Although it certainly works wonderfully as a weightloss pill, Meridia™ has some quite irritating side effects; side effects frequently reported are insomnia/sleeping problem, constipation, upset stomach, dizziness, drowsiness, menstrual pain, headache, flushing, muscle/joint pain, and some more. Few but worth mentioning sides: cardiac arrhythmias (irregular heartbeat), moody (extreme mood change from excitement down to thought of suicide) and the feel of tingling, pricking, or numbness of a person's skin. Also problems urinating, seizures, jaundice, fever, abnormal vision, and more other. Even some reports of heart failure, renal failure and sudden death have been filed.