254 In the index

Clenbuterol CLEN

A powerful drug approved only for veterinary use (as an asthma treatment for animals, not humans) that also shifts the body toward more muscle and less fat. Documented cases of human misuse and accidental exposure confirm it does burn fat, but it comes with serious heart risks like a racing or irregular heartbeat.

Also known as Clen, Spiropent, Planipart, Clenbuterolum, Contraspasmin, NAB 365, (+-)-clenbuterol, XTZ6AXU7KN, CHEBI:174690

Effects Lose fat

Routes Oral

Legal status Prescription drug

WADA Banned at all times

3D Molecular Structure of C₁₂H₁₈Cl₂N₂O

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Chemistry

Formula: C12H18Cl2N2O
Molar mass: 277.19
CAS: 37148-27-9
PubChem CID: 2783
IUPAC name: 1-(4-amino-3,5-dichlorophenyl)-2-(tert-butylamino)ethanol
InChIKey: STJMRWALKKWQGH-UHFFFAOYSA-N

Reported dosing

User-reported

What has been reported in the literature and by users. This is a record of what is done, not a recommendation.

Typical dose 20-40 mcg/day, titrated upward

Reported range 20-140 mcg/day

Route Oral

Frequency Once daily, often in a 2-days-on/2-days-off pattern

Duration 2-6 week cycles (unregulated use)

Not FDA-approved for human use in the US and illegal to sell for human consumption there (approved only as a veterinary bronchodilator elsewhere). Off-label bodybuilding use carries real cardiac risk.

Where this comes from Veterinary pharmacology data; user-reported/bodybuilding literature

There is no approved human dosing for this compound. The figures above are what users and vendors report, not what has been established as safe or effective. Treat them as a record of what is done, not as guidance.

Variants

Name	Abbr	Route	Notes
Clenbuterol hydrochloride	CLEN-H	Oral	The salt form actually sold and dosed.