library.onepin.app/equipoise-boldenone-undecylenate Peptide Education Library
Education only, not medical advice 21+ Every dose is an example to finalize with a licensed provider
Hormonal Anabolic-Androgenic SteroidNot FDA-approved · research compoundControlled substance

Equipoise (Boldenone Undecylenate)

Boldenone Undecylenate · EQ

300-400mg/week – 300-600 mg IM 1x weekly (sometimes split 2x)
InjectableTestosterone DerivativeMildly AromatizableLong-Ester

Boldenone undecylenate, marketed as Equipoise (EQ), is a long-ester injectable anabolic-androgenic steroid originally developed for veterinary use - most commonly in horses for improving appetite, weight gain, and physical condition. It is a testosterone derivative with a double bond between carbons 1 and 2 (similar modification to methandrostenolone / Dianabol), which shifts its activity toward anabolic with reduced androgenicity. The undecylenate ester is very long, giving it a plasma half-life of approximately 14 days and supporting once-weekly injections.

Quick Start
Route
IM (intramuscular)
Start low
300-400mg/week IM
Frequency
1x weekly (sometimes split 2x)
Timing
No fasting required

Once-weekly injection is sufficient due to the very long ester. Many users split into 2 injections/week simply for smoother blood levels. Plan cycles 14-20 weeks - full effect takes 4-6 weeks to appear. Monitor hematocrit (CBC) at weeks 6 and 12.

Start here. Every protocol below is ordered lowest-first. Begin at the smallest effective dose, hold about a week to assess tolerance, and step up only if needed.

Tiered Protocols · lowest first
Conservative start
300-400mg/week · IM (intramuscular) · 1x weekly (sometimes split 2x)
conservative starter
300-400mg/week
1x weekly (sometimes split 2x)
Expert
Lean Tissue & Endurance Phase
300-600 mg · IM · Weekly
anecdotal · community
VETERINARY COMPOUND - NO HUMAN APPROVAL, NO HUMAN TRIALS. FDA-approved for horses only at 0.5 mg/lb IM, repeatable after 3 weeks; the label states "do not administer to horses intended for human consumption". There is not one registered human study. Every human dose in circulation originates from bodybuilding forums.
300-600 mg
Weekly
01

How it works

Boldenone binds the androgen receptor (AR) with moderate affinity and drives protein synthesis and nitrogen retention. The 1,2-double bond reduces androgenicity relative to testosterone while preserving strong anabolic activity - anabolic-to-androgenic ratio roughly 100:50.

Boldenone aromatizes to estrogen at approximately half the rate of testosterone. This is lower aromatization than methandrostenolone (which converts to methylestradiol) because boldenone converts to normal estradiol at a reduced rate rather than to a more potent estrogen. Estrogen control is usually needed only when EQ is run alongside a testosterone base at meaningful doses.

A distinctive feature is pronounced stimulation of red blood cell production (erythropoiesis) - often more than other AAS per unit dose. This improves endurance and vascularity but also raises hematocrit significantly, requiring periodic blood donation or CBC monitoring to prevent polycythemia.

The undecylenate ester is among the longest in use, with plasma half-life ~14 days. Steady-state takes 4-6 weeks to reach, so cycles must be long (14-20 weeks) for full effect.

02

What to expect

Early
Days 1–7

First 4 weeks: minimal visible effect. Appetite may begin to increase. Most users mistake this for a 'dud' cycle - EQ needs patience.

Mid
Weeks 2–4

Weeks 5-10: steady lean mass gains, vascularity increase from erythropoiesis, improved endurance. Hematocrit check at week 6.

Later
Weeks 4–12

Weeks 10-20: peak benefit. Sustained lean mass, high vascularity. Blood work (hematocrit, lipids, blood pressure) essential. Many users donate blood mid-cycle to manage polycythemia risk.

03

Evidence

HumanPresent
AnimalPresent
In-vitroPresent

References for this compound are being re-checked against their source records. We are not showing them until each one is confirmed to support the claim it sits under.

04

Side effects & safety

Commonly reported

  • Significant hematocrit rise (polycythemia risk)
  • Appetite increase (often substantial)
  • Mild aromatization - some estrogenic effects possible without AI
  • Suppression of endogenous testosterone
  • Lipid shift (HDL drop, LDL rise - milder than orals)

Less common & notes

  • Elevated blood pressure (partly from hematocrit rise), oily skin, acne, hair loss in genetically predisposed users, mood changes.
  • Rare but serious: thromboembolic events from severe polycythemia (stroke, DVT, PE) - hematocrit must be monitored.
  • Women: virilization risk; used rarely in women and only at low doses.
05

Pharmacokinetics

Illustrative plasma concentration · 62 d
Half-life
~14 days
Peak · Tmax
5-7 days

Post-injection

Elimination
5-6 weeks

Detectable up to 18 months in anti-doping tests due to long ester

Bioavailability
~100%

IM (oil depot)

Duration of action
10-14 days

Per injection - supports 1x weekly or split 2x weekly dosing

Clearance

Hepatic metabolism. Renal excretion of metabolites.

Storage. Store at controlled room temperature (20-25°C / 68-77°F). Protect from light. Oil-based solution - do not refrigerate or freeze. Draw with a larger gauge needle and inject with a smaller one (18G draw, 23-25G inject). Keep out of reach of children and in a locked location - Schedule III controlled substance in the United States.

06

Regulatory status

Schedule III controlled substance in the United States under the Anabolic Steroids Control Act of 1990. Never FDA-approved for human use. Veterinary approval (Equipoise, Fort Dodge) for horses has been restricted in recent decades. Possession or distribution without a valid prescription is a federal offense in the United States. Classified similarly in most international jurisdictions.

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