Main Ingredients in Prescription Diet Pills

People use diet pills to help shed unwanted pounds. Some diet pills are available over-the-counter and others require a prescription, but both can produce mild or serious side effects. These medications and supplements help you lose weight in several ways, including decreasing your appetite and inhibiting the digestion of fats. Losing weight with diet pills, but without the necessary lifestyle changes to keep the weight off, can result in regaining all the weight back.

Phentermine

Phentermine is a main ingredient in diet pills that helps you lose weight by decreasing your appetite. Usually prescribed for only three to six weeks, this diet pill may become habit forming. According to Medline Plus, phentermine comes in extended-release capsules and tablets that should be taken with meals. It warns that phentermine may produce several mild side effects including dry mouth, diarrhea and constipation. More serious health complications known to occur from phentermine include heart palpitations, ankle swelling, dizziness, tremors and increased blood pressure. Medline Plus urges individuals taking phentermine to keep all doctor and laboratory appointments to monitor your response to this diet pill.

Orlistat

Orlistat is an ingredient in diet pills prescribed to help overweight individuals with high blood pressure, high cholesterol, diabetes or heart disease, according to Medline Plus. Generally prescribed in addition to a low-fat diet and exercise, this pill prevents some of the fat from the foods you eat from being absorbed by the intestines. The most common health complications from orlistat are related to bowel movements, according to Medline. Users experience side effects including flatulence with oily spotting, difficulty controlling bowel movements, headache, irregular menses and anxiety. More serious side effects include difficult breathing, severe stomach pain, vomiting and excessive weakness.

Sibutramine

Sibutramine is the main ingredient in prescription diet pills used for initial weight loss and the maintenance of weight loss, according to PubMed Health, a National Institutes of Health website. This medication does not work for everyone and should be used in conjunction with exercise and a reduced-calorie diet. PubMed Health warns sibutramine can be habit-forming and you must follow the directions of your doctor exactly. Health complications from sibutramine include constipation, runny nose, back pain and painful menstrual periods. PubMed Health cautions patients to look out for serious side effects including excessive sweating, fainting, confusion, fever, seizures, swelling of the throat, unusual bleeding and difficulty speaking.