Apply whatever standard you like. From clinical observation to triple blind peer reviewed high powered studies involving tens of thousands.
Most AAS and other BB compounds are used on the basis of feels, their bro science observations, and at best, a working hypothesis as to their mechanism of action.
There are enough well established positives, like improved insulin sensitivity, and millions of patient years demonstrating a far better safety profile than just about anything BBs inject, that even a minor benefit on balance makes a weekly dose a net positive, imo.
The growing mountain of much less well established, but still evidence based, hypothesis developed over the last 30 years are just the icing on the cake if even 2% of are unequivocally established.