There are many medications on the market that are known to assist in the process of losing weight.  While some of these supplements are safe, many of them can have severe side effects when taken for extended periods of time.  When using a thermogenic drug to lose weight, the body temperature is often elevated and increased heart activity takes place.  There are many clenbuterol side effects on men that are shown to cause some concern.  It should be regulated as to how much of the medication is used and the length of time used should not exceed three weeks.  While men will often see some significant weight loss taking place, the side effects should not be overlooked.