• Anxiety

  • Breast enlargement in men (possible)

  • Difficulty concentrating

  • Double vision

  • Eyeballs that stick out (exophthalmos)

  • Eye irritation and tearing

  • Fatigue

  • Frequent bowel movements

  • Goiter (possible)

  • Heat intolerance

  • Increased appetite

  • Increased sweating

  • Insomnia

  • Menstrual irregularities in women

  • Muscle weakness

  • Nervousness

  • Rapid or irregular heartbeat (palpitations or arrhythmia)

  • Restlessness and difficulty sleeping

  • Shortness of breath with exertion

  • Tremor

  • Weight loss (rarely, weight gain)