What are scientifically proven negative effects of masturbation.
All i found was this with no citations
http://scholarlyanswers.blogspot.com/2013/01/22-harmful-effects-of-masturbation-in.html?m=1
There aren't any unless you skip out on daily events to go fap in your room.
Porn? That's another story.
friction burn
dehydration
loss of minerals like zinc
less powerful erections if constantly masturbating
cumblasts weaker and less voluminous