What Happens When You Don't Take Your Thyroid Medication?

Consider this interesting situation. A 20-something woman, diagnosed with autoimmune Hashimoto's thyroiditis and hypothyroidism, decided not to take the thyroid medication her doctor had prescribed. The woman said that since starting her treatment, her irregular, scanty periods had actually become regular. The young woman preferred having fewer menstrual periods, and so she decided to stop taking her thyroid hormone replacement medication.

She felt that the benefits she'd noticed since starting treatment—losing weight, less hair loss, and more energy—were simply not worth the tradeoff of more regular and frequent menstrual periods.

She's not alone in refusing to take her prescribed medications. We've heard from other patients who don't take their thyroid medications. There are some common reasons that you may decide you don't want to take your any thyroid medication—whether your thyroid hormone replacement pills, or antithyroid drugs. For example, you may find yourself offering one of the following excuses: 

• "I don't feel any different/better, so why keep taking it?"
• "I didn't start having symptoms until I started taking the medication."
• "I don't like taking any prescription medications."
• "I can't afford it."
• "I have side effects I don't like when I take the medication."
• "I can't remember to take it every day."
• "I'd rather just take natural remedies, like herbs or vitamins."

If you're hyperthyroid, you may have the following additional reasons why you don't want to take your prescribed antithyroid drugs:

• "I'm worried about the side effects." (Antithyroid drugs do have a very small risk of serious side effects.)
• "I actually like how I feel when I'm hyperthyroid much more than when I'm hypothyroid."

If you don't take your prescribed medication, what can happen? Let's take a look.

Hypothyroid? The Risks of Not Taking Your Thyroid Hormone Replacement Medication

If you are hypothyroid—whether due to Hashimoto's, Graves' disease treatment, thyroid surgery, or congenital hypothyroidism—failing to take your thyroid hormone replacement medication (i.e., levothyroxine, or natural desiccated thyroid) can pose many risks to your health. These risks include the following:

• Blood pressure irregularities, elevated cholesterol (including treatment-resistant high cholesterol), and increased risk of heart disease
• Low body temperature; feeling perpetually cold
• Fatigue, muscle weakness, or joint pain
• Depression
• Memory problems
• Weight gain; inability to lose weight despite diet and exercise
• Infertility, miscarriage, stillbirth, or premature labor
• Menstrual irregularities
• Loss or reduction of sex drive
• Constipation
• Hair loss
• Swollen hands, feet, and face
• Growth of thyroid nodules, increasing goiter size
• Increased risk of infection

Ultimately, if deprived of thyroid hormone for a long period, and if your thyroid has been surgically removed or is not producing thyroid hormone for other reasons, you face a very dangerous condition—myxedema coma—which can ultimately be fatal.

Of particular importance, thyroid cancer patients who fail to take their thyroid hormone replacement medication at the prescribed dosage actually increase their risk of thyroid cancer recurrence.

Hyperthyroid? The Risks of Not Taking Your Antithyroid Medication

If you are hyperthyroid—whether due to Graves' disease or toxic nodules, among other reasons—failing to take your antithyroid medication—for example, methimazole or propylthiouracil/PTU—can pose a number of risks to your health, including:

• Debilitating weight loss or weight gain
• Dramatically increased appetite and thirst
• Nervousness, anxiety, panic attacks

• Heat intolerance, sweating
• Fatigue or muscle weakness
• Diarrhea, nausea, and vomiting
• Menstrual irregularities
• Goiter/enlarged thyroid
• Muscle weakness
• Insomnia
• Rapid pulse, heart palpitations, or high blood pressure
• Itching
• Tremors
• Hair loss
• Protruding eyes

Failing to treat hyperthyroidism can increase your risk of stroke or heart attack. A subset of untreated people with hyperthyroidism also develop a very dangerous condition known as thyroid storm, which has a high fatality rate.

Rethinking Your Excuses for Not Taking Medication

Clearly, there are sensible health reasons to take your prescribed thyroid medication. But if you are not taking medications, here are some thoughts on the reasons you might be using to justify that decision:

It isn't making you feel better: Don't expect thyroid medications to work like an aspirin for a headache. If you have just started taking thyroid hormone replacement medication or antithyroid drugs, it can take a few days to a few weeks to even start noticing a difference in how you feel. If you have been taking your medication for a number of months, and you still don't feel well, you may need a dosage adjustment or a change in medication—not a complete stop in your medication regimen.

You experience new or worsening symptoms after starting the medication: Integrative physicians note that some hypothyroid patients have adrenal fatigue, and when they begin thyroid hormone replacement medication, symptoms may actually worsen because the underlying adrenal problem has not been addressed. 

Your hair is falling out: If the primary new symptom you're experiencing is hair loss, note that levothyroxine can cause hair loss in some patients. To avoid hair loss, you may need a different thyroid hormone replacement medication.

You'd rather use natural remedies instead of prescription medications: Unfortunately, there isn't a natural or herbal replacement for thyroid hormone. Just like a type 1 diabetic needs insulin—a crucial hormone for survival—you need thyroid hormone for survival. And there are no natural substitutes for antithyroid drugs.

You can't afford the medication: Thyroid medication is not particularly expensive. Even if you pay out of pocket, the most costly thyroid medications shouldn't run more than around $30-$40 a month, and can be as low as $4 a month for generics. You may even be eligible for brand name prescription drugs through various low-cost programs.

You don't like how your medication makes you feel: If you are experiencing unwanted side effects, your first stop is your doctor. You may need a dosage change, or even a different medication, to avoid certain side effects.

It's difficult to remember to take it every day: If you can remember to brush your teeth every day, you can remember to take your thyroid medication. If the main reason you're not taking your medication is that you just can't remember your pill every day, it's time to figure out a way to ensure you take your medication. So many people also have smartphones these days, and your phone can be programmed to give us a daily reminder call or alarm. This may be just what you need to remember to take your medication.

You're worried about the side effects of antithyroid drugs: Certainly, keep in mind that the risk of serious side effects is extremely small, and far less than the risks of remaining hyperthyroid. They are also most likely to occur within the first three months of treatment, so that is the time to be most vigilant. If you develop a sore throat or fever, or other signs or symptoms of infection in those first few months, contact your doctor right away. If you are on long-term antithyroid drug therapy, you may wish to ask your doctor to regularly schedule blood work to evaluate your white blood cell count as well.

You like how you feel when you're hyperthyroid: You may like the feeling of being hyperthyroid, but unfortunately, you may not realize the strain this condition is putting on your heart, bones, and overall health. Liking the feeling of hyperthyroidism is similar to being addicted to a stimulant such as nicotine or caffeine. Untreated hyperthyroidism can have serious consequences to your health. Integrative physicians believe that some patients who like this feeling of being hyperstimulated may have underlying adrenal fatigue or exhaustion that should be addressed.

A Word From Verywell

Ultimately, if you aren't comfortable taking your thyroid medication, the solution may be to get a new thyroid doctor. Having a practitioner you can trust may help you get on track with the right treatment that will work for you.