Treating Hypothyroidism

Hypothyroidism is easy to treat with medicine that boosts your low levels of thyroid hormone. It's not a cure, but it can keep your condition under control for the rest of your life.

The main treatment is levothyroxine (Euthyrox, Levothroid, Levoxyl, Synthroid, Unithroid), a man-made version of the thyroid hormone thyroxine (T4). It acts just like the hormone your thyroid gland normally makes. With the right dose, you can improve or get rid of symptoms like weight gain, fatigue, and depressed mood caused by an underactive thyroid gland.

Starting on Thyroid Hormone Treatment

Your doctor will decide how much thyroid hormone to give you based on your:

  • Age
  • Health
  • Thyroid hormone levels
  • Weight

If you're older or you have heart disease, you may start on a small dose. Then your doctor will slowly raise the amount over time until you see an effect.

About 6 weeks after you start taking the medicine, you'll go back to your doctor for a blood test to check your thyroid hormone levels. The dose may need to be raised or lowered based on the results. Once they’re stable, you'll see your doctor for a blood test every 6 months to a year.

How to Take Your Medicine

To make sure your hypothyroidism stays under control:

Stick with the same brand. Different types of thyroid hormone medicine may contain slightly different doses, which could affect your hormone levels.

Follow a schedule. Take it at the same time each day. Shoot for about an hour before a meal or at bedtime. Don't take it when you eat, because food can affect the way your body uses it.

Don't skip doses. If you miss one, take it as soon as you remember. You can take two pills in one day if you need to.

Follow instructions carefully. Don't stop taking your medicine without first checking with your doctor.

When Your Symptoms Don't Go Away

You should start to feel better a few days after you begin taking medicine. But it may take a few months for your thyroid hormone levels to get back to normal.

If it raises your levels but you still have symptoms like fatigue and weight gain, your doctor may need to change your treatment. She may prescribe something that contains both T4 and a more active form of thyroid hormone called T3, sold as desiccated thyroid extract (Armour Thyroid, Thyrar) or liotrix (Thyrolar). However, T3 treatment is not common.


Side Effects

The main risk of thyroid medicine is if you take too much of it, you can get symptoms of an overactive thyroid, like:

  • Fast heartbeat
  • Sensitivity to heat
  • Hunger
  • Nervousness and anxiety
  • Shakiness
  • Sweating
  • Thin skin and brittle hair
  • Tiredness
  • Trouble sleeping
  • Weight loss

If you have any of these symptoms, see your doctor for a blood test. You may need a lower dose of thyroid medicine.

Drugs That Interact With Thyroid Medicine

Some medicines can affect the way your thyroid drug works, including:

  • Anti-seizure medicines like carbamazepine (Tegretol) and phenytoin sodium (Dilantin)
  • Birth control pills and estrogen
  • Cancer drugs called tyrosine kinase inhibitors
  • Medicines for depression, like sertraline (Zoloft)
  • Testosterone

If you take one of these medicines, ask your doctor whether you need to change your dose of thyroid medicine.

Stick With Treatment

You'll need to keep taking thyroid medicine throughout your life to control your hormone levels. Keep up with your treatment, and you'll see results. You'll feel better, and your levels won't drop again.

WebMD Medical Reference Reviewed by Minesh Khatri, MD on November 14, 2016



American Thyroid Association: "Hypothyroidism," "Thyroid Hormone Treatment."

FDA: "Thyroid Medications: Q & A with Mary Parks, MD."

Garber, J. Thyroid, November-December 2012.

Jonklaas, J. Thyroid, September 2014.

Medscape: "Hypothyroidism."

National Endocrine and Metabolic Diseases Information Service: "Hypothyroidism."

© 2015 WebMD, LLC. All rights reserved.