Some diet pills are natural or homeopathic elixirs, while others need caffeine and other stimulants to be effective. However, they are not classified as addictive since they don't produce the same compulsive need as do many drugs.

Here are a few important safety tips: Don't ever use diet pills in place of eating less food and exercising more, and always get your doctor's approval. Always take the pill with a full glass of water, and always in its original form. Because these pills often contain diuretics, more frequent urination may occur, with dehydration a possibility. So make sure you drink at least eight glasses of water daily. Take only the recommended dosage; too much will increase your risk of side effects. While using diet pills, have your pulse checked regularly. A healthy pulse is less than 86 beats per minute. Stop taking the pills if this number is 90 or higher. The box of diet pills will often contain a diet plan. Be sure to follow it.

Reducing calories is of primary importance in your effort to lose weight. After three months, stop taking the pills. Reports vary on how long you can take phenylpropanolamine. Some reports say for up to 16 weeks, while others claim health problems may occur in under one month.

The two types of diet pills are prescription only and over-the counter.

Prescription only - These require a prescription from a doctor, and work in different ways. Some increase the availability of serotonin, a chemical neurotransmitter in the brain that impacts mood (i.e., they prevent depression and thus reduce calorie consumption). Moreover, serotonin reduces the desire for complex carbohydrates and curbs the appetite.

Over-the-Counter Diet Pills do, on occasion, increase blood pressure dangerously high, even causing stroke. They might contain ephedrine (which is derived from the ephedra--or Ma Huang--herb), known for its potential to increase blood pressure to dangerous levels and even to cause psychotic behavior, seizures, heart attack, stroke, and death.

Knowing your body will help you determine whether you can safely take diet pills. Avoid them if you are allergic to sulfites or tartrazine, or if you are prone to strokes or seizures. Others who should not take diet pills are pregnant women and those with prostate issues, high blood pressure, and heart problems. Also, always be sure to talk with your doctor to be sure the diet pill is right for your age group.