Boldenone Cypionate
A shorter-ester alternative to the familiar boldenone undecylenate (Equipoise), pairing the same 1-dehydrotestosterone steroid with a cyclopentylpropionate ester. It offers the boldenone profile — slow lean gains, appetite stimulation and pronounced erythropoiesis with modest aromatisation and no progestogenic activity — but with faster clearance than the undecylenate. Human data are minimal; it exists almost entirely as an underground product.
01 Overview
Boldenone cypionate delivers the same active steroid as boldenone undecylenate but with a medium-length ester, shortening the half-life relative to the very long undecylenate. Boldenone is testosterone with an added 1,2 double bond — the injectable, non-alkylated analogue of methandrostenone — which reduces aromatisation and abolishes progestogenic activity.
Unlike the undecylenate, the cypionate ester has no meaningful clinical history and is a purely underground preparation, so its evidence base is anecdotal and inferred from boldenone pharmacology. Its defining practical feature is a strong rise in red blood cell count, alongside steady lean gains and appetite stimulation over shorter cycles than Equipoise typically requires.
02 Mechanism
Androgen-receptor agonist increasing protein synthesis and erythropoiesis; the 1,2 double bond lowers aromatisation versus testosterone and it does not activate the progesterone receptor.
03 Dosing
| Tier | Dose | Route | Notes |
|---|---|---|---|
| Common | 300–500 mg/wk | IM | Shorter ester than undecylenate; split weekly. |
| Heavy | 600–700 mg/wk | IM | Higher haematocrit burden. |
Ester comparison
| Ester | Half-life | Injection freq. | Testosterone by mass |
|---|
04 Effects
| Effect | Magnitude | Evidence | |
|---|---|---|---|
| Slow, lean muscle gainSteady lean accrual with little water retention, inferred from boldenone use. | Anecdotal | ||
| Increased appetiteBoldenone is well known anecdotally for strong appetite stimulation. | Anecdotal | ||
| Increased red blood cell countPronounced erythropoietic effect characteristic of boldenone. | Preclinical |
05 Side effects
| Effect | Severity | Frequency | Evidence | Countermeasures |
|---|---|---|---|---|
| Mild oestrogenic effectsSome water retention or gynaecomastia at higher doses despite reduced aromatisation. | Mild | Uncommon | Anecdotal | |
| PolycythaemiaMarked rise in haematocrit increasing blood viscosity and thrombotic risk. | Moderate | Common | Observational | |
| HPTA suppressionSuppresses endogenous testosterone and gonadotropins. | Severe | Universal | Observational |