exactly, when you change up a compound, even the slightest change, it effects how it will act.
rodja gave the bold, and dbol, but to add onto that, take dbol, and oral turinabol
only diff is the addition of a 4-chloro group.
as another put it, methyl test has been around for along time.
also, fyi, most underground labs sub methyl test for their orals like dbol, it's very common.
so if you've bough dbol from an ug lab, chances are, you've taken methyl testosterone and not even known it. ha ha ha funny.