The drug Lorcaserin (or Belviq), which was approved by the United States Food and Drug Administration in 2012, has been shown to help people lose weight — and keep it off — without exacerbating heart problem risks in the process, according to a new study from researchers at Brigham and Women's Hospital in Boston.

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"Patients and their doctors have been nervous about using drugs to treat obesity and for good reason," study author Erin Bohula told the Associated Press. "There's a history of these drugs having serious complications."

The researchers tested the appetite suppressant in a study of 12,000 individuals who were either overweight or obese with high risk of heart disease. Half were given Belviq twice a day and the others received dummy pills. The individuals were also offered lifestyle and diet advice, and were followed for about three years after treatment.

Belviq's maker, Eisai Inc., sponsored the study and many of the researchers involved either consult or work for the company. The appetite suppressant works by stimulating brain chemicals to give a feeling of fullness and costs roughly $220 to $290 a month in the U.S.

The researchers published their findings Sunday in the New England Journal of Medicine after presenting them at the 2018 European Society of Cardiology Congress.

Here are some of the study’s key findings:

  • After 40 months, Belviq users shed 9 pounds, twice as much as those on dummy pills.
  • About 8.5 percent of those in the Belviq group developed diabetes, compared to 10.3 percent of those taking dummy pills.
  • Those on Belviq experienced more serious side effects — 7 percent versus 4 percent — and stopped taking their weight loss pills due to the dizziness, fatigue, nausea and headache.
  • Thirteen Belviq users suffered dangerously low blood sugar, compared to four in the dummy pill group.
  • There were no significant differences regarding heart valve damage.
  • Twenty-one people on Belviq reported having suicidal thoughts or behavior versus 11 people on dummy pills, but the Belviq users had a higher rate of history of depression.
  • After 3.3 years of follow-up, 6.1 percent of Belviq-treated individuals experienced a major cardiovascular event (death, heart attack, stroke) compared to 6.2 percent in the placebo group.

"We're so scared of the old drugs and valve damage," German researcher Stephan Achenbach, who chaired the European Society of Cardiology meeting in Munich on Sunday, told TCTMD.com. "That's what we all have in our minds. ... So this is a relief. This is a drug that is safe."

But Austrian doctor Kurt Huber, who was not involved in the research, questions whether the follow-up is sufficient.

“It’s safe for a bit more than 3 years,” he said, “but what happens when we double the length of treatment?”

At least for now, Belviq "may be best used on a cautious basis, according to the needs of individual patients," journal editors Julie Ingelfinger and Clifford Rosen wrote in an accompanying editorial.

Explore the full study at nejm.org.

The Associated Press contributed to this story.