Clenbuterol

Evidence: ★★★☆☆ · Status: Not Approved, Controlled

💡 Did you know? Clenbuterol isn't a steroid — it's an asthma drug that raises metabolism, and it's why some countries test their meat supply for it.

In plain English

A veterinary asthma drug that cranks up fat-burning and body heat while sparing muscle. It also strains the heart, causes shakes and cramps, and can cause cardiac damage.

How it works

Long-acting beta-2 adrenergic (ADRB2) agonist: activates adenylate cyclase → cAMP → PKA → hormone-sensitive lipase (lipolysis) and upregulates UCP-1 in brown fat (heat instead of ATP). Mild anti-catabolic effect on muscle.

Molecular target & official sources

ADRB2 (NCBI Gene) · UCP1 uncoupling protein 1 (NCBI Gene) · Clenbuterol (PubChem CID 2783)

Watch out

Tachycardia, tremor, cardiac hypertrophy, hypokalemia. Banned in sport and food animals.

Bottom line

Effective and genuinely risky to the heart; illegal for human use in most places.

Helps with: Build Muscle & Strength · Lose Fat · Cardiovascular · Hormones & Testosterone

Stacks with

Shares a pathway — often paired with: Caffeine, Semaglutide (Ozempic / Wegovy / Rybelsus), Tirzepatide (Mounjaro / Zepbound), Metformin.

Availability & where to buy

Controlled substance. A controlled substance in most countries — illegal to buy, sell or possess without authorisation (in Singapore: HSA / CNB). Education only.

How it works: the GPCR → cAMP pathway →

Common questions

Does Clenbuterol actually work?

Human-evidence rating: 3 of 5. Effective and genuinely risky to the heart; illegal for human use in most places.

What are the risks or side effects of Clenbuterol?

Tachycardia, tremor, cardiac hypertrophy, hypokalemia. Banned in sport and food animals.

Is Clenbuterol legal or approved?

Regulatory status: Not Approved, Controlled.