What Dangers Are Hidden in Your Weight-Loss Supplement?

Many patients struggling with weight problems have learned to be suspicious of new weight-loss drugs promising miraculous results. History is littered with examples of such drugs entering the market, only to be withdrawn or discontinued after the emergence of life-threatening risks, usually to the heart.

Few people realize that one of these dangerous, rejected drugs, sibutramine, is now being given a second life: It is hidden inside some dietary supplements promising a “natural” solution to weight loss.

Sibutramine was pulled from the market by the Food and Drug Administration (FDA) in 2010 for causing heart attack and stroke. The supplements that continue to be laced with the risky drug come in many forms. They are sold as shakes, teas, powders, pills and gel capsules, often through online stores. Some, smuggled into the U.S. illegally, are marketed as traditional Chinese or other “alternative” medicines. Others take advantage of current weight-loss trends, resembling popular products such as green coffee, acai berries or herbal tea.

Consumers taking sibutramine-laced supplements may experience limited short-term weight loss, which gives the impression that the supplement is effective. But these effects are short-lived and come with the same risks that led the FDA to ban sibutramine almost three years ago. Worse, these supplements lack warning labels, contain unpredictable orgdoses of the drug and are sometimes laced with other dangerous active ingredients. Added risks such as these can make tainted weight-loss supplements far more dangerous than the sibutramine pills originally banned by the FDA.

The best way to avoid becoming a victim of laced supplements is to stay away from products that are promoted to help achieve effortless weight loss, whether they take the form of a powder, pill, tea, shake, energy drink or even an FDA-approved pill.

Sibutramine’s history

Sibutramine (once marketed as MERIDIA) received approval from the FDA in November 1997. The drug was approved for weight loss and maintenance when used with a reduced-calorie diet in those meeting the medical definition of “overweight.” Public Citizen immediately identified the drug as risky based on early evidence that it raised blood pressure and increased heart rate. This made the drug especially dangerous for people with hypertension, heart disease, congestive heart failure and other conditions common among people who are overweight. Based on this evidence, the April 1998 issue of Worst Pills, Best Pills News listed sibutramine as Do Not Use.

On March 19, 2002, Public Citizen petitioned the FDA to immediately remove sibutramine from the market for safety reasons. Publicly available material obtained from the FDA showed that from February 1998 to September 2001, there were almost 400 serious adverse reactions in patients taking the drug. The adverse reactions involved 19 deaths from cardiovascular causes, including 10 in people under the age of 50 — three of whom were women under 30.

In 2003, Public Citizen amended its petition with new information: An additional 30 cardiovascular deaths were reported while the FDA delayed taking action in the 18 months following the original petition, resulting in a total of 49 reported deaths.

In 2005, the FDA rejected Public Citizen’s first petition, opting instead to amend sibutramine’s labeling to warn patients that the drug could cause kidney damage. The agency continued to delay banning the drug for years, despite mounting evidence of serious safety risks.

The end for sibutramine finally came after the Sibutramine Cardiovascular Outcomes (SCOUT) trial, a large randomized, controlled clinical trial published in 2009 that found conclusive evidence of deadly harm to patients taking the drug. The SCOUT trial recruited more than 10,000 overweight and obese men and women with a history of cardiovascular disease. All participants received sibutramine for six weeks and participated in a weight- management program. After that, they were randomly assigned to receive either sibutramine or a placebo for the remainder of the study, with the average duration of exposure being 3½ years. The study demonstrated a 16 percent increase in risk of major adverse cardiovascular events (which included nonfatal heart attack, stroke and death) in patients treated with sibutramine compared to a placebo.

In addition to demonstrating once and for all that sibutramine was unsafe, the SCOUT trial also proved that the drug was not very effective, whether used for a short or long period. During the first six weeks, when all participants were taking the drug, they lost an average of just six pounds. Some of this weight loss may have been due to the weight-management program in which subjects also participated. The participants who were randomized to take sibutramine long-term lost just a few more pounds, for a total average weight loss of just 10 pounds after a year. Those randomized to placebo had even worse results: They gained back some of the weight they lost during the first six weeks and ended up with a total weight loss of just over four pounds after a year.

In 2009, Public Citizen submitted a new petition responding to the SCOUT trial and presenting its own analysis of adverse events from the FDA’s database, which included a total of 84 reports of death from cardiovascular causes in people taking the drug, 30 of whom were under age 50. Eventually, the FDA admitted that no patient should be put in the position of trading his or her life for a chance at minimal weight loss. Faced with these overwhelming results, the FDA removed sibutramine from the market in 2010, only after its earlier ban in Europe.

Sometimes you can’t keep a bad drug down

For most bad drugs, an FDA ban spells the end of sales, but the story has been different for sibutramine. The drug has found a new way to threaten American consumers by hiding away as an undeclared active ingredient in dietary supplements marketed for “natural” weight loss.

