"Diuretics are drugs that increase the rate of urine production by the kidneys, resulting in a loss of water and electrolytes from the body. In bodybuilding, diuretics are sometimes used to help reduce water retention in the body and promote a more defined and muscular appearance on stage. The use of diuretics in this manner is sometimes referred to as "cutting water weight" [21]. However, the misuse of diuretics can have serious health consequences. By increasing the rate of urine production, diuretics can cause dehydration and electrolyte imbalances, leading to muscle cramps, dizziness, fainting, and even death in severe cases. The loss of electrolytes such as sodium and potassium can also negatively affect the heart, leading to arrhythmias and other cardiovascular complications [22].

"Moreover, the use of diuretics can also put a significant strain on the kidneys. The kidneys are responsible for filtering the blood and removing waste products, and diuretics can increase the workload on these organs. Long-term use of diuretics can lead to kidney damage, impairing their ability to function properly and ultimately resulting in kidney failure [23]. In addition to these health risks, using diuretics in bodybuilding is prohibited by many athletic organizations and can result in disqualification and other penalties. Therefore, bodybuilders need to avoid the misuse of diuretics and instead focus on healthy and sustainable approaches to achieving their desired physique [24]."

Source

Mantri S, Agarwal S, Jaiswal A, Yelne S, Prasad R, Wanjari MB. Bodybuilding: A Comprehensive Review of Performance-Enhancing Substance Use and Public Health Implications. Cureus. 2023 Jul 9;15(7):e41600. doi: 10.7759/cureus.41600. PMID: 37559855; PMCID: PMC10409494.