Clenbuterol Side Effects

Clenbuterol is a drug designed for use as an antihistamine in veterinary medicine. In humans, it provides stimulant effects similar to amphetamines, such as increased heart rate, body temperature and blood pressure. According to the U.S. Drug Enforcement Administration, clenbuterol is used illegally as an alternative to steroids for muscle growth, fat loss and improved athletic performance. Recreational use of clenbuterol is considered dangerous and poses risks for numerous serious side effects.

Nervousness and Anxiety

Clenbuterol has shown to cause emotional side effects, including severe nervousness, edginess, paranoia and anxiety. According to the medical faculty at University of New South Wales in Sydney, Australia, physical tremors often accompany nervous symptoms. A person may feel shakiness similar to excessive caffeine intake. Hand tremors are common and can lead to reduced ability to partake in physical tasks, such as writing, typing or holding objects steadily. People with depression, anxiety or other psychological disorders may hold heightened risks for these effects.

Sleep Problems

Clenbuterol may trigger sleep problems including insomnia--the inability to fall asleep or remain asleep. Nervous thoughts may keep users of the drug awake at night. The stimulant properties of clenbuterol also inhibit restful sleep capabilities. According to the National Sleep Foundation, stimulants are a major contributing cause of insomnia, which often leads to daytime grogginess, desire for additional stimulants and irritable moods 2. Since mood problems commonly stem from the drug itself, lack of sleep may exacerbate such symptoms.

Heart Problems

Some of the most dangerous side effects caused by clenbuterol involve its effect on the heart. According to the UNSW, heart palpitations, rapid heartbeat and increased blood pressure may occur as a result of clenbuterol. In some cases, rapid heart rate frightens people into not taking them. Unfortunately, many others continue taking the drug regardless. In an interview with the Daily Mail in London in October 2006, substance abuse expert John McVeigh explained that women seeking a waif-thin physique may continue to take clenbuterol due to its thermogenic, or body-heat and heart-rate stimulating, effects 3. However, these effects may contribute to serious health problems, including heart attack, stroke and sudden death.

Weight Gain

Weight loss reaped from clenbuterol is often temporary. According to McVeigh, clenbuterol is considered a way to lose weight without need for exercise or altered eating habits. However, weight gain frequently follows. Cases of sudden, intense weight gain have been reported due to long-term clenbuterol use. Clenbuterol can negatively affect a person's metabolism and result in body weight that exceeds a person's weight before taking the drug.