# Testosterone Undecanoate (MCT Oil)

*Also known as: TU MCT, Testosterone Undecanoate*

MCT-carried testosterone undecanoate; shorter apparent half-life than the castor-oil formulation.

## Overview

Testosterone undecanoate in MCT oil is an alternative carrier formulation of the longest-acting testosterone ester, differing from the castor-oil reference product in its carrier oil and apparent release rate. The long undecanoate ester chain is cleaved slowly by tissue esterases to release free testosterone, and the MCT carrier yields a somewhat shorter apparent half-life than the castor-oil reference, allowing less frequent but still very widely spaced dosing. The compound has a roughly 480-hour half-life, about 65% bioavailability, and supports dosing every 8 to 12 weeks for replacement. Effects are sustained replacement-level testosterone with minimal peak-to-trough variation, while the very long half-life means dose changes take months to fully reflect in serum levels. Harm reduction centers on understanding that apparent pharmacokinetics vary by carrier oil and injection volume and on the patience required when adjusting dose given the multi-week transition to steady state.

## Pharmacokinetics

- **Model tier:** advanced
- **Half-life:** 20.0 days (480 hours)
- **Cmax:** 750 ng/dL
- **Tmax:** 8.5 days
- **Bioavailability:** 65%

## Dosing

- **Default dose:** 750 mg
- **Typical range:** 500–1000 mg
- **Units:** ng/dL

## Harm reduction

- **Aromatizes:** Yes
- **DHT derivative:** No
- **Injection frequency:** Every 8–12 weeks

## Source

- **Label:** Estimated PK (MCT carrier)
- **URL:** https://onlinelibrary.wiley.com/doi/full/10.2164/jandrol.109.009597
- **Notes:** Cmax calibrated to ng/dL serum peak; MCT carrier yields a shorter apparent half-life than castor.

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