Tell your doctor immediately if any of these signs of too much thyroid hormone occur: diarrhea, headache, heat intolerance, irritability, menstrual changes, nervousness, trouble sleeping, heavy sweating, unusual weight loss. Tell your doctor immediately if any of these rare but very serious side effects occur: irregular/pounding heartbeat, trouble breathing with exercise, swelling of the arms/legs, extreme weakness. Seek immediate medical attention if any of these rare but very serious side effects occur: chest/jaw/left arm pain.A very serious allergic reaction to this drug is unlikely, but seek immediate medical attention if it occurs. Symptoms of a serious allergic reaction may include: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing. This is not a complete list of possible side effects.
Thyroid hormone should not be used either alone or in combination with diet pills to treat obesity/cause weight loss in patients with normal thyroid production. If used in combination with diet pills (appetite-suppressant drugs), serious, even life-threatening effects could occur.