Are They Safe?
One of the biggest concerns for anyone considering a weight loss drug is its safety. The fear is understandable. The much-touted combination of weight loss drugs called fen-phen -- phentermine and another drug, fenfluramine -- was found to cause dangerous damage to the heart valves in some people. As a result, both fenfluramine and Redux, another similar weight loss drug, were pulled from the shelves in 1997. On its own, phentermine is considered safe and still used.
Being cautious about any weight loss drug is good policy. None of these drugs have been around that long, and so we can't be sure of their long-term effects.
Xenical can cause gastrointestinal side effects, such as spotting, an urgent need to go to the bathroom, and an increased number of bowel movements. These side effects tend to fade over time, and are aggravated by eating a high-fat meal. Xenical can also reduce the amount of vitamins that your body absorbs, so you may need to take a multivitamin to compensate.
But researchers have found no side effects like those of fen-phen.
"Any medication carries risk," says Wyatt. "But at this point, I think that [Xenical and Meridia] are as safe as any other medication that we routinely prescribe." In fact, because of the fen-phen debacle, she thinks that weight loss drugs may be held to an even higher level of safety than other types of medicine.
Wyatt also observes that the very small risks of these drugs have to be compared to the real risks of obesity, such as high blood pressure, diabetes, stroke and heart disease. For people who are very obese, another way to frame the choice could be to compare the low risks of weight loss drugs with the higher risks of bariatric surgery, often called stomach stapling.
The Future of Weight Loss Medications
Many doctors and researchers hope the weight loss drugs of the next decade will make Xenical and Meridia look crude. As researchers learn more and more about the complex set of mechanisms that regulate our weight, the drugs we use will become increasingly sophisticated.