15 Dianabol Side Effects Bodybuilders, Athletes, Male & Females

Clenbuterol (often abbreviated "clen") is a synthetic sympathomimetic amine that belongs to the class of β₂‑adrenergic agonists. It is commonly known for its use as a bronchodilator in veterinary medicine and, more controversially, for weight loss or performance enhancement in humans.



---




1. What Clenbuterol Does



Target Primary Effect


β₂‑Adrenergic Receptors (in skeletal muscle) Stimulation → increased glucose uptake, glycogenolysis, lipolysis, and mild hypermetabolism.


Cardiac β₁/β₂‑Receptors Mild chronotropic effect (slight increase in heart rate).






In animals it relaxes bronchial smooth muscle, easing breathing in asthmatic or obstructive lung disease.


In humans, the lipolytic (fat‑burning) and thermogenic effects are most sought after.







2. Pharmacokinetics (PK)



Parameter Typical Value (Based on Literature)


Absorption Oral bioavailability ~40 %–50 %. Peak plasma concentrations reached within 1–3 h post‑dose.


Distribution Volume of distribution (Vd) ≈ 0.6–0.8 L/kg; moderate tissue penetration, including fat and brain.


Metabolism Primarily hepatic via CYP2D6 and CYP3A4 oxidation → 4-hydroxy derivative (inactive).


Half‑life (t½) ~12 h in healthy adults; may extend to 18–24 h in poor metabolizers.


Elimination Renal excretion of metabolites;