8 Hypothyroidism Medication Mistakes to Avoid

1. Taking Your Thyroid Medication With Meals and Snacks

The synthetic thyroid hormone won’t be absorbed properly unless you take it on an empty stomach and wait 45 to 60 minutes afterward before eating, Bianco says.

The simplest way to accomplish this is to take your thyroid medication first thing in the morning — but note that your morning coffee can also impair thyroid hormone absorption, so it’s best to wait 45 minutes before drinking coffee. Bianco says he has patients who set an alarm for 5 a.m., take the medication, and go back to sleep to ensure they’re taking it on an empty stomach. If you choose to take your thyroid medication at night, it’s important that you don’t eat for four hours before taking it.

2. Combining Your Synthetic Thyroid Hormone With Other Medication

Just as there shouldn’t be food in your stomach when you take your hypothyroidism medication, it’s also important to avoid taking certain other medications at the same time.

Specifically, antacids, calcium, cholesterol-lowering drugs, iron supplements, and some multivitamins (including most prenatal vitamins) can interfere with the way the thyroid hormone is absorbed. So you should take these particular medications and supplements four hours before or after taking your thyroid medication, according to MedlinePlus. Most other medications can typically be taken 45 minutes to an hour after your hypothyroidism treatment, Bianco says.

RELATED: How Is Hypothyroidism Treated? Medications and Supplements to Consider and Avoid

3. Starting or Stopping Other Medication Without Talking to Your Doctor

Some medications will affect the way your thyroid hormone works in the body, including birth control pills, estrogen, testosterone, seizure drugs, and some antidepressant medications, according to the American Thyroid Association (ATA). That doesn’t mean you can’t take these other drugs — but if you do, make sure your doctor is aware. It will likely just take some trial and error to find the effective dose of thyroid hormone you’ll need as a result, Bianco says. Likewise, any time you stop taking these drugs or make any changes, your thyroid hormone dose may need to be adjusted, and you should see your healthcare provider then, too.

4. Assuming a Change in Medication Brand Isn’t a Big Deal

Per the ATA, every brand and generic thyroid medication contains the same amount of thyroid replacement hormone. However, many endocrinologists believe that there is a variation in hormone content among the various brands, and there are additional factors that can interfere with how the hormone is absorbed with each one, notes the ATA. Therefore, when getting a prescription filled at the pharmacy, you should not change from one brand to another, from a brand name to a generic, or from one generic to another without first checking with your doctor. To help ensure this, check that your tablets are always the same shape when you get a refill from the pharmacy.

RELATED: 6 Healthy Food Swaps for Hypothyroidism

5. Taking Too Much Thyroid Hormone and Thinking It’s Harmless

The synthetic thyroid hormone T4 is relatively safe, and you shouldn’t worry if you accidentally take an extra dose, Bianco says. But taking an excessive amount could have side effects — it can make you feel tired, affect your sleep and concentration, lead to bone loss, or cause an irregular heartbeat, according to the Cleveland Clinic. If you take combination therapy, which contains both T4 and T3, the medication needs to be taken precisely as prescribed, as taking too much can be dangerous. The ATA notes that potential side effects of taking too much combination therapy include a racing pulse, anxiety, trouble sleeping, and problems with your heart and bones. Contact your healthcare provider immediately if you accidentally take more than prescribed.

6. Inconsistently Taking Your Prescribed Thyroid Medication

For your thyroid medication to work properly, you need to take it regularly and consistently. Skipping doses, taking your medication in the morning one day and in the evening the next, or taking it with food some days and on an empty stomach other days can affect how the medication is absorbed. You should take the correct dose of thyroid medication at the same time, and in the same way, every day, according to the ATA. Use a pillbox or set an alarm on your phone if you need help remembering to take your pill. If you do miss a dose of your thyroid medication, take the missed dose as soon as you remember, advises the ATA. But if it’s almost time for your next dose, double up the next day because the life of the medication is long in the body, notes the ATA.

RELATED: 6 Ways to Stay On Top of Your Hypothyroid Medication

7. Overindulging on Certain Foods, Which Can Also Affect How Your Thyroid Meds Work

For the most part, you shouldn’t have problems with most foods if you wait at least 45 minutes after taking your thyroid medication before you eat. But if you don’t wait long enough, certain foods may impair absorption of the hypothyroid medication more than others, says Deena Adimoolam, MD, a specialist in endocrinology, diabetes, and metabolism with Summit Health in Clifton, New Jersey. That includes foods that are high in calcium, such as milk, cheese, yogurt, kale, and spinach.

Eating a lot of soy has also been thought to impair the absorption of thyroid hormone, but a review of studies noted that it’s not necessary for most people with thyroid disease to avoid soy foods because medication dosage can be adjusted accordingly, if necessary. If you eat about the same amount of soy every day, your healthcare provider has probably found the proper dose of thyroid hormone to counteract soy’s effects. So just be sure to stay consistent with your soy intake.

RELATED: How Diet and Lifestyle Choices Can Help You Manage Hypothyroidism

8. Not Talking to Your Doctor Before Taking Supplements

Your healthcare provider should know about any supplements you take because they may affect your hypothyroidism treatment — particularly iodine. While iodine is essential for your body to produce thyroid hormone, the vast majority of people in the United States get enough iodine from food and water alone, Dr. Adimoolam says. Because taking too much iodine can cause thyroid hormone levels to go too high or too low, it’s best to avoid this supplement.

RELATED: Iodine Defined: Why You Need the Nutrient

Additional reporting by Deb Shapiro.