Diet pills are weight loss products that are orally ingested. They contain stimulants that speed the metabolism and suppress the appetite. Many diet pills also contain mild diuretics, such as caffeine, to assist in the elimination of excess fluid. There are two broad categories of diet pills: over-the-counter (OTC) diet pills and prescription diet pills.

Over-the-counter diet pills
OTC diet pills are typically inexpensive and easily accessible. Diet pills are not regulated by the Food and Drug Administration (FDA), so there is simply no way of knowing the real risks of a particular product until private studies on it have been conducted and publicized. Examples of diet pill ingredients that have been found to be extremely dangerous (or even deadly) are phenylpropanolamine (PPA), ephedra, aristolochic acid, and tiratricol. The known side effects of other OTC diet pills include dizziness, nausea, excessive urination, chest pain, diarrhea, elevated blood pressure, nervousness, bulging eyes, heart attack, liver and kidney damage, stroke, and seizures. To minimize harm from OTC diet pills, consult your doctor if you are considering the use of a particular product, get a medical examination, and ask your doctor to help monitor how the diet pill is working.

Prescription diet pills
Prescription diet pills, unlike OTC pills, are diet drugs regulated by the FDA and only available through a doctor’s prescription. The dosage instructions are clear and the side effects are carefully monitored. Prescription diet pills are not easily accessible because they are designed for people with serious obesity; doctors are usually reluctant to prescribe the pills to those under a body mass index of 34. Prescription diet pills contain different ingredients and work in different ways. For instance, some pills increase the availability of serotonin, a chemical neurotransmitter that affects mood and curbs the appetite. Well-known prescription diet pills include Dexgenfluramine (Redux) and Fenfluramine (Pondimin).