Boldenone Undecylenate (Veterinary Equipoise)
The veterinary Equipoise product is boldenone undecylenate formulated for horses, and it is the single most-diverted veterinary anabolic in bodybuilding. Approved to improve appetite, weight and coat in debilitated horses, its long-ester boldenone gives slow, steady lean gains that made it a staple of illicit human cycles.
01 Overview
Boldenone undecylenate was developed as a long-acting injectable for equine use (Equipoise, Boldebal-H), where it improves body condition and appetite in horses recovering from illness. The undecylenate ester extends its action so that a single injection lasts weeks.
This veterinary product, rather than any human pharmaceutical, is the origin of boldenone's PED reputation. Diverted to humans it produces slow, relatively lean mass gains with moderate aromatisation and marked appetite stimulation. This entry addresses the equine product and its diversion specifically; users face counterfeit and sterility risks alongside the standard boldenone side-effect profile.
02 Mechanism
Boldenone is a moderately anabolic, mildly androgenic androgen-receptor agonist derived from testosterone by a 1,2 double bond; the undecylenate ester provides sustained release. It aromatises at roughly half the rate of testosterone.
03 Dosing
| Tier | Dose | Route | Notes |
|---|---|---|---|
| Diverted human use (anecdotal) | 300–600 mg/wk | IM | Illicit human dosing; the approved use is equine only |
Ester comparison
| Ester | Half-life | Injection freq. | Testosterone by mass |
|---|
04 Effects
| Effect | Magnitude | Evidence | |
|---|---|---|---|
| Slow lean mass gainProduces gradual, relatively dry gains over 12+ week cycles when diverted to humans. | Moderate over long cycles | Observational | |
| Appetite stimulationNotable appetite increase, mirroring its approved equine indication for improving body condition. | Observational |
05 Side effects
| Effect | Severity | Frequency | Evidence | Countermeasures |
|---|---|---|---|---|
| Estrogenic effectsAromatisation can cause gynecomastia and water retention, though less than testosterone. | Moderate | Dose-dependent | Observational | |
| HPTA suppressionSuppresses endogenous testosterone; long ester prolongs recovery time. | Severe | Universal at PED doses | Observational |