Nandrolone is commonly marketed as its decanoate ester, ?deca-durabolin? and less commonly as a phenylpropionate ester, ?durabolin?. Actually, deca durabolin is a registered trademark of Organon Corporation in the United States and/or other countries. The chemical name of active ingredient in Deca Durabolin is Nandrolone Decanoate, which was commercially marketed first as a prescription medication in 1962. The United States FDA approved deca-durabolin in 1983.

Nandrolone is structurally very similar to testosterone, but it lacks a carbon atom at the 19th position. That is why it is sometimes also known as 19-nortestosterone. This structure is a steroid that exhibits much weaker androgenic properties than testosterone.

In deca-durabolin, nandrolone binds to the androgen receptor to a greater degree than testosterone, but due to its inability to act on the muscle in ways unmediated by the receptor, has less overall effect on muscle growth.

Deca-durabolin is unique drug, as unlike most anabolic steroids, it is not broken down into the more reactive DHT by the enzyme 5a-reductase, but rather into a less effective product known as Dihydronandrolone. This is the property that mitigates some of the negative effects associated with Nandrolone drugs, such as deca-durabolin.

However, some of the negative effects are associated with high doses of deca-durabolin, which include strong occurrences of oily skin, acne, body/facial hair growth and hair loss, gynaecomastia, reduced libido, erectile dysfunction, cardiovascular damage, and several ailments resulting from the drug's effect of lowering levels of luteinizing hormone through negative feedback. However, the positive effects of deca-durabolin include muscle growth, appetite stimulation and increased red blood cell production and bone density.

Several studies have proved deca-durabolin as the drug effective in treating anaemia, osteoporosis and some forms of neoplasia including breast cancer, and also as a progestin-based contraceptive. Thus, deca-durabolin is a restricted drug under the Controlled Substances Act. Yet, deca-durabolin is available by prescription in most countries that have not waged the American-style "War on Drugs" and ?anti-steroid campaigns?.