Written by Austin Ulrich, PharmD, BCACP | Reviewed by Joshua Murdock, PharmD, BCBBS
Key takeaways:
Thyroid medications like levothyroxine (Synthroid) are used to treat low thyroid levels (hypothyroidism).
If you have borderline hypothyroidism, you may be able to stop your thyroid medication after some time. But those with more obvious hypothyroidism often need thyroid medications long term.
Talk to your healthcare provider before making any changes to your thyroid medications. This can help you avoid serious health problems and symptoms of hypothyroidism.
Cropped close-up shot of a woman’s enlarged thyroid.
Credit: sasirin pamai/iStock via Getty Images
If you have a low level of thyroid hormones in your body, you might have hypothyroidism. Hypothyroidism is a medical condition that can occur when your thyroid gland is underactive or doesn’t work as well as it should.
If you’ve been diagnosed with hypothyroidism, your healthcare provider might prescribe medication to replace the missing thyroid hormones. The most common medication used to treat hypothyroidism is levothyroxine (Synthroid, Levoxyl, Tirosint). In fact, levothyroxine is one of the most commonly prescribed medications in the U.S.
It’s important to take levothyroxine and other thyroid medications exactly as prescribed. These medications help your body function properly. If you stop taking them abruptly, you could develop certain health problems. It’s important to talk to your healthcare provider before stopping your thyroid medication.
In this article, we’ll review how thyroid medications work and what can happen if you stop taking them.
What is levothyroxine used for and how does it work?
Levothyroxine and some other thyroid medications are used to treat hypothyroidism. Before we talk about thyroid medications, let’s discuss how the thyroid gland works under normal conditions.
Your thyroid gland is a butterfly-shaped organ in your neck. It produces thyroid hormones that help your body run properly. The two main hormones made by the thyroid are thyroxine (T4) and triiodothyronine (T3). The pituitary gland produces a third hormone — thyroid stimulating hormone (TSH). It also tells your thyroid how much T3 and T4 to make.
These hormones help regulate many important body functions. These include functions like maintaining metabolism and body temperature. In fact, these hormones are involved in the healthy functioning of almost every organ in the body.
In hypothyroidism, your body doesn’t have enough thyroid hormone. Hypothyroidism can cause a wide variety of symptoms. These include symptoms like fatigue, weight gain, and depression. By replacing the missing thyroid hormone in your body, thyroid medications can help relieve these types of symptoms.
What are the different types of thyroid medications?
There are two main categories of hypothyroidism medications:
Synthetic thyroid medications: Levothyroxine is the most common synthetic thyroid medication. It’s a lab-made version of the T4 hormone. Levothyroxine has several brand-name products available, including Synthroid, Levoxyl, and Tirosint. A synthetic version of the T3 hormone is also available. It’s called liothyronine (Cytomel).
Natural thyroid products: These include desiccated thyroid products. They come from dried animal thyroid glands (usually pigs). These products — including Armour Thyroid and NP Thyroid — naturally contain T3 and T4 hormones. These products aren’t approved by the FDA, but they’re still available by prescription only. There aren’t as many studies on these products as there are for levothyroxine. They may also cause more side effects.
According to the American Thyroid Association, levothyroxine is the first-choice medication to treat hypothyroidism for most people.
What can happen if I stop taking my thyroid medication?
If you stop your thyroid medication abruptly, symptoms of hypothyroidism will likely return.
If hypothyroidism is left untreated, it can lead to serious health problems. You may experience mood swings, irritability, and slowed thoughts. In fact, hypothyroidism is one of the reversible causes of dementia.
Hypothyroidism can also damage your nerves, raise your risk of heart problems, and affect your fertility. And hypothyroidism is especially dangerous if you’re pregnant. It can cause risks to both the pregnant mother and baby.
Severe hypothyroidism can be life-threatening. In rare cases, your body could slow down so much that you enter a coma. This can even lead to death.
Is it possible to stop taking my thyroid medication in a safe way?
Yes, it’s possible. But you should always check with your healthcare provider first. Whether you’re able to safely stop taking thyroid medication may depend on the reason you are taking it.
Research shows that some people can safely stop taking thyroid medications. In a review of over 17 individual studies, up to one-third of people were able to stop their thyroid medication. But this was mostly in people with “borderline” hypothyroidism, also called subclinical hypothyroidism. In subclinical hypothyroidism, T4 levels are normal. People with this condition sometimes don’t even need thyroid medications at all.
Those who have clearer hypothyroidism may not be able to stop levothyroxine. Stopping levothyroxine usually leads to the return of hypothyroidism symptoms. In the review mentioned above, only about 12% of people with overt hypothyroidism were able to stop their thyroid medications successfully.
If you’ve had your thyroid completely removed, you’ll need thyroid medications for life. These medications will help your body function normally. If your thyroid was removed due to cancer, treatment may also lower the risk of your cancer coming back.
Talk to your healthcare provider before making changes to your thyroid medication. They can help make sure that you’re making the best decision for your health.
What happens if I miss a dose of thyroid medication?
If you miss a dose of thyroid medication, take it as soon as you remember. It’s possible to experience symptoms of hypothyroidism (like fatigue) after a missed dose. If you experience any symptoms, call your healthcare provider.
If you miss a dose and it’s almost time for your next dose, skip the missed dose. Take your next dose at your regularly scheduled time. It’s usually not advised to take two doses of thyroid medication at the same time. Too much thyroid medication can cause symptoms like shakiness, sweating, and fast heartbeat.
But if you forget to take your medication for several days, let your healthcare provider know. They may want to adjust your dose for a few days.
The bottom line
Thyroid medications like levothyroxine can help treat hypothyroidism. If you’re interested in stopping your medication, talk to your healthcare provider first. They can help you decide if this is a safe option for you. Many people with overt hypothyroidism can’t stop their thyroid medications without symptoms of hypothyroidism returning. And people who have had their thyroid completely removed will need thyroid medications for life.
Missing doses of thyroid medication can cause hypothyroidism symptoms to return. Taking your medication as prescribed can help avoid this. If you miss multiple doses of your thyroid medication, call your healthcare provider. They can let you know if your dose should be adjusted.
References
American Cancer Society. (2019). Thyroid hormone therapy.
Burgos, N., et al. (2021). Clinical outcomes after discontinuation of thyroid hormone replacement: A systematic review and meta-analysis. Thyroid.
Leave a Reply