How to Take Your Thyroid Medication

Ensuring Efficacy—and Safety

Taking your thyroid medication may, at first glance, seem fairly simple. Yet, whether you are treating hypothyroidism or hyperthyroidism, there are several things you need to know to ensure that the drug you are on works as it should and your symptoms are well-managed. This begins with checking your prescription when picking it up at the pharmacy and carries through to your daily routine, from when you take your medication to what you take your medication with and more.


3 Women Share Their Thyroidectomy Experiences

Taking your thyroid medication as intended not only ensures proper absorption but limits the risk of potentially harmful side effects.

tips for taking thyroid medication
Illustration by Emily Roberts, Verywell

Handling Your Prescription

Before you take a dose of any thyroid medication, there are several steps you should take to make sure you are getting the appropriate dose and that it will reach its target in the body.

Double-Checking Your Medication

When you first get your prescription, take a moment to look at both the label and the pills. It's surprising how often people receive the wrong medication or pills that have expired. Go through this checklist each and every time you get a refill.

  • Double-check that you are receiving the correct medication.
  • Confirm that you are getting the correct dosage.
  • Make sure that the medication is not expired.
  • Confirm that you have received the correct number of pills.
  • If you are not on a generic medication, check to see that you have not inadvertently received one as a substitute. While the different brands (and generics) of levothyroxine contain the same active medication, other ingredients can vary and may affect their absorption and more.


Once you get your medication home, make sure that you are properly storing your thyroid drugs. This means you should not store your medications in the bathroom or in a damp area. Also be sure that your medications are not exposed to heat for long periods.

Taking Your Medication for Hypothyroidism

Thyroid replacement therapy—levothyroxine, T4/T3 combination therapy, or a natural desiccated thyroid drug—works best when it is taken consistently and at the same time every day. It's also important to note that there are a number of foods, medications, supplements, and medical conditions that may decrease the chance that your body will receive the full dose.


The first step in effectively taking your medication is actually remembering to take your pills each day. Studies have shown that it's almost the norm for people to sometimes forget medications that are taken daily and missing even a day or two of your thyroid replacement can alter how well you feel.

It's suggested that people combine taking their medication with something else they do each day that doesn't involve food or drink, such as brushing their teeth in the morning, to increase the chance of remembering. If you're prone to forget, you may wish to set an alarm on your phone or think of some other creative way to remember your thyroid pills.

Dosing and Monitoring

When thyroid replacement is first prescribed, the dose may vary depending on your age and other factors. Thyroid tests are then checked every six weeks, with the dose usually increased in 25 to 50 microgram increments until your levels are stable. At that time, your healthcare provider will tell you how often you should be monitored from there on out.

Know, however, that the dose you require may change over time. If you develop heightened symptoms of hypothyroidism or new symptoms of hyperthyroidism, see your healthcare provider—even if you are not due for a visit.

Pregnancy Concerns

You should also see your healthcare provider right away if you become pregnant, as the dose of your medication will likely need to be increased. It is usually recommended that once you find out you are pregnant you can increase your dose by approximately 20%.

After delivery, it is safe to take your thyroid medication if you are breastfeeding, as only minimal amounts reach the baby through milk.

Switching Brands

For some people, switching brands of levothyroxine or changing to a generic can have a negative impact on how they feel, and many are surprised to learn that these substitutions can be made at the pharmacy without your healthcare provider knowing. If this is the case for you, you can have your healthcare provider write "dispense as written/no substitutions" on your prescription to make sure you receive the same product each month.

Not All Levothyroxine Is Equal

The amount of levothyroxine in a tablet can differ. For example, a 100 mcg tablet may contain between 95 mcg and 105 mcg of hormone.

Since the amount of levothyroxine is relatively stable within a brand name drug or generic manufacturer, this is primarily an issue for those who switch between different generic tablets.


With levothyroxine, many healthcare providers believe that taking the drug first thing in the morning (on an empty stomach) allows for the best absorption. After the medication is taken, avoid eating anything (even drinking coffee) for at least one hour. An exception may be Tirosint if you simply must have your coffee soon after you wake up.

There are some foods, medications, and common supplements that should be avoided for at least three hours after taking thyroid medication (see below).

In recent years, there has been some research to support taking thyroid medication at bedtime instead of in the morning to maximize absorption. A disadvantage is that this may keep some people awake, especially those who use combination T3/T4 therapy or desiccated thyroid. If this is of interest to you, talk to your healthcare provider.

