Medically reviewed by
Dr. Minako Abe, M.D., Board-certified emergency medicine physician researching the relationship between lifestyle and disease onset in relation to the immune system and cancer, Japan
Desiccated thyroid extracts, often referred to as desiccated thyroid or thyroid extract, are medications derived from the thyroid glands of animals, usually pigs. The thyroid is a small, butterfly-shaped gland located in the neck that plays a crucial role in regulating the body’s metabolism by producing thyroid hormones. These extracts have been used for over a century to treat thyroid disorders, especially hypothyroidism.
In this article, we will explore what desiccated thyroid extracts are, how they work, and their advantages and disadvantages compared to synthetic alternatives.
What are desiccated thyroid extracts?
As mentioned earlier, desiccated thyroid extracts are medications that are usually prepared from porcine thyroid tissue (thyroid glands of pigs). Other animal sources include cows and sheep. The thyroid glands are dried, powdered, and processed to remove impurities and excess hormones, resulting in a concentrated source of thyroxine (T4) and triiodothyronine (T3). These hormones are essential for regulating metabolism, energy production, temperature control, and maintaining healthy skin, hair, and nails.
The thyroid gland is a small, butterfly-shaped organ located in the neck that plays a crucial role in regulating the body’s metabolism by producing thyroid hormones, primarily thyroxine and triiodothyronine. These hormones are essential for various bodily functions, including energy production, temperature regulation, and maintaining healthy skin, hair, and nails.
How do desiccated thyroid extracts work?
Desiccated thyroid extracts contain both T4 and T3 hormones, mimicking normal thyroid function. When ingested, these extracts release T4 and T3 into the bloodstream. T4 is an inactive form of thyroid hormone, which the body converts into the active T3 as needed. This dual hormone approach can address thyroid hormone deficiencies more comprehensively than synthetic alternatives like levothyroxine, which often only contain T4.
Synthetic vs. Natural Thyroid Hormone Medications
Synthetic thyroid medications, such as levothyroxine and liothyronine, have become the standard treatment for hypothyroidism due to their consistent dosing and well-documented safety profiles. However, before the advent of these medications, desiccated thyroid extracts were the primary treatment for hypothyroidism. Today, desiccated thyroid extracts are used much less frequently than they used to be many years ago. It is worth mentioning that these extracts remain an option for patients seeking a more natural thyroid hormone replacement or those who do not respond well to synthetic medications.
In the next section, we will look at some of the arguments for and against the use of natural thyroid hormone medications.
What are the Pros and Cons of Desiccated Thyroid Extracts?
Pros
1. Comprehensive Hormone Replacement
Desiccated thyroid extracts provide both T4 and T3, which can benefit patients who have difficulty converting T4 to T3.
2. Symptom Improvement
Even though many endocrinologists do not recommend the use of thyroid extracts, some patients report better symptom management with desiccated thyroid extracts compared to synthetic thyroxine (levothyroxine). A study in the Journal of Clinical Endocrinology and Metabolism, published in 2013, found that almost half of the participants preferred desiccated thyroid extracts to levothyroxine.
Cons
1. Variability
The hormone content in desiccated thyroid extracts can vary between batches and brands, making consistent dosing making it challenging to maintain consistent dosing. This can also result in varying therapeutic effects. (The use of these extracts therefore need to be rigorously regulated and their production standardized to the same degree as synthetic thyroid medication).
2. Allergic Reactions
Rarely, individuals may experience allergic reactions to animal-derived thyroid extracts, presenting as swelling, rashes, itching, or blistered skin.
3. Potential Overdose
As these extracts contain both T4 and T3, there is a risk of overdose, which can cause thyrotoxicosis and result in symptoms of hyperthyroidism, including palpitations, anxiety, and weight loss. Also, for healthy euthyroid individuals who use desiccated thyroid extracts solely for the purpose of weight loss, this can be fatal.
Key Considerations
Desiccated thyroid extracts are a potential option for patients who do not respond well to synthetic thyroid medications and who prefer a more “natural” approach. However, it is important to also note that their use is somewhat controversial, and not all healthcare professionals endorse them. If you are considering desiccated thyroid extracts, consult with your healthcare provider who is qualified to help determine if they are the right choice for you. Currently, desiccated thyroid extracts are available under various brand names such as Armour Thyroid and Nature-Thyroid.
Key Takeaways
Desiccated thyroid extracts supplement the body’s thyroid hormone levels with both T4 and T3.
They offer an alternative treatment for hypothyroidism, especially for those who do not respond well to synthetic T4-only medications.
These extracts provide a natural hormone balance but come with potential side effects and require careful monitoring.
While they may benefit some patients, their use is controversial and not universally endorsed by healthcare professionals.
Drawbacks include variability in hormone content, risk of overdose, and potential allergic reactions.
Not all individuals with thyroid disorders are suitable candidates for desiccated thyroid extracts; treatment should be personalized.
Synthetic thyroid medications are more commonly prescribed due to their reliability and precise dosing.
