Weight-Loss Potions Have Hidden Surprises

The FDA is concerned that people are taking powerful diet drugs with no knowledge of dose or effect.


The Food and Drug Administration is not the Grinch who stole Christmas for warning just before the holiday that a passel of weight loss drugs—28 to be exact, all currently available over the counter or on the Internet—can be dangerous to people's health. In fact, the agency may be a health savior for lots of people who have been lulled into taking diet potions that might work but bear surprise ingredients, two of which are particularly concerning.

Most of these products contain some level of sibutramine, the active agent in the FDA-approved and controlled weight-loss drug Meridia. Meridia is prescribed (along with a sensible diet) for morbid obesity (a BMI greater than 30) or for those who are overweight and also have complications like diabetes. Sibutramine works on the brain to decrease the yearning for more food while eating by altering some key neurotransmitters like serotonin, norepinephrine, and dopamine. But messing with these brain chemicals can bring other effects, including elevation of blood pressure in a group of patients already prone to hypertension.

Another ingredient the FDA identified in one of the weight-loss products is rimonabant, a drug better known by its brand name, Accomplia. This drug is available in Europe but, because of safety issues, has never been approved by the FDA. No doubt it has many attractive features, including decreasing the desire for food and tobacco and even improving cholesterol levels. But it, too, acts directly on the brain and works its weight loss magic by blocking what are called cannabinoid receptors central to the body's feelings of pain and pleasure as well as hunger. Interfering with these receptors can cause black magic in some patients, inducing serious depression and suicidal thoughts.

And for both of these drugs, which are laced into the hunger-reducing potions the FDA warned about, dose is critical to their effectiveness and to the avoidance of dangerous complications. So, to take any of these hunger-reducing products without knowing what compounds they contain and the dose, and without a doctor's supervision, is lunacy. And that's FDA's concern.

We seem to be eternally searching for a safe weight-loss drug that drops pounds the way statins drop cholesterol and carries a safety profile enabling patients to take the pills on a long-term basis. Unfortunately, that holy grail for obesity has not been found. Many drugs that looked great at first fail miserably when used on a chronic basis—like the notorious combination of two FDA-approved drugs called "fen-pfen" (fenfluramine and phentermine), which became a rage for millions of people until it was pulled from the market in September 1997 because it seriously damaged heart valves in some patients.

That's the core problem: Many agents can play with the body's metabolism or with the brain's sense of satiety and melt away a few pounds for a while, but none have turned out to be a long-term solution.