Most of us want to believe in “miracle” cures. But if it sounds too good to be true, it is.

Weight-loss formulas
The National Institutes of Health warns against taking any drug combos sold without U.S. Food and Drug Administration (FDA) approval, including herbal mixes that promise big results. “The problem is that many contain stimulants and may be dangerous for people with underlying heart disease, high blood pressure, and other chronic illnesses they may not be aware of,” says Marc Siegel, MD, a New York City physician and author of False Alarm: The Truth About the Epidemic of Fear. “And you may not know how much stimulant you’re getting.” It’s far better to ask your doctor about FDA-approved appetite suppressants or, best of all, exercise and watch what you eat.

Arthritis fixes
Copper bracelets, shark cartilage, honey-and-vinegar mixtures, magnets. If only they would cure arthritis. But it just isn’t so, Siegel says. In fact, copper can cause an allergic reaction. Although there’s no cure for arthritis, rest, exercise, heat, and drugs recommended by your doctor can help.

Colon cleansers
Colonics have been hawked as everything from a toxin remover to a cancer cure. But they only do what your intestinal system does already. Enemas, laxatives, or passing a rubber tube through your rectum and pumping water in and out can be expensive and dangerous. “There’s no evidence that colon cleansing is necessary,” Siegel says. And experts say long-term cleansing can cause anemia, malnutrition, infection, intestinal damage, and even heart failure.

Alzheimer’s cures
Removing silver fillings, zapping your brain with electricity, or taking smart pills won’t keep your memory intact, says Stephen Barrett, MD, a retired psychiatrist who operates www.quackwatch.org. “Reputable drugs for slowing memory loss are only in their infancy. If brain tissue is dead, you can’t revive it with something in a bottle.”