Food Interactions

Food may affect the absorption of thyroid hormone by binding with it, decreasing access to absorption sites in the intestine, altering the rate at which it dissolves, or changing the stomach's pH balance.

Special attention should be given to the following:

  • High-calcium foods: Foods that are high in calcium, such as Greek yogurt or calcium-fortified orange juice, may reduce absorption if consumed within three hours of your thyroid medication.
  • High-fat diet/low-fat diet: A high-fat diet can interfere with the absorption of levothyroxine. This is usually not a problem if you have the same dietary patterns each day, but if you should change from a high-fat diet to a low-fat diet, you could potentially absorb more medication and end up overmedicated.
  • Fiber: The role of a high-fiber diet and thyroid absorption is still uncertain. If you change the amount of fiber in your diet (since a high-fiber diet can be healthy), you should have your TSH tested to make sure your levels are stable.
  • Goitrogenic foods: Goitrogenic foods (broccoli, cauliflower, strawberries, and others), while often very healthy and packed with powerful phytochemicals, can have antithyroid effects similar to antithyroid drugs. Eating these foods in moderation is fine (and good), but they should not be eaten in large quantities by people on thyroid hormone replacement therapy who still have a thyroid. Cooking may help minimize a food's goitrogenic potential.

Drug Interactions

There are several hundred drugs (both prescription and over-the-counter) that interact with thyroid medications, so it's important to check with your healthcare provider and pharmacist whenever you start a new medication. You can also double-check by searching the generic name to look for drugs that interact with thyroid hormone medications.

If your healthcare provider recommends one of these medications, it does not necessarily mean that you can't take it, but your TSH should be monitored carefully after you start.

Some of the more common drugs that interact with levothyroxine include:

  • Serotonin-reuptake inhibitors (SSRIs) often used for anxiety and depression, such as Zoloft (sertraline) and Celexa (citalopram): If you will be taking one of these drugs, the dose of your thyroid medication may need to be increased to be effective.
  • Proton pump inhibitors (PPIs), such as Prilosec (omeprazole), Prevacid (lansoprazole), and Nexium (esomeprazole): While helpful in treating conditions such as acid reflux and peptic ulcer disease, they can impair absorption of thyroid drugs.
  • Tricyclic antidepressants, such as Elavil (amitriptyline), Sinequan (doxepin), and Norpramin (desipramine): Unlike many interactions with thyroid drugs, this one can actually increase the potency of both drugs.
  • Diabetes medications: Both insulin and oral hypoglycemic drugs for diabetes can reduce the effectiveness of thyroid hormone, and thyroid medications can increase insulin requirements in people with diabetes. Blood glucose levels and TSH need to be closely monitored.
  • Birth control pills and hormone replacement therapy: Estrogen can increase the production of a protein that binds thyroid hormone and makes it inactive. Women who take estrogen may need to take a higher dose of thyroid medication.
  • Some cholesterol-lowering drugs, such as Questran (cholestyramine) and Colestid (colestipol), can bind to thyroid hormone, making it inactive. It's suggested that these drugs be taken at least four hours after taking thyroid hormones.
  • Anticoagulants (blood thinners), like Coumadin (warfarin) or Heparin: These can, on occasion, become stronger in the system when thyroid hormone is added to the mix. The combination can increase your risk of bleeding.
  • Antacids: It's usually recommended that antacids (such as Tums or Mylanta) be taken at least three to four hours after thyroid hormones.

There are many other drugs that may interfere with thyroid hormones. Some others that cause very significant interactions include Welchol (colesevelam) for heart disease, Renagel (sevelamer) and Fosrenol (lanthanum) for people with high phosphorus levels due to kidney disease, Fosrenol (lanthanum), and the antibiotic Cipro (ciprofloxacin).

The above is NOT a complete list of all drugs that can interact with thyroid medicines. Talk to your pharmacist or healthcare provider for more information.

Supplement Interactions

Many dietary supplements that can bind with or interfere with the absorption of thyroid hormones, increase the absorption, or affect thyroid testing.

