Take levothyroxine exactly as it was prescribed for you. Follow all directions on your prescription label and read all medication guides or instruction sheets. Your doctor may occasionally change your dose.
Levothyroxine oral is taken by mouth. The injection is given as an infusion into a vein. Levothyroxine is usually given by injection only if you are unable to take the medicine by mouth.
Levothyroxine oral works best if you take it on an empty stomach, 30 to 60 minutes before breakfast. Follow your doctor's dosing instructions and try to take the medicine at the same time each day.
Swallow the tablet or capsule whole, with a full glass (8 ounces) of water. The tablet may dissolve very quickly and could swell in your throat.
Measure liquid medicine carefully. Use the dosing syringe provided, or use a medicine dose-measuring device (not a kitchen spoon).
Levothyroxine doses are based on weight in children. Your child's dose needs may change if the child gains or loses weight.
It may take several weeks before your body starts to respond to levothyroxine. Keep using this medicine even if you feel well. You may need to use this medicine for the rest of your life.
You may need frequent medical tests. Tell any doctor, dentist, or surgeon who treats you that you are using this medicine.
Store at room temperature away from moisture and heat.
Do not share this medicine with another person, even if they have the same symptoms you have.
 Detailed Levothyroxine dosage information
What happens if I miss a dose?
Take the medicine as soon as you can, but skip the missed dose if it is almost time for your next dose. Do not take two doses at one time.
What happens if I overdose?
Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.
Overdose symptoms may include headache, leg cramps, tremors, feeling nervous or irritable, chest pain, shortness of breath, and fast or pounding heartbeats.
