Those who plan to use diet pills need a doctors prescription before they can purchase these weight loss drugs. Due to their perceived side effects, doctors need to thoroughly examine the patient prior to issuance of these prescription diet pills.

These types of diet pills or drugs are closely-regulated by the Food and Drug Administration in the United States. Examples of these drugs that need a doctors prescription are Orilistat, Phentermine and Meridian.

Prescription diet pills are normally subjected to a battery of clinical tests to prove their safety and efficacy as well as to find out its potential health hazards and side effects.

An example of the newly developed prescription diet pill is Xenical, which works in the intestinal tract. This drug is designed to decrease the bodys absorption of fat by as much as 30% during digestion. Studies show that those who use this prescription diet pill for a year can lose close to ten percent of their initial weight.

However, a common side effect of this drug is diarrhea since fat cannot be digested by the body. It is important to follow a low fat diet while taking this prescription pill. Aside from blocking fat, these drugs also block the absorption of essential vitamins that are fat soluble. As such, those taking this type of diet pill will lack essential vitamins such as A, D, E, K and beta-carotene. Dieters should be advised to take vitamin supplements to address this problem.

On the other hand, non-prescription diet pills or diet supplements may either be purchased online or over the counter. Since these pills require minimal approval from the FDA, they are often referred as weight loss supplements.

Before you go to the nearest drug store to purchase prescription diet pills, be sure to bring the doctors prescription. Otherwise, you may opt to buy non-prescription drugs, commonly known as weight loss supplements.