Lorcaserin Side Effects

Common Side Effects

Lorcaserin has been studied extensively in clinical trials. In these studies, one group of people received the real medication, while another group received a placebo (a "sugar pill" that does not contain any active ingredients). As a result, it was possible to see what side effects occurred, how often they appeared, and how they compared to the placebo.
In these studies, the most common side effects of lorcaserin included:
  • Low blood sugar levels (hypoglycemia) in people with diabetes -- in up to 29.3 percent of people
  • Headache -- up to 16.8 percent
  • An upper respiratory tract infection -- up to 13.7 percent
  • Symptoms of the common cold -- up to 13 percent
  • Back pain -- up to 11.7 percent
  • Nausea -- up to 9.4 percent
  • Urinary tract infection (UTI, such as a bladder infection) -- up to 9 percent
  • Dizziness -- up to 8.5 percent
  • Cough -- up to 8.2 percent
  • Fatigue -- up to 7.4 percent
  • Diarrhea -- up to 6.5 percent
  • Constipation -- up to 5.8 percent.
Other common side effects, occurring in 2 percent to 5.8 percent of people, included:
Last reviewed by: Kristi Monson, PharmD
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