Side Effects of Stopping Thyroid Medication

The consequences can be serious

If you have thyroid disease, stopping thyroid medications can cause an array of adverse symptoms such as fatigue, hair loss, changes in blood pressure, heart palpitations, and increases or decreases in weight.

The bigger concern is that the discontinuation of drugs like Synthroid (levothyroxine) places you at an increased risk of blood clots, infertility, and even coma if you have uncontrolled hypothyroidism (low thyroid function). If you have hyperthyroidism (overactive thyroid), the lack of treatment can lead to vision problems as well as an increased risk of heart attack and stroke.

While people who have borderline cases may be able to stop treatment, this should only be done under the direction of a healthcare provider.

This article describes the risks of stopping medications used to treat hypothyroidism or hyperthyroidism. It also explores the risks of untreated disease and whether can you die if you stop taking levothyroxine or other thyroid drugs.

risks of not taking thyroid medication
Verywell / Emily Roberts

How Is Thyroid Disease Treated?

Medications are a major part of the treatment of hypothyroidism and hyperthyroidism.

With hypothyroidism, the medications used are synthetic versions of the thyroid hormones that the body needs to function, known as:

With hyperthyroidism, two antithyroid drugs are used to tamp down the overproduction of T3 and T4 by the thyroid gland:

Side Effects of Stopping Thyroid Medication

If you have hypothyroidism—whether due to Hashimoto's disease, thyroid surgery, congenital hypothyroidism, or Graves' disease treatment—you shouldn't suddenly stop taking levothyroxine or other thyroid hormones without speaking with your healthcare provider first.

Stopping these hormones for even a week may cause side effects. Stopping them for a long time when the disease is uncontrolled can pose many health risks, including:

  • Changes in blood pressure
  • High cholesterol
  • Low body temperature
  • Fatigue
  • Muscle weakness
  • Joint pain
  • Depression
  • Memory problems
  • Weight gain
  • Infertility or birth complications
  • Irregular periods
  • Reduced sex drive
  • Constipation
  • Hair loss
  • Swollen hands, feet, and face
  • Increased risk of infection
  • Increased risk of heart disease

If you lack thyroid hormone for a very long period of time, you risk a dangerous condition called myxedema coma. This develops when your body’s functions slow to a point where life systems are compromised. Myxedema coma requires emergency medical treatment.

How Long Can You Go Without Thyroid Medication?

The drug half-life of levothyroxine is six to seven days, which means it takes about four to five weeks for your body to be completely rid of the drug. Even so, most people will start to experience symptoms within a week, gradually worsening over time.

Side Effects of Stopping Antithyroid Medication

If you have Graves' disease, toxic nodules, thyroiditis, or another cause of hyperthyroidism, you may need to take PTU or Tapazole for 12 to 18 months to temper the overproduction of T3 and T4.

If you skip or stop your medicine entirely, you can experience a number of short- and long-term side effects, including:

  • Extreme weight loss
  • Abnormal hunger and thirst
  • Nervousness and anxiety
  • Heat intolerance with profuse sweating
  • Fatigue
  • Muscle weakness
  • Diarrhea
  • Nausea and vomiting
  • Irregular periods
  • Goiter (enlarged thyroid)
  • Bulging eyes (proptosis)
  • Insomnia
  • Rapid pulse
  • Heart palpitations
  • High blood pressure
  • Itching
  • Tremors
  • Hair loss

Untreated hyperthyroidism can increase your risk of stroke or heart attack. It can also increase the risk of a potentially life-threatening condition called a thyroid storm in which your heart rate, blood pressure, and body temperature can soar to dangerously high levels.

What Do I Do if I Miss a Dose?

If you miss a dose of any thyroid drug, take it as soon as you remember. However, if it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. Do not double up doses to catch up.

Why People Stop Treatment

People stop thyroid medications for many reasons, often placing their good health at risk. There are several tips and solutions that can help if you're not taking your thyroid drugs for any of the following reasons:

You're Not Feeling Better

Thyroid medications usually do not work right away. It can take a few days to a few weeks for you to start noticing a difference in how you feel.

If you don't feel better after taking your medication for several months, you may need a dose adjustment or a different medication. Speak with your healthcare provider.

You Have New or Worsening Symptoms

If you have lived with untreated thyroid disease for years, you may have gotten used to the symptoms. So you may understandably be dismayed when you start treatment and find yourself gaining weight, losing hair, having leg cramps, or experiencing changes in your menstrual cycle.

Talk to your healthcare provider, as these may be short-term effects of your thyroid drugs. Or, you may be over-treated and require a dose adjustment or a different medication entirely.

The risk of serious side effects due to thyroid medication is extremely small. Side effects are also most likely to occur within the first three months of treatment.

You Can't Afford Treatment

Paying for medications can be stressful. If you have private health insurance, Medicare, or Medicaid, most plans will cover thyroid medications fully or partially.

Switching from a brand-name drug like Synthroid to a generic formulation can also save money. If paying out of pocket, drug discount coupons can be found through programs like GoodRx, sometimes reducing costs by as much as 80%.

You Forget to Take Your Medicines

There are a number of strategies you can use to remember to take your drugs. Your phone, computer, or smartwatch can be programmed to give you a daily reminder. Keep your medications in an obvious place, like your bedroom or kitchen, and use a daily pill organizer to help you keep on track for the entire week.

You Prefer Natural Remedies

Armour Thyroid (desiccated thyroid) is an alternative to levothyroxine made from the dried thyroid gland of pigs. It has been used for over 100 years and appears effective in many users who swear by it. Even so, desiccated thyroid is not approved for the treatment of hypothyroidism by the U.S. Food and Drug Administration (FDA).

There are no natural substitutes for antithyroid medications.

You Like How Hyperthyroidism Makes You Feel

Hyperthyroidism can cause unwanted symptoms like anxiety and excessive sweating. But it can also cause weight loss and a reduced need for sleep, which some people welcome.

While you may consider some of the symptoms of hyperthyroidism beneficial, it is important to remember that the disease places extreme stress on your heart and bones, and places your overall health at risk.

When It's OK to Stop

People with mild hypothyroidism who have no notable symptoms (known as subclinical hypothyroidism) may not require treatment if levels of a hormone called thyroid stimulating hormone (TSH) are normalized. In such cases, treatment may be stopped if TSH levels remain normal for three to four months.

People on antithyroid drugs are generally treated for 12 to 18 months. After that, the dose may be slowly decreased or stopped if symptoms go away and if TSH levels are normal.

Treatment should only stopped (or the dose decreased) under the direction of a healthcare provider.

When to Talk to a Healthcare Provider

You need to be involved in the decisions regarding your care, and how you feel about your medication and its effects on your body are of great importance.

With a thyroid condition, your symptoms can be a good reflection of how well the medication is working. However, new symptoms and side effects associated with thyroid disease medication can make it difficult to know whether you feel better overall with or without it.

If you are feeling unsure about your thyroid medication, discuss your thoughts and feelings with your healthcare provider. Furthermore, it is important you fully understand the consequences of untreated thyroid disease.

Summary

Not taking your hypothyroid or hyperthyroid medication can cause undesirable and even life-threatening symptoms, ranging from fatigue and hair loss to infertility and death.

If you are feeling conflicted about taking thyroid medications, discuss your concerns with your healthcare provider. You may need a different medication or a dose adjustment, but you should never quit without your provider's approval.

8 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.
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By Mary Shomon
Mary Shomon is a writer and hormonal health and thyroid advocate. She is the author of "The Thyroid Diet Revolution."