What Happens If You Miss a Dose of Thyroid Hormone Medication?
Key takeaways:
Thyroid hormone medications help regulate your metabolism and keep your organs running smoothly when your body can’t make enough thyroid hormone on its own.
Taking your thyroid hormone medication regularly helps prevent symptoms of hypothyroidism. If you miss more than one dose, you may start to feel tired, cold, or achy.
A pill organizer or medication reminder app can help you remember to take your medication. Contact your prescriber if you miss a week or more.
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Table of contents
Your alarm didn’t go off this morning and you’re rushing out the door. In the chaos, you forgot to take your thyroid hormone medication. Now what?
If you can relate to this situation, you may be wondering what happens in your body when you miss one day or more of your thyroid medication. Let’s discuss why it’s so important to take your thyroid medication regularly — and review some tips that can help you do so.
What are thyroid hormone medications?
Thyroid hormone medications provide thyroid hormone when your body doesn’t have enough (hypothyroidism).
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Thyroid hormone plays an important role in growth and development. It also regulates your metabolism and body temperature. There are two main types of thyroid hormone: triiodothyronine (T3) and thyroxine (T4). T4 is the main form of thyroid hormone in your body. The liver and kidneys convert it into T3, which is considered the “active” form of thyroid hormone.
Prescription thyroid hormone medications contain T3, T4, or a combination of both. Some preparations are created in a lab while others are made from animal sources. Common thyroid hormone medications include:
Levothyroxine (Synthroid, Levoxyl, Tirosint, others) — lab-made T4
Liothyronine (Cytomel) — lab-made T3
Desiccated thyroid (Armour Thyroid, NP Thyroid) — a mix of T3 and T4 from animal sources
Tips for taking levothyroxine: These pharmacist-backed tips for taking thyroid hormone medications can help you get the most from your treatment.
Is your thyroid medication working? Here are some signs to look for to help you decide.
Armour thyroid vs. levothyroxine: Learn about the differences between these thyroid hormone medications to help you find the right fit for your needs.
Levothyroxine is the hypothyroidism medication that’s precribed the most, and it’s the first-choice medication for people with the condition.
Desiccated thyroid preparations are derived from the thyroid glands of animals (usually sheep, pigs, or cows). They aren’t prescribed as often as levothyroxine and they’re not FDA approved. One drawback of these medications is that the amount of thyroid hormone in each dose isn’t always the same.
Liothyronine is usually only prescribed when other thyroid medications aren’t working. It isn’t considered a first-choice treatment.
What happens if you forget to take your thyroid medication?
Your body needs a consistent amount of thyroid hormone to keep your cells and organs running smoothly. When you forget your medication, your hormone levels start to drop. How you feel will depend on how many doses of medication you miss.
If you miss 1 or 2 doses
Most thyroid hormone medications last in your body for several days. So if you take it every day and miss just one or two doses, you probably won’t feel any different.
If you miss a dose of your thyroid medication, take it as soon as you remember. If it’s almost time for your next dose, it’s usually fine to take two doses at once to make up for the one you missed. But you shouldn’t do this more than once without contacting your prescriber.
If you miss several doses
After missing several doses of your thyroid medication in a row, you may start to notice symptoms of low thyroid levels, such as:
Constipation
Feeling weak or tired
Muscle and joint pain
Weight gain
Sensitivity to cold
This is more likely if you’re taking liothyronine, as its levels in your body will drop significantly after 2 to 3 days. This may also apply if you’re only taking a thyroid hormone medication once or twice a week and miss one or two doses.
If you miss more than 2 days of your thyroid medication in a row, contact your healthcare team. They may want to make changes to your dose for a short time to get your hormone levels back to normal.
If you miss a week or more
Levothyroxine levels in the body start to drop significantly after about 6 or 7 days, so you’ll likely notice symptoms of hypothyroidism if you miss a week or more of the medication. If you’re taking a form of thyroid hormone that doesn't last in the body as long, the symptoms will be even more noticeable. If you don’t restart your medication, your levels will continue to drop and more severe symptoms are possible.
Reach out to a healthcare professional as soon as possible if you’ve missed a week or more of your thyroid medication. Seek emergency care if you notice swelling of your hands, feet, or face or if you’re feeling confused. These can be signs of a severe condition known as myxedema coma, which can happen as a result of untreated hypothyroidism.
Tips to help you remember to take your medication
Consider these tips if you’re having trouble remember to take your thyroid hormone medication:
Make it part of your routine. Have a set time in your normal routine to take your medication that’s the same every day. This helps make taking your medication a habit you’re less likely to forget.
Make your thyroid medication visible. It can be helpful to store your medications where you can see them. Just be sure to avoid areas with high humidity, such as the bathroom. Moisture, heat, and light can affect the integrity of medications. You should also make sure your medication is out of the reach of children and pets.
Find the time that works best for you. It’s recommended to take levothyroxine 30 to 60 minutes before breakfast, on an empty stomach. But if you’re having trouble remembering your thyroid medication in the morning, talk with your prescriber about taking it at bedtime instead. Studies have shown that taking levothyroxine at least 2 hours after your evening meal is just as effective as taking it before breakfast. What’s important is being consistent with when you take it.
Leave yourself reminders. You can put reminders in your home to help you remember to take your medication. Put it in a place where you’ll see it every day — like a sticky note on the bathroom mirror or the coffee pot.
Use technology. Your mobile phone can help you remember to take your medication. There are several medication reminder apps you can download on your smartphone. A daily alarm or calendar reminder can also do the trick.
Use weekly or monthly pill boxes. Pill boxes labeled with the days of the week are helpful for organizing your medications (especially if you take more than one). They also make it easy to see if you’ve missed a dose. There are even “smart” pill boxes that connect to an app on your phone to remind you to take your medications.
Set up automatic refills. The first step to taking your medication is making sure you don’t run out. Most pharmacies can set up your prescription to be automatically refilled when they’re due. Ask your pharmacist if this option is available to you.
If you’re still having trouble remembering your medication, talk to your healthcare team. They can work with you to find a solution that fits your needs.
Frequently asked questions
There isn’t a set amount of time you can go without taking your thyroid medication. Over time, low thyroid hormone levels can put you at risk of developing heart issues and mental health problems. In severe cases, untreated hypothyroidism can result in a condition known as myxedema coma, which can be life-threatening. So it’s best to talk to a healthcare professional if you’re having trouble taking your medication regularly or experiencing unwanted side effects.
Yes, stopping your thyroid medication without professional guidance can have serious consequences, including death. Thyroid hormone is essential to keep your body running properly. So it isn’t a good idea to stop taking levothyroxine unless your prescriber recommends it. If you’re concerned about side effects or other issues, talk to your healthcare team about other treatment options. They can address your concerns and ensure you’re getting the treatment you need.
The bottom line
Thyroid hormone medications, such as levothyroxine (Synthroid), replace thyroid hormone when your body doesn’t have enough. Most of these medications last in your body for several days. So missing one dose of your thyroid medication is usually not a big deal. But missing multiple doses can lead to hypothyroidism symptoms, such as feeling cold, tired, or constipated. And stopping your thyroid medication altogether can be dangerous to your health.
There are several ways to help yourself remember to take your thyroid medication. But if you’re still having trouble, talk to your healthcare team. You may need a different approach to make sure your thyroid hormone levels stay in a healthy range.
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References
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American Thyroid Association. (n.d.). Thyroid hormone treatment.
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PD-Rx Pharmaceuticals. (2024). Liothyronine sodium- liothyronine sodium tablet [package insert].
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