Nausea, dry mouth, headache, dizziness, constipation, or tiredness may occur. If any of these effects last or get worse, tell your doctor or pharmacist promptly.

Remember that this medication has been prescribed because your doctor has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.

Tell your doctor right away if you have any serious side effects, including: easy bleeding/bruising, enlarged breasts or abnormal breast milk production, mental/mood changes (such as confusion, depression, thoughts of suicide, unusual agitation, difficulty with attention/memory), shaking/twitching muscles, shortness of breath, slow/fast/irregular heartbeat, swelling ankles/feet/hands, unexplained fever.

If you are taking medication to treat diabetes, lorcaserin can increase your risk for low blood sugar (hypoglycemia). Symptoms of low blood sugar include sudden sweating, shaking, fast heartbeat, hunger, blurred vision, dizziness, or tingling hands/feet. Tell your doctor right away about the reaction and the use of this product. Your doctor may need to adjust your medication(s).

Rarely, males may have a painful or prolonged erection lasting 4 or more hours. If this occurs, stop using this drug and get medical help right away, or permanent problems could occur.

A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing.

This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.

In the US -

Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or at www.fda.gov/medwatch.

In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.