# Testosterone Isocaproate

*Also known as: Test Iso*

Sustanon component with medium duration. Simple model — peak calibrated from sibling esters.

## Overview

Testosterone isocaproate is a medium-chain testosterone ester, primarily encountered as a component of blended ester preparations like Sustanon and Omnadren, and rarely used as a standalone injectable. Tissue esterases cleave the isocaproate ester to release free testosterone, with a release rate that sits between the shorter phenylpropionate and the longer decanoate components of the same blends. The compound has a roughly 74-hour half-life, about 75% bioavailability, and supports twice-weekly dosing to maintain stable serum levels when used alone. Effects are those of testosterone itself, covering replacement-level androgen activity or anabolic effects at higher doses, and the ester aromatizes fully to estradiol and follows standard testosterone monitoring needs. Harm reduction centers on understanding that its pharmacokinetic model is calibrated from sibling esters rather than dedicated human studies and on twice-weekly dosing to avoid trough dropout.

## Pharmacokinetics

- **Model tier:** simple
- **Half-life:** 3.1 days (74.4 hours)
- **Cmax:** 86.5 ng/dL
- **Bioavailability:** 75%

## Dosing

- **Default dose:** 100 mg
- **Typical range:** 50–200 mg
- **Units:** ng/dL

## Harm reduction

- **Aromatizes:** Yes
- **DHT derivative:** No
- **Injection frequency:** 2×/week

## Source

- **Label:** PMC ester review
- **URL:** https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9611952/
- **Notes:** Cmax calibrated to ng/dL serum peak.

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**Canonical URL:** https://anabolicdex.com/compounds/testosterone-isocaproate
**Plot:** https://anabolicdex.com/plot?compound=testosterone-isocaproate