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UC Davis Medical Center

UC Davis Medical Center

Can diet pills help you lose weight?

Checkup on Health

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Drugs can be a help in obesity treatment, but they are not a magic bullet that allows us to shed pounds effortlessly. In addition, tt’s nearly impossible to maintain weight loss without exercise.

By Judith S. Stern, Sc.D.

Everyone knows that a combination of diet and exercise is a basic way to lose weight for many people. But many of us have tried this, over and over again, without lasting success. Still, we know it’s important to take off those extra pounds, both for the sake of our physical health and our state of mind.

Can diet pills help us meet our goals?

Drugs can be a help in obesity treatment, but they are not a magic bullet that allows us to shed pounds effortlessly. A small minority of people do find them a helpful adjunct to a diet and exercise program.

In a study of 2,800 people who lost at least 30 pounds and kept them off for over a year, only 4 percent did it with the use of medications. Another approach is to lose some weight and use medication to help keep the weight off.

Judith Stern is a UC Davis professor of nutrition and internal medicine. She is a member of the National Academy of Sciences' prestigious Institute of Medicine and a co-founder of the nonprofit American Obesity Association and the North American Association for Obesity (now The Obesity Society).

I’ve seen people helped with diet drugs in the short run, but weight does tend to bounce back — despite best intentions and efforts to maintain the hard-won weight loss.

I compare this phenomenon to a person who is diagnosed with high blood pressure and put on medications to bring it down. It works, but don’t expect the blood pressure to stay low when you go off the medications! Our bodies have a strong maintenance system that’s difficult to override, even when it’s sometimes not in our best interest.

It’s also important to remember that no one drug works for all people — just as one drug rarely works to control everyone’s blood glucose or blood pressure.

While today’s weight-loss drugs are not very effective, I do believe that better medications will emerge in the future — allowing physicians to target drugs to individuals as they do, say, with cholesterol medication. As alluded to above, it is likely that these medications will have to be used over the long term.

Limited prescription options

There are only two prescription drugs that are FDA-approved for longer-term use for weight loss. Both are only recommended for people who are significantly obese.

The Food and Drug Administration, or FDA, treats obesity drugs differently than it does other drugs. There are only two prescription drugs that are FDA-approved for longer-term use for weight loss (several others are approved only for short-term use over a few months). Both of the longer-term drugs are only recommended for people who are significantly obese.

Sibutramine (trade name Meridia) increases metabolism and affects serotonin and other neurotransmitters. People report they feel full and more energetic. Because it can increase blood pressure, it must not be used in people with hypertension, and blood pressure must be regularly monitored while using the medication. People with heart disease, stroke and heart rhythm disturbances must also avoid the medication, and it must not be used in combination with decongestants, bronchodilators (used for asthma) or MAO inhibitors (medications used against depression). It is not particularly effective in the long run. FDA requested that Abbott Labs voluntarily with draw Merida due to concerns about increased risk of heart attacks and strokes. In October 2010, Abbott Labs agreed to do so.

The FDA has found undeclared and unapproved sibutramine in some specific dietary supplements, which has prompted voluntary recalls.

Orlistat (trade name Xenical) has helped people to achieve only mild weight loss in studies. It blocks the action of lipase, an enzyme in the intestine that breaks down fat. As a result, 30 percent of fat eaten is not absorbed and is excreted in the stool. It sometimes causes gastrointestinal problems, including a lot of gas, an oily discharge and a frequent need to have bowel movements.

The FDA also approved this drug at a lower dose for over-the-counter use by adults (under the trade name Alli). It was the first and only over-the-counter diet drug to win approval from the agency.

If you try over-the-counter weight-loss remedies, discuss them with your doctor first. Many of them can have profound effects on your health in ways you might not predict.

Beware of over-the-counter remedies

If you try over-the-counter weight-loss remedies, discuss them with your doctor first. Many of them can have profound effects on your health in ways you might not predict.

There are numerous weight-loss remedies available over the counter. But let the buyer beware! Medications are medications, whether or not they are herbal, “natural” or under the jurisdiction of the FDA.

I recommend that if you try any of these alternatives, you do so carefully. Don’t combine them with one another or with other medications, and most importantly, discuss them with your doctor. Many of them can have profound effects on your health in ways you might not predict. Some simply don’t work, despite testimonials where people are paid significant amounts of money for losing weight.

Here are some common — or once-common — over-the-counter dietary aids, including some that are now restricted:

  • Phenylpropanolamine or PPA, once also an active ingredient in decongestants. It has a mild appetite-suppressing effect that usually does not work for long. It should never be used with other decongestants and may cause elevated blood pressure and increase the risk for stroke. In the United States, PPA is no longer sold without a prescription after studies associated it with increased risk of stroke.
  • Ephedrine, ephedra or ma huang, a component in adrenaline. It can cause a rapid heartbeat, increased blood pressure, and even psychosis and seizures. There have been some reported deaths attributed to its use. Do not use these products! After FDA banned PPA, many diet-pill makers reformulated their products with ephedra. However, dietary supplements that contain ephedra have been banned in the U.S. since April 2004, after the FDA determined that ephedra posed an unreasonable risk to those who used it.
  • Chitosan, a component from shellfish that is touted as a “fat trapper.” I wouldn’t waste your money on this one: I have published three different studies that show that the only thing it traps is your money. For example, one study suggested it would take more than seven months to lose a pound of body fat via the effects of chitosan. For women, no fat was trapped.

Some dietary herbal teas contain ingredients that work as laxatives. Over time, they can cause chronic pain and constipation. People then become dependent on their use for bowel movements. However, the Chinese used strong Oolong tea to “control weight” — about 1 ½ quarts a day.

Exercise is crucial, no matter what

It’s nearly impossible to maintain weight loss without exercise. And regardless of one’s weight, the other health benefits it provides are many.

While drugs may be part of the answer to a weight problem for a few people, there’s one method I’d recommend for everyone: exercise. It’s nearly impossible to maintain weight loss without it. And regardless of one’s weight, the other health benefits it provides are many. To begin:

  • Set your own goals.
  • Try exercising five or six days a week.
  • To help, wear a pedometer and record how many steps that you walk a day. 
  • If you walk 3,000 steps daily, gradually add another 500 steps every week until you reach your goal.

Don’t get discouraged. Once exercise becomes a habit, you’ll realize why it’s one “pill” you’ll want to swallow for the rest of your life.

Finally, weight loss is not for everyone. You can be healthier by being physically active and eating a healthy diet — fruits, veggies, whole grains, lean fish, meat or tofu and foods high in calcium like dairy products. Go easy on fried foods.

And ... there are some foods that you love and may not want to give up when you’re controlling your weight. These may have to be eaten in limited quantities. For example, I believe that chocolate is an “honorary vitamin” and I must have a little a day not to become "deficient." Of course, moderation is the key here — you’ll need to program yourself to have just a little bit.

Remember: for any weight-loss plan, it helps to have a support group.

Bottom line, there is no one plan to fit everyone.