8 is not a magic number. but it's a good reference point in a cycle to either get your blood levels checked or start to come off. with their 17a alkylation orals are obviously harder on the liver than injectables. that's not a myth. while some people run it much longer for whatever reason, your best results to side effects ratio is seen within the 6-8 week area with orals.
and in reference to halo, i don't know what the medical dosage is intended for those actually using it for the prescribed reason, but i HIGHLY doubt it's the same dosage the bber uses it for for size gains. almost never does science conduct experiments with the same dosages that bodybuilding uses. this makes many studies moot in regards to it's information to the bodybuilder.