Some of the more common ones include:

  • Calcium: Calcium tablets, whether calcium citrate, acetate, or carbonate, should be taken at least three hours after thyroid hormones.
  • Iron: Iron can bind with thyroid hormones creating an iron-levothyroxine complex that prevents the hormone from working. Whether you take iron alone, or as part of a multivitamin or prenatal vitamin supplement, you should wait at least two hours after taking your thyroid medication.
  • Biotin: Biotin does not significantly affect absorption if taken at least an hour after thyroid hormones, but it can interfere with thyroid testing and cause abnormal results. Biotin may be purchased alone, but is also an ingredient in many supplements.
  • Vitamin C: Vitamin C may actually increase the absorption of thyroid hormone and could lead to symptoms of hyperthyroidism.
  • Iodine or kelp: While iodine or kelp supplements (which are high in iodine) may be helpful to thyroid patients in parts of the world where iodine deficiency is a cause of thyroid disease and goiters, this is not really the case in the United States and other developed countries where iodine is added to table salt and food products. In fact, in these places, most cases have nothing to do with iodine deficiency at all. Your thyroid is extremely sensitive to iodine, so adding too much to your diet can irritate and aggravate the gland.

If you are taking any supplements, it's important to look at the individual ingredients to determine if interactions may exist and to tell your healthcare provider about whatever you are taking (or plan to take).

Medical Conditions That Affect Absorption

There are a number of medical conditions that may affect the absorption of thyroid medications, and, hence, the effectiveness of a particular dose. Some of these include:

  • Lactose intolerance
  • Celiac disease
  • Atrophic gastritis
  • Malabsorption syndromes
  • Helicobacter pylori infection
  • Autoimmune gastritis
  • Pancreatic diseases
  • Liver disease

Gene differences (polymorphisms) may also result in decreased effectiveness in some people, such as those who have polymorphisms in iodothyronine deiodinase 2.

For people with health conditions that affect digestion such as inflammatory bowel disease (Crohn's disease or ulcerative colitis), or celiac disease, the Tirosint brand of levothyroxine with fewer ingredients that may be better tolerated. In addition, the liquid or gel cap form of levothyroxine may be better absorbed than levothyroxine pills.

If you have any of these conditions, it will be important to have your thyroid tested regularly.

Potential Allergies

While allergies to levothyroxine are uncommon, allergic reactions or sensitivities to the inactive ingredients in thyroid medications may occur. In addition to levothyroxine, the Synthroid brand contain acacia (which can cause allergies in some people with tree or grass allergies), lactose (that can be a problem for people with lactose intolerance), and cornstarch (that can affect people who have corn allergy and may cross-react to affect some people with gluten sensitivity).

Oral vs. Sublingual Delivery

With natural desiccated thyroid medications only, some people have argued that allowing the medication to dissolve under the tongue (either whole or crushed) may result in faster absorption into the bloodstream. The counterargument is that these molecules are large and most will be absorbed through the intestine anyway, so taking the medication sublingually could result in irregular absorption.

The bottom line is that if you are considering taking your medication this way, talk to your healthcare provider and make sure your thyroid levels are monitored.

Taking Your Medication for Hyperthyroidism

There are some similar but distinct considerations if you are taking medication for hyperthyroidism.

Forgetting Your Medication

If you do forget your medication, do not take your dose late or double up if you are taking the natural thyroid medications that have T3 in them like Armour and Nature Thyroid. Doing so can result in symptoms of an overdose, such as nausea and vomiting and more. It's especially important to come up with creative ways to remember taking your hyperthyroid medication since both Tapazole (methimazole or MMI) and PTU (propylthiouracil) are usually taken three times daily. If you are taking levothyroxine, however, and forget it for one day, you can take two pills the next day.

Medication Interactions

There are many drugs that can interact with hyperthyroid medications, and it's important to talk to your endocrinologist before you take any new medications. Common interactions include drugs such as:

  • Digoxin (for heart problems)
  • Blood thinners (such as Coumadin or warfarin)
  • Beta-blockers, such as Tenormin (atenolol)

Caution also needs to be taken when using over-the-counter cold medications or any medications that have a stimulant effect.

Adverse Reactions

Serious adverse reactions may occur for some people taking anti-thyroid drugs, and it's important to be on the lookout for potential symptoms. Unlike medications for hypothyroidism that are essentially replacing hormones your body is no longer making, anti-thyroid medications carry a greater risk of side effects and adverse reactions.

The most common ones include:

  • Liver toxicity: Signs of liver toxicity include abdominal pain, dark urine, jaundice (a yellowish discoloration of the skin and the whites of the eyes), and clay-colored stools.
  • Agranulocytosis (a low level of white blood cells): Symptoms may include a fever and other signs of infection, such as a sore throat, cough, pain with urination, and headache.

