Clenbuterol

Mechanism: Selective beta-2 adrenergic receptor agonist. Increases intracellular cAMP, stimulating protein kinase A, which activates hormone-sensitive lipase for fat mobilisation. Also increases thermogenesis by uncoupling mitochondrial oxidative phosphorylation.

Dosage:

• Starting dose: 20-40 mcg/day
• Typical range: 40-120 mcg/day
• Maximum (experienced users): 140-160 mcg/day (significant side effects above 120 mcg)

Administration:

• Oral tablets, taken in the morning (avoid evening dosing — insomnia risk)
• Dose is ramped up gradually (increase by 20 mcg every 2-3 days until target is reached)
• 2 weeks on / 2 weeks off protocol is most common — beta-2 receptors downregulate rapidly
• Alternative: continuous use with ketotifen (1-2 mg/day at night) to upregulate receptors — allows longer runs

Key Notes:

• Not an anabolic steroid — no impact on testosterone, estradiol, LH/FSH
• Primary use is fat loss via thermogenesis; mild anti-catabolic properties (less significant than AAS)
• Receptor downregulation occurs within 2 weeks — cycling is essential for continued effectiveness
• Taurine depletion is common — supplement 3-5g taurine/day to prevent muscle cramps
• Potassium depletion: ensure adequate dietary intake or supplement
• Side effects: tremors (especially hands), increased heart rate, anxiety, insomnia, muscle cramps, headaches
• Cardiovascular risk: chronic use associated with cardiac hypertrophy — avoid prolonged continuous use
• Do NOT combine with other stimulants (ephedrine, high-dose caffeine) — additive cardiac stress
• Monitor: heart rate, blood pressure, potassium, taurine status. ECG recommended for extended use
• Blood markers: may slightly elevate heart rate-related markers, no direct impact on liver or kidney panels

Stimulants push blood pressure up quickly; the decision tree by BP range: How to lower blood pressure on cycle with telmisartan and nebivolol.