Open up your browser, and you’re immediately bombarded with ads for new miracle drugs guaranteed to help you lose weight without having to diet or exercise. Whether it’s something found in the depths of the Amazon rain forest or a secret compound that doctors don’t want you to know about, there’s no shortage of companies willing to take your hard-earned money and sell you what ultimately turns out to be snake oil.

“This industry perpetuates the false belief that a better body can come from a pill,” says Christopher Ochner, an obesity researcher and assistant professor of pediatrics and adolescent medicine at the Icahn School of Medicine at Mount Sinai Hospital in New York. “These companies know their product doesn’t work, but they advertise it anyway. If you could just take a pill instead of dieting and exercising, everyone would already be doing it.”

Among the most popular supplements seen online are green coffee bean extract and raspberry ketones, which manufacturers advertise as having fat-burning and metabolism-boosting benefits that are “clinically proven” with no side effects. Despite being backed by Dr. Oz, Kylene Guerra​, a registered dietitian with Cleveland Clinic, says these products' claims are bogus​. “None of these products’ claims are backed by independent, third-party research,” she says. “But since these supplements aren’t regulated by the FDA, the manufacturers can make promises they don’t have to deliver on.”

What’s worse, manufacturers don’t have to disclose what their products actually contain, Guerra says. “There are often fillers in there that don’t have to be listed,” she says. “A product can advertise itself as caffeine-free, but still have caffeine in it. And even if the active ingredient the company is touting doesn't have any side effects, the fillers might."

This lack of labeling can be dangerous – a study published last year in the journal BMC Medicine found one-third of the 44 supplements tested didn’t contain the active ingredient listed. Many others contained nuts as fillers, which could potentially be deadly for people with allergies.

Many of these supplements advertise themselves as “natural,” in an attempt to entice people who are afraid of “Big Pharma,” Ochner says. “People want to believe that there’s an herb hidden in the jungle that will burn fat, but the odds are that if there is a secret to weight loss, the companies spending billions of dollars per year researching it will find it first.”

And even the pills Big Pharma has created aren’t worth taking, Ochner says.​ The only over-the-counter weight-loss pill on the market that is tested and approved by the Food and Drug Administration is Alli,​​ ​and while it has been demonstrated to work, it comes with side effects that Ochner says make it not worth taking. “It’s meant to block your body from absorbing some of the fat you eat, which It does,” he says. “But side effects include fatty and oily stool, gas, discharge and more. It’s ridiculous.” Alli could not be reached for comment after several attempts.

[Read: Why You Should Think Twice Before Using Alli or Other Weight Loss Aids.]



So if there is little evidence to back up the weight-loss claims​ and the products are potentially dangerous, why do people continue to buy into these products? “People are desperate for a shortcut,” Ochner says.

And that desperation nets the diet pill industry $1.6 billion annually, according to research presented at the 2010 International Association for the Study of Obesity conference. “The fact is that weight loss takes time and effort. You have to watch what you eat and exercise," Ochner says. "Who wants to do all that? It’s a hell of a lot easier to take a pill rather than work for it.”

What makes it so hard? Quite simply, evolution, Ochner says. "Our body is really good at preventing weight loss, because for the longest time, starvation used to be our biggest problem," he says. "But for the first time, humans are faced with the problem of too much food, and it's incredibly hard to drop all the pounds we're packing on."