As fat burning supplements flood the market promising effortless weight-loss, people may wonder if there is a downside to these miraculous pills. There are three main ways in which "fat burning" supplements accomplish their mission. Anyone considering taking supplements should have a close look at what the pills actually do.

Fat Blockers

Fat blockers are one of the ways fat burning supplements claim to rid the body of fat. The supplements are usually made from a shellfish derivative called chitosan. Chitosan enters the body, binds to the fat in the food a person has eaten, and keeps it from being absorbed by the body. There are two downsides to this method. First, fat blockers can also prevent the body from absorbing nutrients it needs. Second, that bound fat still needs to leave the body, which it often does in the form of stomach pain, unpleasant anal leakage and diarrhea.

Appetite Suppression

Another common aspect of fat burning supplements is appetite suppression. Appetite is suppressed by manipulating the body's chemicals and hormones to trick the brain into feeling full. Suppressants that take away general hunger are called noradrenergic drugs. These drugs are often cousins of amphetamines, and work by triggering fight-or-flight hormones than interrupt the body's hunger signals to the brain. The other class of suppressants, which are designed to make you feel fuller quicker, work by manipulating serotonin reuptake. The idea is to trigger a sense of well-being that distracts you from the need to eat more. Negative side affects of these drugs vary from a nervous feeling to heart attacks. They also tend to lose their effectiveness as more weight is lost.

Increased Metabolism

Artificially increasing the human body's metabolism, or the speed in which it breaks down and uses nutrients, is a long established method of weight loss. One of the most common drugs used to do this is caffeine. When the body is stimulated by caffeine, it releases hormones into the bloodstream to cue a quickening of metabolism. These hormones are not in infinite supply, and constant stimulation can change the body's ability to regulate itself and its weight. Overuse of metabolism stimulants can also have the opposite of the desired effect, causing the metabolism to slow down in self-preservation. This is one of the reasons caffeine based fat burners do not maintain effectiveness over a long period of time.

So Are They Safe?

Fat burning supplements will usually, to an extent, do what they say they will. Some authorities claim that these types of supplements can safely be used in small amounts, and they can be effective at jump-starting weight loss. But the means the drugs employ to do so involve manipulating the body's natural processes, sometimes to a severe degree. Side effects are to be expected, and the truth is those side affects range from uncomfortable to fatal.

Anyone with any sort of pre-existing heart, hormonal or digestive condition should seriously consider avoiding fat burning supplements. For other people, it remains a personal choice, but one that should be made with a certain degree of wariness.