Clenbuterol Abuse in Bodybuilding and Athletics: Unsupervised Use, Psychological Motivations, and Health Consequences

Abstract

Clenbuterol is a β2-adrenergic agonist originally developed as a bronchodilator but is now often used without supervision for its perceived muscle-building and fat-burning effects. Although it is not approved for human use in many regions, it continues to be used in bodybuilding and athletics for physique and performance enhancement. Its appeal lies in its ability to influence muscle development and fat metabolism. Many individuals use it due to psychological motivators such as body image concerns and a desire for rapid physical changes. However, its use may result in side effects involving the heart, muscles, and overall physical well-being, such as arrhythmias, hypertension, and muscle spasms. In some cases, it has also been linked to accidental exposure through contaminated food. The widespread misuse of clenbuterol raises ethical concerns in competitive environments. More discussion is needed around developing safer methods of achieving similar goals, and there is a need for increased public awareness and caution regarding its use.

Keywords: anabolic agents; athletes; bodybuilding; clenbuterol; doping; performance-enhancing drugs; β2-adrenergic agonist.

Figure 1. Action of clenbuterol (catabolic and anabolic).

Created by the authors based on data from Dutt et al. [12]. cAMP, cyclic adenosine monophosphate; PKA, protein kinase A; Phospho-AKT, phosphorylated protein kinase B; Ub-proteasome, ubiquitin-proteasome; FoxO3, forkhead box O3 (a transcription factor); MuRF1, muscle RING-finger protein-1 (another E3 ubiquitin ligase)