Like other AAS, boldenone is an agonist of the androgen receptor (AR).  The activity of boldenone is mainly anabolic , with a low androgenic potency. Boldenone will increase nitrogen retention, protein synthesis, increases appetite and stimulates the release of erythropoietin in the kidneys.  Boldenone was synthesized in an attempt to create a long-acting injectable metandienone , for androgen deficiency disorders. Boldenone acts similar to metandienone with fewer adverse androgenic effects. [ medical citation needed ] Although commonly compared to nandrolone , boldenone lacks progesterone receptor interaction and associated progestogenic side effects.
Some bodybuilders and athletes use trenbolone esters for their muscle-building and otherwise performance-enhancing effects.  Such use is illegal in the United States and many other countries. The DEA classifies trenbolone and its esters as Schedule III controlled substances under the Controlled Substances Act .  Trenbolone is classified as a Schedule 4 drug in Canada  and a class C drug with no penalty for personal use or possession in the United Kingdom .  Use or possession of steroids without a prescription is a crime in Australia .