By Joan Raymond
Updated February 22, 2008

Karen Mullin had always been able to eat what she wanted with no worries of packing on pounds—until she began battling “middle age spread” last year at age 44. Despite eating right and exercising, the scale wouldnt budge. Frustrated, Mullin took Ritalin, a drug used to treat attention deficit hyperactivity disorder, “borrowing” it from a friend. One of its side effects is weight loss, making it a popular diet drug for everyone from soccer moms to starlets. “You hear about how some drugs like Ritalin can just melt the pounds off,” she says, “so you figure why not?”

Should you try it?
Mullin tried the drug only once on a lark without a doctors guidance (not recommended). But more docs, frustrated with the handful of U.S. Food and Drug Administration (FDA)–approved weight-loss drugs with inconsistent results, are prescribing medications that are used to treat everything from depression to seizures—all with the side effect of weight loss—to help patients drop pounds. (More weight-loss-drug options are coming soon, though; see page 98 of Health's April issue.)

For doctors, this off-label prescribing is legal. In fact, a study that appeared recently in the Archives of Internal Medicine suggests that 21 percent of prescriptions for 160 common drugs (some 150 million prescriptions) are being written to treat conditions for which they arent specifically approved. But some experts believe it can set both patients and their doctors up for big letdowns.

Risky business?
For most of us—including Mullin—the possible benefits of taking a weight-loss drug, off-label or not, usually dont justify the risks, which can include osteoporosis and more (see “Off-Label Drugs: What You Need to Know,” at right). Besides, casual dieters who want to drop just a few pounds arent good candidates for any medication: Thats usually reserved for those with a BMI of 30 or more.

And getting drugs without a doctors supervision from prescription-free Internet sites or a friend can be dangerous, says Michael Steelman, MD, past president and chairman of the board of the American Society of Bariatric Physicians. You could set yourself up for potentially deadly electrolyte imbalances, or nutritional deficiencies, he says.

Losing the right way
Even doctors who prescribe off-label are cautious about setting up unrealistic expectations. “A pill can make a person less hungry, but it cant tell them how to eat,” says Michael Anchors, MD, who holds a patent on Phen-Pro, an off-label weight-loss combo that blends the FDA-approved weight-loss drug phentermine along with an antidepressant like Prozac.

A comprehensive weight-loss program that includes nutrition education and exercise is the only way to keep pounds off long-term, Anchors explains. Thats why he prescribes lifestyle changes along with Phen-Pro. Its working for Marianne Greenhouse, one of Anchors patients, who tipped the scale at 300 last year then lost 50 pounds in six months. “Now I feel like I have a future,” she says.

The bottom line
Most people can successfully lose weight with a combination of diet and exercise—and an FDA-approved weight-loss drug, if necessary, says Karen Cooper, doctor of osteopathy, at the Bariatric and Metabolic Institute at the Cleveland Clinic, a top bariatric-surgery hospital. Before taking any drug, though, make sure you understand its risks and benefits. And, above all, dont self medicate.

Be honest with your doctor about previous weight-loss efforts, too, so she can decide if medication is the right choice for you. “A drug might help you lose weight, but its not going to keep the weight off,” Cooper says. “That takes commitment. And no drug, whether approved or off-label, can help you with the long-term commitment you need.”

As for Mullin, shes given up on any quick fixes and stays as active as possible. “I take the stairs. I park farther from the door. And I make two trips to the mailbox; I no longer roll down my car window and pick it up.”

Off-label drugs: What you need to know

  • Adderall Ritalin
    Generic: Amphetamine, methylphenidate
    FDA-approved use: Attention deficit hyperactivity disorder, narcolepsy
    Notable side effects: Insomnia, chest pain; also can be habit forming

  • Wellbutrin Zyban
    Generic: Bupropion
    FDA-approved use: Depression, smoking cessation
    Notable side effects: Hallucinations, seizures

  • Topamax
    Generic: Topiramate
    FDA-approved use: Epilepsy, bipolar disorder, migraines
    Notable side effects: Osteoporosis, slurred speech