Chemically 19-norandrostendione is simply an androstenedione molecule without any carbon at the 19th position.  Although this isn't the most abundant adrenal androgen in the body, we can find trace amounts in human placenta and the testicles of horses and bulls. If, years ago, you tried using those glandular orchic extracts, you were getting very small amounts of norandrostenedione.

The interesting thing about nor-androstenedione is that the dehydrogenase enzyme in the liver won't add any carbon at the 19th position. It adds only a hydrogen at the 17th position.  So, without any carbon added, the nor-andorstenedione won't be converted to testosterone.  It's converted to nor-testestosterone instead.  In basic terms: norandrostenedione is converted to nandorlone in the liver.  This same conversion happens in the placenta, which is exactly why a female athlete who is pregnant or who's even had a recent abortion will generate a positive on the steroid test for nandrolone.

Nandrolone, on the plus side, has a high affinity to steroid receptors.  That means once it latches onto a steroid receptor, it lingers longer than testosterone would. Nandrolones have been chosen over testosterone for two reasons: nandrolones don't have much conversion into estrogenic compounds, and the androgenic, non-anabolic side effects like acne, body-hair growth/head-hair loss are not as prevalent with the nandrolones.

Norandrostenedione stacks well with Androstenedione because it mirrors the anabolic and androgenic effects of the ever popular Deca-Durabolin and Injectable Testosterone combination. Further testosterone enhancements could be realized with the addition of Tribulus Terrestris, as this natural product from Bulgaria increases the bodies LH (Leutinizing Hormone).  There is actually a new supplement from MuscleTech that has a combination that is similar with DHEA, Androstene, and Tribulus terrestris in it.  I can not vouch for this supplement (by MuscleTech), I just wanted you to be aware of it.