Weight loss supplements rarely work, can be dangerous: study

Weight loss supplements rarely work, can be dangerous: study

Weight loss supplements rarely work, according to a new Consumer Reports study.

The product ratings group surveyed 3,000 Americans and found that out of those who have used diet pills (almost one in four people), only 9% of them were able to lose the weight they wanted and maintain their weight loss. And that may not even be due to the pills — 85% of those weight-loss-success stories also involved diet and exercise changes.

"The barrage of advertising leads us to think there's a magic way to melt away 10 pounds — even when we have no evidence that supplements work," said Dr. Pieter Cohen, M.D., a physician at Harvard Medical School and the Cambridge Health Alliance who studies supplements.

Twenty percent of users thought that supplements were approved by the Food and Drug Administration and therefore safe — when in reality, they don't require the same regulations as prescription pills.

Twenty percent of users also got tripped up by a "natural" label on their pill canister, thinking that word meant the product was safe. But the label doesn't mean much: Some supplements were recently shown to contain banned substances, and people can have side effects on supplements just like they do on prescription pills. In fact, about half of the survey respondents said they had at least one side effect after taking a supplement, including ones not meant for weight loss.

"There's no way to know what's in the bottle," Cohen said. "You're at the mercy of the manufacturer."

Alarmingly, the majority of respondents said they don't tell their doctor about supplements they take.

"These products can interact with prescription medications, but consumers often feel that supplements are different from prescription drugs, and doctors don't ask about them," Cohen said.

Why you should skip weight loss drugs

Year approved: 2012

How it works: This medication promotes weight loss by activating brain receptors for serotonin, a neurotransmit­ter that triggers feelings of fullness.

Typical results: After a year, those taking lorcaserin lost only 6 pounds more than those who took a placebo. After another year, participants gained back about a quarter of the weight they had lost. Some had trouble trouble staying on the drug due to side effects.

Side effects: The drug can cause headaches, dizziness, fatigue, nausea, constipation, memory and attention problems, and (rarely) a leaky heart valve. As a result, the FDA has required the manufacturer to conduct studies to rule out heart problems. Like many prescriptions, Belviq can also interact dangerously with other drugs. If you take it with antidepressants or a migraine medication, for example, you can develop serotonin syndrome, which is characterized by agitation, diarrhea, a fast heart rate, and hallucinations.