Tattoos --- 4,000mg of tylenol/apap/acetaminophen is the highest daily (24 hr) amount.
Re side effect vs liver -- the way my doc explained it, the literature uses the phrase side effect but the itching is actually caused by the liver being taxed. With gender, body mass, physiological differences, one person's liver being taxed might be someone else' "ok".
I had elevated liver enzymes after rarely exceeding the 4K mg daily acetaminaphen, which is why I asked on a different thread if other people,who daily exceeded 4k ever had any liver problems. I had all the side effects - itching, bruising (we thought I had leukemia!), shallow breathing (thought asthma), etc!
Well if anything, the itching got my wife to buy Dove soap for me and I'm the manliest guy with the softest skin now!