i dont and its not likely there will be one...
There's not a lot you can do about it, and a lot of that depends on genetics and the individual. Of course gear can accelerate it, but not everyone gets extra hair growth on gear. I really haven't noticed it affecting anything myself.
Just shave as needed
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