Clenbuterol 40 mcg is used in bodybuilding as a stimulant “cutting” agent to increase fat loss, enhance muscle definition, and suppress appetite during calorie deficits. Users often start at 20–40 mcg/day and may titrate upward in short cycles to mitigate β2‑receptor desensitization, though protocols vary and lack medical endorsement. Claimed benefits stem from β2‑agonism that elevates metabolic rate and lipolysis.