Common side effects of Levothyroxine are include:
Feeling sick. Stick to simple meals and do not eat rich or spicy food.
Being sick (vomiting) or diarrhoea. Drink plenty of water to prevent dehydration. ...
Headaches. ...
Feeling restless or excitable, or problems sleeping. ...
Flushing or sweating. ...
Muscle cramps. ...
Shaking, usually of the hands.