Just read this article by:Peter "Big Cat" Van Mol
Vitamin E and Prohormones
Vitamin E is a popular anti-oxidant amongst athletes and justly so. I myself supplement 400 IU most of the year. But when on a prohormones stack it may be wise to give it a rest for a couple of weeks. As a fat-soluble vitamin your storages are plentiful if you supplement year-round. But Vitamin E will inhibit the effect of prohormones, and even some test boosters. The conversion will not happen fully, and that's only if the prohormones actually reach receptors. You are potentially cutting your gains by 50 to 60 percent. Prohormones stack well with most supplements though. Just kick back the vitamin E, you'll be getting small amounts in your multi anyway.
REFERENCE:http://www.bodybuilding.com/fun/catavoid.htm