Clenbuterol (Spiropent) is a beta-receptor agonist drug used in the treatment of asthma and in bodybuilding for the purpose of fat loss. In some instances, it can also be used to enhance performance in endurance exercise.
When to use clenbuterol
Clenbuterol should only be used when fat loss needs to be particularly accelerated over a relatively short period of time. For example, if the need or intent is to lose only 1 lb of fat per week, then there are better means to do this than to use clenbuterol. Where fat loss efforts are already maximized or near-maximized, however, clenbuterol use can add perhaps another 1 lb per week to the rate of loss.
Dosage and cycling of clenbuterol
The effective dose range of clenbuterol extends from 20 mcg/day as a minimum value to 40-140 mcg/day as more common values. I think it best to start at 40 mcg/day and evaluate results on an ongoing basis, increasing dose by 20 mcg at a time as necessary. Many users adjust dosage to the level where the hands begin to shake, but fat loss can be improved markedly with doses well below this point.
Clenbuterol should be cycled rather than used continuously or for prolonged periods of time, but no exact cycling pattern is necessary. Period of use is typically from 2 to 8 weeks.