Find a Doctor
Weight Loss Medications: An Easy Solution to Slimming Down?

Weight Loss Medications: An Easy Solution to Slimming Down?


It's no secret that in this day and age, we want things fast, cheap, and with minimal effort on our part. The less time and energy required to achieve our goals, the better. When it comes to losing weight, our attitude is generally no different. It should come as little surprise, then, that in the ongoing battle against the bulge, the pharmaceutical industry has developed weight loss drugs to make it easier for us to attain slimmer, more ideally proportioned figures. Weight loss medications have been used for years to help overweight individuals shed excess pounds, but just how safe are these drugs? And how effective are they at fighting flab? If you’re thinking about using prescription weight loss pills, these are questions you should consider carefully.

How Weight Loss Medications Work

Currently, there are three prescription weight loss drugs on the market. These medications are approved for the treatment of individuals with a body mass index (BMI) of at least 30 (or 27 if the patient has an obesity-related condition such as diabetes or high cholesterol). A person with a BMI of 30 is considered clinically obese, so these medications are not intended for slightly overweight people looking only to lose a few pounds.

Of the three available weight loss drugs, Phentermine has been on the market the longest. Since it is generic, it is also the least expensive. Phentermine was the "phen" in the infamous weight loss cocktail known as fen-phen, a drug that was pulled from pharmacies in 1997 after studies linked it to cardiovascular problems, including heart valve leakage and backflow of blood. According to the FDA's website, Phentermine remains on the market because there have been no reports to connect the drug with the heart problems associated with fen-phen. Phentermine helps patients lose weight by acting as an appetite suppressant, tricking the body into believing it's satiated by modulating the neurochemicals that affect appetite.

MERIDIA® , approved by the FDA in 1997, is also an appetite suppressant. It works primarily by altering the brain's levels of norepinephrin and serotonin – the "feel good" chemical that produces a sensation of fullness after a meal.

The most recent weight loss drug to receive FDA approval is XENICAL®. Released onto the market in 2000, XENICAL® promotes weight loss by inhibiting the body's ability to break down and absorb dietary fat. XENICAL® reduces total fat absorption by about 30 percent; the fat which the body does not digest is eliminated as waste. An over-the counter version of XENICAL®, called alli®, became available in June 2007. Alli® and XENICAL® are essentially the same drugs except that the former is sold in 60 mg doses while the latter is sold in 120 mg doses.

How Effective Are These Drugs?

Individuals looking for a quick fix to their weight problems will be disappointed with prescription medications. Studies show that weight loss drugs provide only modest benefits, and the results usually are slow in coming. For example, MERIDIA® and XENICAL® produce an average weight loss of five to twenty-two pounds over the course of a year. It should be noted, however, that these results are better than what is typically achieved with drug-free treatments.

Another drawback of weight loss medications is that they fail to work in a substantial number of patients. The reason is that the outcome of any patient's treatment is dependant on several factors, including the patient's eating habits, genetics, and lifestyle. Because of this, doctors strongly recommend that patients taking weight loss drugs make healthy lifestyle changes, such as decreasing their caloric intake and increasing their activity level. Such changes not only help the patient to lose weight, but they also help to ensure that the weight stays off once use of the drugs is discontinued.

A team of researchers in Canada and Brazil recently published an article in the British Medical Journal (BMJ) on the effectiveness of MERIDIA® and XENICAL®. The researchers found that although these drugs provide only moderate weight loss results, they may supply patients with important health benefits. In the study, participants taking MERIDIA® remained overweight – losing an average of only nine pounds – but experienced improved cholesterol levels. Patients who were given XENICAL® also remained overweight, with an average weight loss of just seven pounds, but exhibited reduced diabetic symptoms and improved cholesterol and blood pressure levels.

Commenting on the study, Dr. Susan Jebb, head of Britain's Medical Research Council, said that even modest weight loss can result in significant health benefits, such as decreased risk of heart disease and diabetes.

Are There Any Side Effects?

All prescriptions drugs may cause side effects, and weight loss medications are no exception.

Common side effects of Phentermine and MERIDIA® include:

  • Headache
  • Dry mouth
  • Constipation
  • Lightheadedness
  • Insomnia
  • Increased heart rate
  • Increased blood pressure

Phentermine may also cause psychological side effects such as anxiety, depression, and irritability. In the study cited above, up to 20 percent of the subjects taking MERIDIA® suffered side effects including nausea, insomnia, and increased heart rate and blood pressure.

XENICAL®'s side effects primarily involve the gastrointestinal system, since the drug affects the way food is digested. Potential side effects of XENICAL® include:

  • Frequent and/or uncontrollable bowel movements
  • Diarrhea
  • Stool leakage
  • Abdominal cramping
  • Bloating
  • Flatulence

Up to 30 percent of the patients in the BMJ study who were given XENICAL® experienced intestinal side effects.

It should be noted that in addition to inhibiting fat absorption, XENICAL® also blocks the absorption of certain vitamins and nutrients. As a result, patients using XENICAL® should take a daily multivitamin at least two hours before or after taking the medication.

One last thing people may want to consider before trying MERIDIA® or XENICAL® is that the long-term side effects of these drugs are unknown. Both of these medications are relatively new, so there is no information on how they’re tolerated when taken for an extended period of time. The longest studies on these drugs have lasted only two years.

Is It Worth the Risks?

Weight loss medications do help people lose weight, and for some, they may be just what the doctor ordered, literally. However, the limited results that they provide and the risks that they pose are more than enough reason to decide to lose weight the old-fashioned way, through diet and exercise. Granted, engaging in a rigorous weight loss program instead of taking medication is easier said than done; however, with strong enough motivation – be it to enhance appearance and increase self-confidence or improve health and avoid life-threatening medical conditions – dramatic weight loss is possible.

Want More Information?

Contact a Doctor Near You.