All Anabolic Steroids put stress on the liver. So does alcohol, prescription drugs, and asprin. This is the reasoning behind bodybuilding veterans not recommending “oral only cycles”. Oral steroids are methylated in order to bypass breakdown by the liver. As a result they are highly toxic to the liver.

The reason why injectable steroids are recommended by mainstream bodybuilders to be the base of a steroid cycle is because it is much easier on the liver. Injectable steroids are not methylated and they slowly release over days putting much less stress on the liver.

If you want an equivalent anabolic effect of a oral steroid as you get with injectables you will be putting your liver under a lot more stress. The liver is a very resilient organ and can even grow back if it’s severed or damaged. However, there is no reason to put your liver under undue stress by using mainly orals.

Recommended liver supplements on cycle

Milk thistle is a general liver health supplement. NAC seems to be even more important in helping against liver detoxification and healing. Keep in mind that liver supplements (in theory) should reduce the potency of your steroids. Many bodybuilders for this reason do not take them during their cycle. I think it’s a good idea to use low doses of NAC and milk thistle even while on cycle. Frequent steroid users should use liver health supplements everyday year around.