Estra-4,9,11-triene-3,17-dione

Estra-4,9,11-triene-3,17-dione, also known as trenbolone or 19-nor-δ9,11-testosterone, is a synthetic, anabolic-androgenic steroid (AAS) and derivative of nandrolone (19-nortestosterone). It is used in veterinary medicine to promote muscle growth and appetite in livestock.

Chemical Structure

Estra-4,9,11-triene-3,17-dione is a 19-nor compound, meaning it lacks a carbon atom at the 19th position, similar to its parent compound, nandrolone. The unique double bond at the 9th and 11th position enhances its binding affinity to androgen receptors and reduces its aromatization to estrogen.

Pharmacology

Estra-4,9,11-triene-3,17-dione binds to androgen receptors with high affinity and is transported into the nucleus of target cells where it initiates its biological actions. It promotes protein synthesis and muscle growth, and inhibits catabolism. It also has a strong binding affinity to the progesterone receptor, and can lead to side effects such as gynecomastia and water retention.

Veterinary Use

In veterinary medicine, estra-4,9,11-triene-3,17-dione is used to increase muscle mass, bone density, and appetite in livestock. It is often administered as an implant under the skin of the ear, where it slowly releases the drug over a period of months.

Side Effects

Potential side effects of estra-4,9,11-triene-3,17-dione include virilization in females, gynecomastia, water retention, and increased aggression. Long-term use can lead to cardiovascular disease, liver damage, and infertility.

Legal Status

In many countries, including the United States, estra-4,9,11-triene-3,17-dione is classified as a controlled substance. Its use in humans is prohibited by most sports organizations due to its potential for abuse and health risks.