Armour Thyroid: What It Does and Who Shouldn't Take It

Table of Contents
View All
Table of Contents

Armour Thyroid is a type of desiccated thyroid (DTE) medication used to treat hypothyroidism by replacing missing thyroid hormones, specifically T4 and T3. Some people prefer it because it provides both hormones directly, while synthetic medications like levothyroxine only provide T4.

Healthcare providers may hesitate to prescribe Armour Thyroid due to potential inconsistencies in its potency. It’s not suitable for everyone, especially those who are pregnant, taking weight loss medications, or allergic to pork. Using Armour Thyroid improperly can lead to serious, life-threatening complications, so it’s essential to take it exactly as prescribed.

While pill
Apisit Sorin/EyeEm/Getty Images

What Does Armour Thyroid Do?

Armour Thyroid is a brand of natural desiccated thyroid (DTE) medication used to treat hypothyroidism. It is made from the dried and powdered thyroid glands of pigs and contains a mix of thyroid hormones, including thyroxine (T4) and triiodothyronine (T3).

The hormones in Armour Thyroid help regulate metabolism, energy levels, and overall thyroid function by balancing thyroid hormone levels. Some people feel better on Armour Thyroid because it contains both T3 and T4, while synthetic levothyroxine only has T4, which the body must covert into T3 for energy and metabolism.

If somebody's body doesn't convert T4 to T3 well, they may feel tired and unwell on levothyroxine. For these individuals, Armour Thyroid may be more helpful because it provides both hormones directly, which can more effectively relieve symptoms.

Is Armour Thyroid FDA-Approved?

DTE was created before the U.S. Food and Drug Administration (FDA) was established, so it was allowed to stay as a prescription medicine. Although the FDA regulates it now, DTE never went through the approval process that new drugs must follow. This means it is not officially FDA-approved.

Why Providers Might Not Prescribe It

Some healthcare providers hesitate to prescribe Armour Thyroid because of its history of inconsistent potency, which gave it a lasting reputation as unreliable.

Although its stability has improved, levothyroxine became the preferred treatment in the 1970s after researchers confirmed that the body can convert T4 into T3, and physicians developed better tests to monitor thyroid levels.

Since levothyroxine is standardized, predictable, and widely recommended in medical guidelines, many providers see it as the safest and most reliable option.

However, some people who don’t feel well on levothyroxine look for alternatives like Armour Thyroid, keeping the debate over treatment options ongoing.

Thyroid Disease Doctor Discussion Guide

Get our printable guide for your next doctor's appointment to help you ask the right questions.

Doctor Discussion Guide Woman

Benefits

A 2018 survey of over 12,000 people with hypothyroidism found that those taking DTE were more satisfied with their treatment and healthcare providers than those on levothyroxine or levothyroxine with T3. They also reported fewer issues with memory, weight, fatigue, and energy levels.

Some people report better mood, memory, concentration, sleep, and energy on DTE. However, research has not found significant overall differences in general health, pain levels, depression, anxiety, or quality of life when comparing DTE to T4-only treatment.

The choice between Armour Thyroid and other thyroid medications is highly individual—what works well for one person may not be the best option for another.

Possible Side Effects

Side effects can occur when taking DTE, including:

Side effects from Armour Thyroid are uncommon and typically occur when the body is adjusting to the medication. These effects are usually temporary and resolve as your body adapts. If side effects persist or become bothersome, consult your healthcare provider. 

Other Risks

Taking too much or too little Armour Thyroid can cause serious health issues. DTE must always be taken exactly as prescribed. Using it improperly can lead to:

  • Problems with growth and development
  • Heart problems, such as irregular heart beat and fast heart rate
  • Bone density loss and fractures
  • Reproductive problems, including fertility issues and irregular periods
  • Mood swings, anxiety, or depression
  • Gastrointestinal issues, such as constipation or diarrhea
  • Poor blood sugar control, increasing the risk of diabetes

Other risks associated with DTE that could affect your treatment include:

  • Availability issues: Shortages can occur, potentially requiring a switch to other brands or sourcing from countries like Canada.
  • Dosage variability: As a natural product, the amounts of thyroid hormones (T4 and T3) in each dose can vary, making it harder to get the exact right dose compared to synthetic thyroid medicine, which is made to be consistent.
  • Different T4 to T3 ratio: Pig thyroid has a different balance of T4 to T3 than humans. DTE contains more T3 than your body naturally produces, which could lead to higher levels of T3.
  • Risk of thyrotoxicosis: T3 is much stronger than T4, so DTE can cause temporary spikes in thyroid hormone levels, potentially leading to symptoms of thyrotoxicosis (too much thyroid hormone). Regular testing of free T4 and free T3 levels is necessary to keep them within a safe range.

If you're considering starting treatment with Armour Thyroid, speak with your healthcare provider about any concerns you have.

