Usually the elegance of the prohormones is that some of them, specifically DHEA and androstenedione, have virtually no anabolic activity until they are converted. Overdosing, which would usually cause side effects, doesn’t happen because there is only so much 17HD available. However, 4-AD is different in two very important aspects: the enzyme needed for the conversion to testosterone is the more plentiful and efficient 3HD enzyme. More 4-AD will be converted to testosterone than in equal amounts of androstenedione in the body. But since we’d be using two different enzymes, you could “stack” the two together for an additive testosterone boost. The other significant benefit is that 4-AD is, in its unconverted state, highly active, perhaps greater than testosterone.

Although touted as being the most anabolic of all the prohormones, its promoters tend to ignore or downplay the negative aspects of 4-AD: it has significant masculizing effects. It imparts androgen characteristics: oily skin, acne, body hair growth, scalp hair fallout. So this variant would be entirely unsuitable to women, and many men also.

Knowing about its androgenic side effects, Pat Arnold developed a nor-variant of the 4-AD, which he has trade named Nor-Androdiol. This is in actuality, an elegant prohormone. It has all the attributes of nandrolone (as Nor-4-AD converts to nandrolone), but uses the superior and efficient 3-HD enzyme, so the conversion to nandrolone is greater than the nor-androstenedione to nandrolone conversion. And because each prohormone has different enzyme pathways, there would be an additive effect in stacking the two together. Another safety factor built into Nor-Androdiol is that the prohormone in its unconverted state isn’t active like the androgenic 4-AD is. So overdosage and side effects cannot happen with Nor-Androdiol, which can’t be said about 4-AD.