Clenbuterol
Clenbuterol. Long-acting selective β2-adrenergic receptor agonist (Gs/cAMP). Bronchodilator (approved abroad, not for human use in the US).… Oral half-life 35 h.
Long-acting selective β2-adrenergic receptor agonist (Gs/cAMP). Bronchodilator (approved abroad, not for human use in the US). Abused off-label for fat loss via β2-mediated lipolysis, thermogenesis, and a repartitioning/mild anabolic effect on skeletal muscle. Adverse effects: tachycardia, tremor, hypokalemia, and cardiac hypertrophy/arrhythmia risk; the long half-life prolongs toxicity.
PubChem CID 2783 (free base). NOT a steroid — a β2-agonist. Doses are in MICROGRAMS (20–120 µg/day). PK: Yamamoto 1985 (PMID:4045696) verbatim "The half-life of clenbuterol in plasma was estimated to be about 35 h" in man after oral clenbuterol HCl. PK: THE REAL DEFECT IS A FIELD THAT ISN'T THERE. With no volume the solver silently substitutes half a litre per kilogram and a bioavailability of 0.9, and at the stored typical dose the model predicts a peak five-fold above what THIS RECORD OWN CITED PAPER OBSERVED. Back-solving that paper own figures puts the apparent volume five-fold higher than the default — BUT THAT IS COMPUTED, NOT VERBATIM, and no indexed clenbuterol abstract states a volume or a bioavailability at all, so the gap is logged rather than filled. The half-life is verbatim. The absorption rate is confirmed as a full-precision back-derivation, AND THE PEAK TIME IT WAS DERIVED FROM IS AN UPPER BOUND RATHER THAN A MEASUREMENT — "reached the maximum value ... WITHIN 2.5 h" — so the stored rate is a lower bound on the truth; defensible, and now recorded as derived from a bound. TWO TRAPS ARE FLAGGED FOR WHOEVER FILLS THE VOLUME GAP: the same abstract carries a plasma-binding percentage and a urinary-recovery percentage, both classic donors for a fabricated bioavailability, and a neighbouring paper that looks like a clenbuterol volume is MABUTEROL, a different drug.
Pharmacokinetics
- Oral — t½ 35 h · ka 1.83 h⁻¹
Sources: PMID:4045696