Equipoise (Boldenone Undecylenate)

Only for animals. In the USA it is approved as an injection for horses, as an aid for debilitated horses when weight, hair coat or general condition should improve. Horses intended for human consumption must not receive it. There is no approval for humans and no trial on ClinicalTrials.gov (as of 25 October 2026).⁹¹⁰

This has not been measured in humans. In horses the half-life after an intramuscular injection had a median of 123 hours and absorption from the depot 8.5 hours. The long undecylenate ester makes the compound leave the oil slowly.⁵

In a rat study the liver markers ALT rose by 192 and AST by 100 percent after 8 weeks, urea and creatinine roughly doubled. LDL rose by 140 percent, HDL fell by 41 percent. Under the microscope liver and kidneys showed tissue damage. A second rat study found more LDL, less HDL and a heavier heart relative to body weight.¹³

In rats LH, FSH and testosterone inside the testes fell after 8 weeks. Only 60 instead of 87 percent of sperm were motile, 41 instead of 17 percent were misshapen. In rabbits the share of the testes in body weight fell. Reviews of anabolic steroids describe that natural hormone production can stay disturbed for months after stopping.²⁴⁸

A review of anabolic steroids describes that they can stimulate erythropoietin and red cell production and affect haemoglobin. There are no controlled human data on this for boldenone specifically. That is why the entry advises having haematocrit checked regularly.⁸

In a doping research study men received oral boldenone. Their urine contained boldenone itself and nine breakdown products, more than 95 percent of them as stable conjugates. Doping control uses this pattern as evidence.⁶