Sibutramine is an attractive choice for certain dishonest supplement makers because it produces small but not insignificant weight loss and its side effects are not obvious to consumers until it is too late. Lacing an ineffective product with sibutramine makes it seem like the product is really effective, boosting sales.

Since 2008, the FDA has identified at least 119 weight-loss products tainted with hidden active ingredients. All but five contained sibutramine or a related chemical compound, making sibutramine by far the most common drug to be hidden in weight-loss supplements.

Added risks

The sibutramine that now lurks in some dietary supplements is far more dangerous than the pills once dispensed at the pharmacy. This is because lack of adequate warning labels, inconsistent doses and other added undeclared ingredients increase the likelihood of side effects, overdose and harmful interactions with other drugs.

When sibutramine was still on the market, it carried a warning label that helped identify patients at particularly high risk for dangerous side effects (including those who were over 65, had high blood pressure or a history of cardiovascular disease, or were taking certain antidepressants). Sibutramine-laced supplements carry no such warnings, making it more likely that especially high-risk patients will take the drug unknowingly and be injured.

Sibutramine’s label also instructed doctors to carefully monitor patients’ blood pressure and heart rate, and to discontinue the drug if either spiked too high. Supplements are often taken without a doctor’s supervision, making it less likely that these early warnings will be caught before causing permanent damage.

The dosage of sibutramine in a laced supplement also is entirely unpredictable. A group of German researchers published a series of 17 phone calls made to poison control centers between 2005 and 2008, reporting adverse effects to patients who had taken a Chinese weight-loss supplement containing undeclared sibutramine. Sold on the Internet, the supplements contained almost twice the maximum daily dose of prescription sibutramine, which was legally available in Europe at the time. The patients, mostly young women under age 40, reported nausea, vomiting, headache, rapid heart rate and spikes in blood pressure. Two patients who also had been taking drugs for attention deficit disorder and schizophrenia had to be hospitalized for psychiatric treatment.

As if these problems were not enough, weight-loss supplements can be laced with other drugs in addition to sibutramine, including phenytoin (an anti-seizure medication), phenolphthalein (an experimental compound suspected of causing cancer), fenfluramine (a stimulant withdrawn in 1997 for causing heart valve damage) and ephedrine (another stimulant that causes cardiovascular risks). Such toxic cocktails represent a potential for harm that rises well above the risks that led the FDA to ban sibutramine in 2010.

If it sounds too good to be true...

Dietary supplements for weight loss are frequently promoted as miraculous “all-natural” or “ancient” remedies that are safer than FDA-approved drugs. Others are promoted using testimonials or the results of scientific studies. These claims are almost universally worthless. If you see any kind of claim promising an “easy” fix for weight loss, whether it comes from a “natural” product or an FDA-approved pill, you are looking at a product that is likely to do more harm than good.

Manufacturers of laced supplements often represent their products as being natural or derived from traditional medicine to take advantage of customers who believe that natural products are safer than conventional drugs. These claims should not be trusted: While a very small number of natural or traditional remedies do turn out to have benefits when tested with solid research, nothing is guaranteed to be 100 percent safe just because it was used over a long period and derived from living things.

Even “scientific” evidence cannot be trusted if it has not been subjected to adequate assessment, something that is generally only possible when the details of a clinical trial can be reviewed by the FDA or some other institution with specialized, highly trained reviewers. It is very easy to craft a shoddy scientific study that will “prove” that a product works. By contrast, good science tends to be expensive and may show that the product does not work or even that it is not safe. This means that few companies carry out high-quality safety and efficacy testing on their products unless they are forced to do so. Supplement makers are not required by FDA law to test their products for safety or efficacy, and as a result, many “scientific” claims by supplement makers are not based on rigorous scientific evidence. There are, however, some notable exceptions (see box below).

Weight-loss products should be met with special skepticism, because every weight-loss drug ever marketed has carried dangerous side effects. As Public Citizen’s Dr. Sidney Wolfe recently stated, “It is magical and delusional thinking for anyone to believe that a drug will turn off hunger without hitting other targets where it will do harm, usually to the cardiovascular system.” Dietary supplements are even less likely than drugs to provide the miraculous solution, because they are frequently not tested as rigorously.

What You Can Do

Do not purchase products that claim to offer miraculous solutions to health problems, whether the claims are said to be based in science or traditional medicine. Ignore personal testimonials by consumers or doctors claiming amazing results. A healthy dose of skepticism may actually save your life. The only safe, effective and sustainable way to lose weight is to eat less and exercise more. Sensible diet and exercise, maintained over a long time, will improve rather than worsen your cardiovascular risk.