1. Chronic Obstructive Pulmonary Diseases
COPD is a group of progressive lung disorders that obstruct air flow, making it difficult to breathe. Various studies on human and animal models confirm the effectiveness of clenbuterol in treating respiratory disorders. Researchers designed a study to check the efficacy of this drug in the management of asthma in children. The results found that clenbuterol showed substantial effects as compared to the placebo. Furthermore, a single dose of 1ug/kg was found to be most successful in children with a favourable risk/benefit ratio [1].
2. Muscle mass
In addition to bronchodilation, clenbuterol has also been shown to exert anabolic effects. For the time being, it was thought that these effects are independent of beta-2 adrenergic receptors. However, research conducted on rats found contradictory results. Administration of clenbuterol (4mg/kg) resulted in increased protein synthesis, mRNA content and gastrocnemius muscle mass in rats. However, when the researchers administered beta-2 antagonists, these effects were diminished. This indicates that clenbuterol mediates anabolic effects through beta-2 adrenergic receptors [2].
Furthermore, one study was designed to compare the effect of clenbuterol and salbutamol on muscle mass in old and young rats. The researchers found that both drugs had the same effect on muscle mass, but clenbuterol greatly influenced protein synthesis as compared to salbutamol. Based on these findings, researchers suggested that both drugs can be used to prevent muscle loss associated with declining age [3]. These results are also confirmed by randomized clinical trials in humans, concluding that the clenbuterol can significantly boost lean muscle mass and improve lean/fat ratio [4].
3. Weight loss
Clenbuterol is one of the drugs that are widely misused by people for weight loss. There are not many human studies to confirm this effect. A study conducted on horses found that clenbuterol resulted in a significant reduction in fat content, with a 12% decrease observed in working horses and an 8% decrease in non-working horses [5].
The increased weight loss effect of clenbuterol might be attributed to its ability to stimulate thermogenesis. Increased heat production in the body leads to enhanced utilization of calories. Additionally, it possesses lipolytic properties, converting triglycerides into free fatty acids. In a study involving young men, clenbuterol intake was associated with a 21% increase in energy expenditure and a 39% rise in fat oxidation [6].
4. Amyotrophic Lateral Sclerosis
Amyotrophic Lateral Sclerosis(ALS) is a progressive neurodegenerative disease that affects the nerve cells in the brain and spinal cord. It primarily targets motor neurons, thus leading to loss of motor function and muscle weakness. Clenbuterol has been shown to have neuroprotective and muscle-strengthening effects, thus it might be able to resolve the symptoms of ALS. A small open-label trial found that clenbuterol at the dose of 40-80 ug slowed down the progression of disease [7].