Is There a Best Time to Take Your Thyroid Medication?

If you have an underactive thyroid gland, you need to take your medication every day at the same time.

Doctors often tell you to take your thyroid medication first thing in the morning. There is some research, though, that suggests it may be better to take your dose at bedtime. This may be because it's easier for your body to absorb thyroid hormone overnight.

For most people, it doesn't really matter if you take your thyroid medicine in the morning or just before bed. The choice is really just a matter of what suits your lifestyle best.

Talk to your doctor about when to take your thyroid medication. The information here can help guide your conversation.

This article discusses some of the pros and cons of taking thyroid medication at different times of the day.

Thyroid Disease Healthcare Provider Discussion Guide

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Taking Thyroid Medication in the Morning

The most common thyroid hormone replacement medication is levothyroxine. This drug is a synthetic form of the thyroid hormone thyroxine. Thyroxine is also called T4.

In your body, T4 is converted into another hormone called triiodothyronine. This hormone is also called T3. It regulates many of your body's functions. 

Experts have long recommended taking thyroid medication like levothyroxine first thing in the morning. Typically, you're told to take your medication with water and wait at least an hour before breakfast or coffee.

Experts also recommend waiting three or four hours before taking other medications or supplements. This helps make sure your thyroid medication is absorbed by your body.

Pros

Taking your thyroid medication in the morning may be what you've always done. It's important to be consistent with your medication. For this reason, it may not make sense to switch to taking your medication at night.

An exception is if your doctor is concerned about how well you're absorbing your medication. Another reason might be because you're taking another medication or supplement that could interact with your thyroid medication.

These problems may show up in your thyroid stimulating hormone (TSH) blood test. TSH is the hormone that tells your body to make thyroid hormones.

Cons

Some people think taking levothyroxine in the morning is inconvenient. Reasons may include:

  • They don't want to wait an hour before eating or drinking coffee.
  • They need to take other medications or supplements in the morning. Calcium and iron supplements are examples. These supplements can interfere with a thyroid drug's absorption.

Recap

You may want to keep taking your thyroid medication in the morning because you have always done it that way. Some people, though, find it inconvenient. It may also interfere with other medications and supplements that have to be taken in the morning.

when to take levothyroxine thyroid medication

Verywell / Emily Roberts

Taking Thyroid Medication at Night

If you are going to take your thyroid medication at night, experts suggest waiting until three or four hours after your last meal or snack.

Pros

Taking your medication at night may have some benefits, including:

  • You don’t have to worry about when to eat breakfast.
  • It may be easier to avoid things that can interfere with thyroid medication absorption. This may include calcium, iron, and high-fiber foods.
  • Coffee drinkers don't have to wait until an hour after their medication to enjoy their first cup.
  • Research suggests that levothyroxine may be better absorbed at night.

A 2020 review looked at a number of studies that compared morning doses of thyroid medication to nighttime doses. The authors found that patients who took their medication at bedtime had a significant increase in their levels of free T4. Free T4 is the active form of the T4 hormone.

There are a few different theories about why this might happen:

  • Breakfast foods may interfere with the absorption of thyroid medication.
  • A one-hour wait before breakfast may not be long enough.
  • Your bowels don't work as quickly at night. This means it takes longer for your medication to go through your intestines. The increased time may allow your body to absorb the medication better.
  • The conversion process of T4 to T3 may just work better in the evening.

Cons

Some people may find it challenging to take thyroid medication at night. Reasons may include:

  • It can be easy to forget to take your medication when you are tired.
  • You may not go to bed at the same time every day.
  • You may like to snack before bed.
  • Some thyroid drugs are stimulating. Examples include drugs that contain T3, such as Cytomel (liothyronine), and the drugs Nature-throid and Armour Thyroid (thyroid desiccated). Taking these drugs just before bed may make it hard to sleep.

Recap

There is some evidence that taking your medication at night may help your body absorb it. A nighttime dose may also fit your schedule better. On the other hand, if you don't go to bed at the same time every night or you take a thyroid medication that is stimulating, a nighttime dose may not work for you.  

Summary

Doctors have long recommended taking thyroid medication in the morning. Research suggests that this may not be necessary, though.

If you're used to taking your medication in the morning, there isn't much reason to change. An exception is if your doctor is concerned about medication absorption. 

Some people find it inconvenient to take thyroid medication in the morning. It may also be a problem if you have to take other drugs or supplements at the same time.

Your body may absorb your thyroid medication better if you take it at night. It may also be more convenient for you. On the other hand, it may not be a good strategy if you don't always go to bed at the same time or if your medication interferes with your sleep.

A Word From Verywell

In the end, the key is to be consistent. Take your thyroid medication around the same time and in the same way every day.

If you and your doctor decide to change the timing of your medication, it's important to monitor your progress. Have your thyroid levels checked about six to eight weeks after you make the switch.

Frequently Asked Questions

  • What can happen if I eat right after taking my thyroid medications?

    Your body won't able to absorb enough medication. Studies show that taking levothyroxine too soon before or after a meal or snack can lower absorption of the drug by about 20%.

  • How long does it take for thyroid medication to work?

    Your symptoms—fatigue, constipation, dry skin, brittle nails, and so forth—should get better within a few days. However, it will take four to eight weeks for your TSH blood levels to improve. Your endocrinologist will likely test your blood six to eight weeks after starting treatment or changing your dose.

  • What foods can interfere with thyroid medication?

    Dairy products and coffee have both been found to reduce the absorption of levothyroxine. Other foods that may interfere with thyroid medication include:

    • Soybeans
    • Walnuts
    • High-fiber foods

    Grapefruit and grapefruit juice may also be problematic.

9 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Pang X, Pu T, Xu L, Sun R. Effect of l‐thyroxine administration before breakfast vs at bedtime on hypothyroidism: A meta‐analysis. Clin Endocrinol. 2020;92(5):475-81. doi:10.1111/cen.14172 

  2. Ianiro G, Mangiola F, Di Rienzo TA, et al. Levothyroxine absorption in health and disease, and new therapeutic perspectives. Eur Rev Med Pharmacol Sci. 2014;18(4):451-6. doi:10.1016/j.clinthera.2017.01.005

  3. Rajput R, Chatterjee S, Rajput M. Can levothyroxine be taken as evening dose? Comparative evaluation of morning versus evening dose of levothyroxine in treatment of hypothyroidismJ Thyroid Res. 2011;2011:505239. doi:10.4061/2011/505239

  4. Pfizer. Cytomel (liothyronine sodium).

  5. Jonklaas J, Bianco AC, Bauer AJ, et al. Guidelines for the treatment of hypothyroidism: prepared by the American Thyroid Association task force on thyroid hormone replacementThyroid. 2014;24(12):1670-1751. doi:10.1089/thy.2014.0028

  6. National Institute for Diabetes and Digestive and Kidney Diseases. Hypothyroidism (underactive thyroid).

  7. Chon DA, Reisman T, Weinreb JE, et al. Concurrent milk ingestion decreases absorption of levothyroxineThyroid. 2018;28(4):454-457. doi:10.1089/thy.2017.0428

  8. Wiesner A, Gajewska D, Paśko P. Levothyroxine interactions with food and dietary supplements–a systematic review. Pharmaceuticals. 2021;14(3):206. doi:10.3390/ph14030206

  9. MedlinePlus. Levothyroxine.

By Mary Shomon
Mary Shomon is a writer and hormonal health and thyroid advocate. She is the author of "The Thyroid Diet Revolution."