If you are taking anti-thyroid medications, it's important to avoid close contact with people who are ill and to stay up-to-date on immunizations.


If you learn you are pregnant or believe you may be while taking Tapazole (methimazole or MMI), stop your medication and contact your healthcare provider immediately.

A Word From Verywell

In order to get the full benefit from your thyroid medication, it's important to take the steps outlined above to make sure you are actually taking the right drug and that it reaches your bloodstream where it can do its job.

If you don't feel like your thyroid medication is working, reassess how you are taking the drug and if there could be interactions. For those who are hypothyroid and on levothyroxine alone, adding a T3 medication may sometimes help. For others, switching to natural desiccated thyroid drugs may be an option.

Frequently Asked Questions

  • What drugs are used to treat hypothyroidism?

    Hypothyroidism (low thyroid function) is treated with one or more of the following thyroid hormone replacement drugs:

  • What drugs are used to treat hyperthyroidism?

    Hyperthyroidism (overactive thyroid) is treated with antithyroid drugs that block the production of the thyroid hormones T3 and T4, namely:

    • Tapazole (methimazole)
    • Propylthiouracil (PTU)
  • Are thyroid replacement hormones taken with or without food?

    Levothyroxine should be taken on an empty stomach, while liothyronine can be taken with or without food. Avoid taking the drugs within three hours of consuming high-calcium foods as the drugs' absorption may be reduced. Soybeans, walnuts, and dietary fiber may also need to be avoided.

  • How do you give hypothyroid drugs to children?

    For children or adults who cannot swallow tablets, crush and mix levothyroxine or liothyronine with 1 to 2 teaspoons of water. Do not mix with food or soybean-based infant formula. Give this mixture by spoon or dropper right away.

  • What drugs interact with thyroid replacement hormones?

    A number of drugs can interfere with the absorption of thyroid replacement hormones, most specifically antacids, calcium supplements, cholesterol-lowering drugs, and iron supplements. Let your healthcare provider know about any medications you take before starting levothyroxine or liothyronine.

  • Are hyperthyroid drugs taken with or without food?

    Both Tapazole (methimazole) and propylthiouracil (PTU) can be taken with or without food. With that said, taking Tapazole with food or milk can reduce the risk of an upset stomach.

  • What drugs can interact with hyperthyroid drugs?

    Both Tapazole (methimazole) and propylthiouracil (PTU) can interact with beta-blockers, digitalis, theophylline, and blood thinners like warfarin. The interactions can usually be mitigated by reducing the dose of the accompanying drug.

Was this page helpful?
Article 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. Dayan C, Panicker V. Management of hypothyroidism with combination thyroxine (T4) and triiodothyronine (T3) hormone replacement in clinical practice: a review of suggested guidance. Thyroid Res. 2018;11:1. doi:10.1186/s13044-018-0045-x

  2. Garber J, Cobin R, Gharib G, et al. Clinical practice guidelines for hypothyroidism in adults: cosponsored by the American Association of Clinical Endocrinologists and the American Thyroid AssociationThyroid. 2012;22(12):1200-35. doi:10.1089/thy.2012.0205

  3. American Thyroid Association, "Q and A: Thyroxine Preparations"

  4. Samarasinghe, S., Meah, F., Singh, V. et al. Biotin Interference with Routine Clinical Immunoassays: Understand the Causes and Mitigate the Risks. Endocrine Practice. 2017. 23(8):989-998.

  5. Skelin, M., Lucijanic, T., Amidzic Karic, D. et al. Factors Affecting Gastrointestinal Absorption of Levothyroxine: A Review. Clinical Therapeutics. 2017. 39(2):378-403. DOI:


  6. Johns Hopkins Lupus Center, "Thyroid Medications"

  7. Pirola I, Formenti AM, Gandossi E, et al. Oral liquid L-thyroxine (L-t4) may be better absorbed compared to L-T4 tablets following bariatric surgery. Obes Surg. 2013;23(9):1493–1496. doi: 10.1007/s11695-013-1015-y

  8. MedlinePlus. Hyperthyroidism. Updated April 2, 2021.

  9. MedlinePlus. Levothyroxine. Updated February 15, 2019.

  10. MedlinePlus. Liothyronine. Updated January 15, 2018.

  11. Kavanaugh S, Boparai P. Thyroid dysfunction and drug interactions. Pharma J. 2015 Jun;294(7685):20068601.

  12. MedlinePlus. Methimazole. Updated July 15, 2017.