From WikiMD's Food, Medicine & Wellness Encyclopedia

19-Norandrostenedione (19-Nor-4-androstenedione or estr-4-en-3,17-dione) is a prehormone that was once popular among bodybuilders. Before its ban by the United States Food and Drug Administration (FDA) and inclusion on the World Anti-Doping Agency's list of prohibited substances, it was used to increase the body's production of the muscle-building hormone testosterone.

Chemical Structure and Function[edit | edit source]

19-Norandrostenedione is a derivative of the steroid hormone androstenedione, with the critical difference being the absence of a carbon atom at the 19th position. This slight modification significantly alters its biological activity, making it a precursor to nandrolone, a potent anabolic steroid, rather than to testosterone directly. When ingested, 19-Norandrostenedione is converted in the liver to nandrolone by the enzyme 17β-hydroxysteroid dehydrogenase. Nandrolone, like testosterone, promotes protein synthesis and muscle growth, but with reduced androgenic effects, making it appealing to bodybuilders seeking to increase muscle mass without the side effects associated with high levels of testosterone.

Legal Status and Doping[edit | edit source]

In the early 2000s, 19-Norandrostenedione was available as a dietary supplement in many countries, including the United States. However, due to concerns about its safety and its potential to enhance athletic performance artificially, it was banned by the FDA in 2006. The World Anti-Doping Agency (WADA) also prohibits its use in competitive sports as it is considered a performance-enhancing drug. Athletes found to have used or possessing 19-Norandrostenedione face sanctions including suspension from competition.

Health Risks[edit | edit source]

The use of 19-Norandrostenedione, like other anabolic steroids, carries several health risks. These include liver damage, changes in cholesterol levels, increased risk of heart disease, hormonal imbalances, and psychiatric effects such as aggression and mood swings. Its conversion to nandrolone can also lead to a positive test for steroids in athletes, leading to potential bans from competition.

Research and Clinical Use[edit | edit source]

Research on 19-Norandrostenedione has been limited due to its legal status and the ethical concerns surrounding the use of performance-enhancing drugs. However, studies on nandrolone, its active metabolite, suggest potential therapeutic applications in the treatment of muscle wasting diseases, osteoporosis, and anemia. Nonetheless, the use of 19-Norandrostenedione for these purposes is not approved, and its clinical utility remains speculative.

Conclusion[edit | edit source]

19-Norandrostenedione represents a class of substances that blur the lines between dietary supplements and performance-enhancing drugs. While it may offer short-term benefits in terms of muscle growth and athletic performance, the long-term health risks and legal implications make its use controversial and, in many jurisdictions, illegal.


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Contributors: Prab R. Tumpati, MD