# Clenbuterol (Oral)

*Also known as: Clen*

β2-agonist bronchodilator used off-label for fat loss; cardiac stimulation risk.

## Overview

Clenbuterol is a long-acting beta-2 adrenergic agonist developed as a bronchodilator and veterinary compound, used off-label for fat loss despite not being an anabolic steroid. It stimulates beta-2 receptors, raising metabolic rate and thermogenesis through increased oxygen transport and mitochondrial activity, with measurable effects on lean mass in animal models. The compound has a roughly 27-hour half-life, peak plasma within a few hours, and about 90% bioavailability, supporting once-daily oral dosing, and it is WADA-prohibited with a zero threshold so any detectable amount is a violation. Effects include appetite suppression and fat loss, while tachycardia, tremor, anxiety, electrolyte disturbance, and more serious cardiac arrhythmia are common risks, and effects attenuate rapidly as beta receptors downregulate. Harm reduction centers on understanding the genuine cardiovascular hazard, on never combining it with other stimulants, and on treating it as a sympathomimetic with a narrow safety margin.

## Pharmacokinetics

- **Model tier:** advanced
- **Half-life:** 1.1 days (26.560000008000003 hours)
- **Cmax:** 0.333 ng/mL
- **Tmax:** 0.1 days
- **Bioavailability:** 90%

## Dosing

- **Default dose:** 0.04 mg
- **Typical range:** 0.02–0.12 mg
- **Units:** ng/mL

## Harm reduction

- **Aromatizes:** No
- **Hepatotoxicity:** mild
- **Interaction notes:** Clenbuterol + tadalafil compounds cardiovascular/tachycardia risk.

## Detection time (anti-doping)

- **Window:** 7–14 days post-last-dose
- **Target metabolite:** Parent clenbuterol
- **Assay:** LC-MS/MS
- **Notes:** WADA zero threshold — any detectable amount is an AAF. Parent detectable 7–14 days (dose-dependent).

## Source

- **Label:** PMC clenbuterol PK
- **URL:** https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4694390/

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**Canonical URL:** https://anabolicdex.com/compounds/clenbuterol
**Plot:** https://anabolicdex.com/plot?compound=clenbuterol