Home Belviq


Belviq (lorcaserin), is a weight-loss drug approved to treat obesity. Its distributor, Eisai Inc., pulled it off the market in the United States in 2020 at the request of the FDA. The agency cited increased rates of lung, pancreatic and colorectal cancer among Belviq users during a five-year study.

Last Modified: March 21, 2024
Fact Checked
Medically Reviewed

Board-certified physicians medically review Drugwatch.com content to ensure its accuracy and quality.

Drugwatch.com partners with Physicians’ Review Network Inc. to enlist specialists. PRN is a nationally recognized leader in providing independent medical reviews.

Reviewer specialties include internal medicine, gastroenterology, oncology, orthopedic surgery and psychiatry.

Why Trust DrugWatch?

Drugwatch.com has been empowering patients for more than a decade

Drugwatch.com has provided reliable, trusted information about medications, medical devices and general health since 2008. We’ve also connected thousands of people injured by drugs and medical devices with top-ranked national law firms to take action against negligent corporations.

Our team includes experienced medical writers, award-winning journalists, researchers and certified medical and legal experts. Drugwatch.com is HONCode (Health On the Net Foundation) certified. This means the high-quality information we provide comes from credible sources, such as peer-reviewed medical journals and expert interviews.

The information on Drugwatch.com has been medically and legally reviewed by more than 30 expert contributors, including doctors, pharmacists, lawyers, patient advocates and other health care professionals. Our writers are members of professional associations, including American Medical Writers Association, American Bar Association, The Alliance of Professional Health Advocates and International Society for Medical Publication Professionals.

About Drugwatch.com

  • Assisting patients and their families since 2008.
  • Helped more than 12,000 people find legal help.
  • A+ rating from the Better Business Bureau.
  • 5-star reviewed medical and legal information site.
Learn More About Us


"Drugwatch opened my eyes to the realities of big pharmacy. Having a family member with major depression and anxiety, I was looking for information on her medications. I found information that was very helpful, that her psychiatrist never told her."
Marianne Zahren Patient’s Family Member
  • Google Business Rating
  • BBB A+ Rating Logo

What Is Belviq?

Belviq hit the market in 2012, offering weight-loss hope to people who struggled with obesity. It was also used to treat overweight people who had a serious medical condition, such as high blood pressure, high cholesterol or diabetes.

It was the first weight-loss drug approved by the U.S. Food and Drug Administration in 13 years. Unlike over-the-counter diet pills or appetite suppressants, which are often intended for cosmetic weight loss, Belviq was a prescription drug used to treat obesity.

Obesity and being overweight are two different things. Being overweight simply means weighing too much. Obesity means having potentially dangerous amounts of body fat. Obesity is a chronic condition that can increase a person’s risk for serious health problems, including heart disease, diabetes and certain types of cancer.

One 2022 research report noted that preliminary uncontrolled studies of Belviq in patients with Dravet syndrome, a rare form of epilepsy, have yielded promising results.

How Does Belviq Work?

Belviq (pronounced bell-VEEK) works by controlling appetite. The drug activates serotonin receptors in the brain. Serotonin is a neurotransmitter that triggers feelings of well-being such as satisfaction, gratification and being fully fed.

SSRI antidepressants target some serotonin receptors that play a role in a patient’s mood. Belviq only targets the ones that affect appetite.

People take regular versions of Belviq tablets twice a day. Extended-release tablets are taken only once per day. A person on Belviq is supposed to lose 5% of their weight during the first 12 weeks of taking the drug when coupled with a low-calorie diet. If this amount of weight loss is not achieved, Belviq treatment should be stopped.

Common Side Effects and FDA Cancer Warning

According to the drug’s label, people in clinical trials with and without diabetes experienced some common Belviq side effects. These occurred with more frequency in people taking Belviq than those who took a placebo. Most of the side effects were mild.

Common side effects include:
  • Back pain (in people with diabetes)
  • Constipation
  • Cough (in people with diabetes)
  • Dizziness
  • Dry Mouth
  • Fatigue
  • Headache
  • Hypoglycemia (in people with diabetes)
  • Nausea

Serious side effects included mental changes, cognitive impairment, psychiatric disorders and priapism (an erection lasting more than four hours).

FDA Cancer Warning

On Feb. 13, 2020, the FDA requested that Belviq’s manufacturer, Eisai Inc., voluntarily withdraw the drug over a potential cancer link. The agency based its decision on the results of a five-year study of Belviq users called the Cardiovascular and Metabolic Effects of Lorcaserin in Overweight and Obese Patients – Thrombolysis in Myocardial Infarction 61 (CAMELLIA-TIMI 61) clinical trial.

While the FDA found an overall increased occurrence of cancer in people who took Belviq, the agency saw the most increase in the occurrence of three cancer types: pancreatic, colorectal and lung.

See if You Qualify for a Lawsuit Our Partners

Our Trusted Legal Partners

Drugwatch partners with trusted law firms to help you take legal action. After submitting the form, one of Drugwatch's partners will contact you for a free case review.

simmons hanly conroy law firm logo weitz and luxenberg logo sokolove law firm logo levin papantonio rafferty law firm logo nigh goldenberg raso and vaughn law firm logo morgan & morgan logo the ferraro law firm logo meirowitz & wasserberg law firm logo

Belviq Drug Interactions

Belviq works by activating serotonin receptors. Unwanted reactions may occur if Belviq is taken with other drugs that impact serotonin pathways.

Certain medications and drug classes may interact with Belviq, including:
  • Antipsychotic agents
  • Bupropion
  • Dextromethorphan
  • Dopamine agonists
  • Lithium
  • Monoamine oxidase inhibitors
  • St. John’s wort
  • Selective serotonin reuptake inhibitors
  • Serotonin-norepinephrine reuptake inhibitors
  • Tricyclic antidepressants
  • Tramadol
  • Triptans
  • Tryptophan

The drug cabergoline may also interact with Belviq. This medication is used when the body produces too much of the hormone prolactin.

What People Who Took Belviq Should Do

The FDA recommended that people stop taking Belviq and talk to their doctors or other health care professionals about alternatives. It also advised that doctors stop prescribing and dispensing the drug. And it recommended that doctors contact patients taking Belviq and warn them about the cancer risk. The agency did not recommend any special cancer screening for people on Belviq.

The FDA advised people to safely dispose of any unused Belviq at a neighborhood drug takeback location. If there is no nearby takeback center, do not crush Belviq pills. Instead, mix them with dirt, cat litter, used coffee grounds or some other unappealing material. Place the mixture in a sealed container or plastic bag. Throw the mixture into your home trash can.

People who developed cancer after taking the drug have filed Belviq lawsuits to cover medical costs, lost wages and other costs associated with cancer.

If you have developed cancer after taking Belviq, or noticed other side effects while taking it, you should also report your problems to the FDA’s MedWatch program. You can report online or download a form to mail in. You can also request a form at 1-800-332-1088.

Please seek the advice of a medical professional before making health care decisions.