Clenbuterol®, also known as Clen, is a bronchodilator and beta-agonist that is primarily used to treat breathing disorders or lung diseases such as asthma. It is, however, also widely used as a weight-loss supplement or bodybuilding supplement. This drug, which also acts as a decongestant, causes burning of body fats to be used as energy, thus resulting in increased body temperature. There are several Clenbuterol® side effects that may manifest themselves when someone is taking this drug. These include elevation of blood pressure, insomnia, muscle cramps, and excessive sweating.

One of the Clenbuterol® side effects that affects both men and women is high blood pressure. This drug acts as a stimulant, so it has the tendency to increase a person's heartbeat, which may result in the elevation of blood pressure. Clenbuterol® should not be used by anyone who has hypertension or high blood pressure.

Another of the side effects of taking Clenbuterol® is insomnia. Insomnia is a condition where an individual has difficulty falling asleep. This is due to the stimulant effect of Clenbuterol®. Individuals taking this drug and at the same time consuming greater amounts of caffeine frequently experience severe insomnia.

Clenbuterol® can affect the central nervous system, causing an individual to sweat excessively. Women may experience more intense sweating at some point in their hormonal cycle. According to some users, however, sweating is an expected Clenbuterol® effect and is a sign that the drug is working. Other Clenbuterol® side effects are nervousness, nausea, muscle tremors, and heart palpitations. After a week or more of taking the drug, some individuals may become used to it, thereby gradually reducing the manifestations of Clenbuterol® side effects.

Clenbuterol® has been used by athletes and bodybuilders as this drug may help build bigger muscles. Short-term use frequently helps them to lose body fat and increase muscle mass before a competition. It is frequently advised to use Clenbuterol® for only a short period, which is about two to three weeks. Longer term use of Clenbuterol® can lead to heart damage or heart failure.

There are several contraindications to the use of Clenbuterol®. It must not be taken by individuals suffering from cardiac rhythmic disturbances or those with cardiovascular diseases. Pregnant women are advised against taking this drug. Some countries also consider the use of Clenbuterol® illegal; it is not approved for use by humans in the US. Several international sporting agencies list it as a performance enhancing drug.