Over-the-counter thyroid supplements are not the same as prescription DTE and may pose health risks. Purchasing DTE from other countries without a prescription and your healthcare provider's approval can be dangerous. If a shortage occurs, consult your provider before changing your medication.

Who Should Not Take It

You shouldn't use DTE if you're allergic to any of the ingredients it contains, such as pork, or if you have an overactive thyroid or untreated adrenal issues.

Armour Thyroid is not right for everyone. This medication is contraindicated in people with:

  • Allergies to any of its ingredients, such as pork
  • People with overactive thyroid (hyperthyroidism)
  • Untreated adrenal issues or issues with the pituitary gland
  • Serious health conditions like diabetes and heart disease
  • People who can become pregnant
  • People taking weight loss medications

During pregnancy, the developing baby depends on the mother's thyroid hormone, T4, for brain development. Armour Thyroid has a different balance of thyroid hormones than humans. This difference can lead to higher T3 levels, which may affect the baby's brain development.

Using Armour Thyroid alongside other weight loss medications can lead to serious health problems, including heart issues and dangerously high thyroid hormone levels. Combining these treatments without medical approval is not safe and can be life-threatening.

Be sure to tell your healthcare provider about all prescription or over-the-counter medications, vitamins, supplements, and herbal products you're taking, as DTE can interact with many of these.

How It's Taken

Armour Thyroid is an oral tablet. It should be taken on an empty stomach, and you should wait one hour after taking it to drink or eat anything other than water.

Armour Thyroid comes in these strengths:

  • 15 milligrams (mg)
  • 30 mg
  • 60 mg
  • 90 mg
  • 120 mg
  • 180 mg
  • 240 mg
  • 300 mg

For most people with hypothyroidism, the typical starting dose is 30 mg taken once per day. Your healthcare provider will likely start you on a low dosage then gradually increase it. For example, they may increase your dosage by 15 mg every two to three weeks.

For children with hypothyroidism, dosage is based on the child's weight and age:

Age Dosage by Weight Average Daily Dose
Younger than 6 months 4.8 to 6 mg/kg once daily 15 to 30 mg once daily
6 months to less than 1 year 3.6 to 4.8 mg/kg once daily 30 to 45 mg once daily
1 to 5 years 3 to 3.6 mg/kg once daily 45 to 60 mg once daily
6 to 12 years 2.4 to 3 mg/kg once daily 60 to 90 mg once daily
Older than 12 years 1.2 to 1.8 mg/kg once daily More than 90 mg once daily

Like other thyroid medications, once you start Armour Thyroid, you should expect to take it for life. If you need to switch doses or change to a different thyroid medication, you will need to work with your healthcare provider to ensure a safe transition.

A thyroid medicine made from cow thyroid (bovine thyroid) is available for people who don't eat pork for religious or cultural reasons. Let your healthcare provider know if you prefer this option.

Summary

Armour Thyroid is a medication derived from pig thyroid glands, used to treat hypothyroidism by providing both T4 and T3 hormones. This combination can help regulate metabolism and energy levels, potentially improving symptoms for some individuals.

However, Armour Thyroid may cause side effects such as weight loss, fatigue, heart palpitations, and sleep disturbances. Additionally, its potency can vary, and it may not be suitable for everyone, especially those with certain health conditions or during pregnancy.

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.
  1. Armour Thyroid. Armour Thyroid is a dessicated thyroid extract (DTE) containing T3 and T4 thyroid hormones and is used to treat hypothyroidism.

  2. Riis K, Larsen CB, Bonnema SJ. Potential risks and benefits of desiccated thyroid extract for the treatment of hypothyroidism: a systematic review. Thyroid. 2024 Jun;34(6):687-701. doi:10.1089/thy.2023.0649

  3. Heald AH, Taylor P, Premawardhana L, Stedman M, Dayan C. Natural desiccated thyroid for the treatment of hypothyroidism?. Front Endocrinol. 2024;14(1):1309159. doi:10.3389/fendo.2023.1309159

  4. Shah M, Proumen R, Sunkara A, Acharya R, Patel A. A tale of two therapies: A comparison of Armour Thyroid and levothyroxine. J Endocr Soc. 2021;5(1):823–824. doi:10.1210/jendso/bvab048.1678

  5. Peterson SJ, Cappola AR, Castro MR, et al. An Online Survey of Hypothyroid Patients Demonstrates Prominent Dissatisfaction. Thyroid. 2018;28(6):707-721. doi:10.1089/thy.2017.0681

  6. Toloza FJK, Espinoza Suarez NR, El Kawkgi O, et al. Patient experiences and perceptions associated with the use of desiccated thyroid extract. Medicina (Kaunas). 2020;56(4):161. doi:10.3390/medicina56040161

  7. Armour Thyroid. About Armour Thyroid.

  8. National Institues of Health. Armour Thyroid.

Mary Shomon

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