I found this article interesting...which seems to be in line with what you're saying. I don't agree with it but it does substantiate what you're saying.
http://www.mindandmuscle.net/content/page-84.html
Hepatoxicty: Fact or Fiction
by Roy Harper
We all know that the alpha alkylated steroids are hepatotoxic, right….. But, is there actually any truth to this? We’ve been told for years that if you take 17 alpha-alkylated steroids, you will eventually run into liver problems. Never combine 17 aa’s, never go beyond 50mg day, never go longer than 4 weeks, etc. All of this is crap! As I we walk you through some studies, today, you’ll see 17 alpha-alkylated steroids can be hepatotoxic but not to the degree you would think.
To make a steroid hepatotoxic, you need only a small change to a steroid molecule; A strong bond that cannot readily be down broken by enzymes in the liver. This may be a bond at the 17th position, or even at the 1st position (as in methenolone or proviron). Because the liver cannot easily break the steroid down before it is released in to the blood stream, this also results in the steroid to becoming more orally bio-available.
We can see that the liver has to work harder to break down these steroids. Enzymes in the blood and tissue easily metabolize other steroids such as Testosterone. Commonly, this increase in liver activity has been viewed as a harmful process, but as you will see, this increase is, in and of itself, irrelevant. The liver is THE filter of the human body -- it can figure out what to do with just about anything. The only real problem comes in when one keeps their liver at full blast for long periods of time.