When it comes to treating hypothyroidism, patients are often faced with a choice between desiccated thyroid and levothyroxine. Both medications aim to normalize thyroid hormone levels, but they differ in their composition, dosage, and the way they interact with the body. Understanding the differences between these two treatments can help individuals make informed decisions about managing their thyroid health.
What is Hypothyroidism?
Hypothyroidism occurs when the thyroid gland doesn’t produce enough thyroid hormones, particularly thyroxine (T4) and triiodothyronine (T3). These hormones are critical for regulating metabolism, energy levels, and overall bodily functions. Common symptoms of hypothyroidism include fatigue, weight gain, depression, cold intolerance, and dry skin.
To manage hypothyroidism, thyroid hormone replacement therapy is necessary. The two most common options are desiccated thyroid and levothyroxine. Less frequently, liothyronine (T3) may be prescribed.
What is Desiccated Thyroid?
Desiccated thyroid, also known as natural thyroid or thyroid extract, is derived from the dried thyroid glands of pigs (porcine thyroid). It contains a combination of both T4 (thyroxine) and T3 (triiodothyronine), as well as other thyroid hormones and components. Common brands of desiccated thyroid include Armour Thyroid and NP Thyroid. Desiccated thyroid composition includes: T4 and T3 hormones in naturally occurring ratios, plus other components like T1, T2, and calcitonin, which are also produced by a human thyroid gland.
Advantages of Desiccated Thyroid:
- Combination of T4 and T3: May benefit patients who have trouble converting T4 into the active T3 hormone. Some individuals report improvements in energy, mood, and cognitive function when taking desiccated thyroid compared to T4-only medications.
- Natural Source: Some patients prefer desiccated thyroid because it is derived from animal sources, typically porcine (pig), and considered a more “natural” option.
Disadvantages of Desiccated Thyroid:
- Inconsistent Dosage: One of the main challenges with desiccated thyroid is the variability in hormone levels. The amount of T3 and T4 in each batch can vary slightly, making it difficult to achieve precise hormone regulation.
- Higher T3 Levels: Desiccated thyroid contains more T3 than the human thyroid typically produces. T3 is more potent and fast-acting than T4, and some patients may experience symptoms of hyperthyroidism, such as anxiety, palpitations, or difficulty sleeping, if T3 levels become too high (1).
- Availability and Insurance Coverage: Desiccated thyroid is not as widely prescribed as levothyroxine, and insurance coverage for natural thyroid medications can sometimes be limited.
What is Levothyroxine?
Levothyroxine is a synthetic form of the hormone T4. It is the most commonly prescribed medication for hypothyroidism and is available under brand names like Synthroid, Levoxyl, and Tirosint. The body naturally converts T4 into T3 as needed, providing a steady and consistent level of thyroid hormone. These medications contain synthetic thyroxine (T4).
Advantages of Levothyroxine:
- Consistent Dosage: Levothyroxine is a synthetic medication, which means it is produced with precise and consistent dosages. This helps ensure stable thyroid hormone levels when taken as prescribed (2).
- Widely Available and Affordable: Levothyroxine is widely available and typically covered by most insurance plans. Its long history of use and extensive research make it a trusted and reliable option for thyroid hormone replacement therapy.
- Well-Studied: Levothyroxine has been extensively studied in clinical trials, and its safety and efficacy are well-documented. It is the standard of care for most patients with hypothyroidism (3).
Disadvantages of Levothyroxine:
- T4-Only: Some patients have difficulty converting T4 into the active T3 hormone, and may not experience full symptom relief. These individuals may continue to feel fatigued, depressed, or mentally foggy, even with normalized T4 levels (4). Patients who are “poor converters” may benefit from medications that provide both T4 and T3 (5).
Comparing Desiccated Thyroid and Levothyroxine
| FEATURE | DESICCATED THYROID | LEVOTHYROXINE |
| Source | Natural (porcine thyroid) | Synthetic T4 |
| Hormones Included | T4, T3, T1, T2, Calcitonin | T4 |
| Dosage Consistency | May be variable | Highly consistent |
| T3 Content | Higher T3 Levels | None |
| Effectiveness | May benefit those needing T3 | Standard treatment for most |
| Side Effects | Potential hyperthyroidism from excess T3 | May not address low T3 Symptoms |
| Cost/Availability | May be more expensive and less available | Affordable and widely available |
Who Might Benefit from Desiccated Thyroid?
Patients who do not experience adequate symptom relief with levothyroxine may consider switching to desiccated thyroid. Some studies suggest that adding T3 to treatment can improve mood, energy, and overall quality of life in patients who continue to experience symptoms despite normal T4 levels (6).
However, it’s important to note that desiccated thyroid may not be suitable for everyone. Patients with heart conditions or those sensitive to T3 may experience side effects like palpitations or anxiety.
Who Might Benefit from Levothyroxine?
Levothyroxine remains the first-line treatment for hypothyroidism because of its reliability, affordability, and extensive research supporting its use. For most patients, levothyroxine effectively normalizes thyroid hormone levels and alleviates symptoms of hypothyroidism. It is especially recommended for those with cardiovascular issues, as the steady release of T4 minimizes the risk of hyperthyroid symptoms (6).
In Conclusion
If you are considering these choices please reach out, we LOVE discussing the individual benefits of these and other hypothyroid treatments. The choice between desiccated thyroid and levothyroxine depends on individual preferences, response to treatment, and medical history. Desiccated thyroid may be more appealing to patients seeking a natural source of thyroid hormone or those who need additional T3. On the other hand, levothyroxine’s consistent dosing, affordability, and well-established efficacy make it the preferred option for many patients. Ultimately, working with a licensed Naturopathic Doctor can be beneficial to find the best treatment plan for managing your hypothyroidism.
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References
1. Hoang, T. D., et al. (2013). “Desiccated thyroid extract compared with levothyroxine in the treatment of hypothyroidism: a randomized, double-blind, crossover study.” Journal of Clinical Endocrinology & Metabolism.
2. Wiersinga, W. M. (2014). “Paradigm shifts in thyroid hormone replacement therapies for hypothyroidism.” Nature Reviews Endocrinology.
3. Garber, J. R., et al. (2012). “Clinical practice guidelines for hypothyroidism in adults: co-sponsored by the American Association of Clinical Endocrinologists and the American Thyroid Association.” Endocrine Practice.
4. Wiersinga, W. M. (2001). “Thyroid hormone replacement therapy.” Hormone Research.
5. Boeving, A., et al. (2011). “Low-normal or high-normal thyrotropin target levels during treatment of hypothyroidism: a prospective, comparative study.” Thyroid.
6. Nygaard, B., et al. (2009). “Effect of combination therapy with thyroxine (T4) and 3,5,3′-triiodothyronine (T3) and thyroxine monotherapy in patients with hypothyroidism: a double-blind, randomized cross-over study.” Journal of Clinical Endocrinology & Metabolism.
