Lyophilized Bovine Thyroid Gland
Also known as: Desiccated thyroid extract (DTE), natural desiccated thyroid (NDT), bovine thyroid glandular, Lyophilized Bovine Thyroid Gland
Overview
Lyophilized bovine thyroid gland is a preparation derived from the thyroid gland of cows (Bos taurus), processed by freeze-drying to preserve its natural glandular tissue and hormone content. It contains both thyroxine (T4) and triiodothyronine (T3) hormones in proportions similar to those naturally produced by the human thyroid. Historically and currently, it is used as a source of thyroid hormones for the treatment of hypothyroidism, particularly in patients who do not achieve adequate symptom control or feel well on synthetic levothyroxine (T4) alone. While its use has a long history, recent research, including randomized controlled trials and systematic reviews, has re-evaluated its efficacy and safety. It is categorized as a glandular supplement and an alternative/complementary medicine for thyroid hormone replacement. The primary benefit often cited by users is an improvement in patient-reported quality of life and symptom scores, although objective measures of thyroid function may not always show significant differences compared to synthetic T4.
Benefits
Lyophilized bovine thyroid gland (DTE) offers several potential benefits, primarily for individuals with hypothyroidism. The most significant reported benefit is an improvement in patient-reported quality of life (QoL) and symptom scores, especially in those who remain symptomatic or dissatisfied with levothyroxine (synthetic T4) monotherapy. A 2013 randomized controlled trial (n=70) found that 49% of participants preferred DTE over levothyroxine, with some noting weight loss, despite no significant difference in psychometric testing. Systematic reviews, while acknowledging low to moderate quality evidence, also suggest QoL improvements. These benefits are particularly relevant for patients who do not convert T4 to T3 efficiently or who feel better with a combination of both hormones. While objective thyroid function tests may normalize with both DTE and levothyroxine, the subjective well-being and preference for DTE highlight its potential role in personalized hypothyroidism management. However, the evidence quality is mixed, with limitations such as small sample sizes and heterogeneity in outcome measures across studies.
How it works
Lyophilized bovine thyroid gland functions by directly supplying both thyroxine (T4) and triiodothyronine (T3) hormones to the body. These hormones are crucial regulators of metabolism, growth, and development. Once absorbed, T4 can be converted to the more active T3, while the directly supplied T3 acts immediately. Both T4 and T3 exert their effects by binding to specific nuclear thyroid hormone receptors (alpha and beta) located within target cells throughout the body. This interaction modulates gene expression, influencing basal metabolic rate, cardiovascular function, neurological processes, and overall energy balance. The presence of both T4 and T3 in DTE aims to mimic the natural physiological secretion of the human thyroid gland, potentially offering a more comprehensive hormonal replacement compared to T4 monotherapy.
Side effects
When dosed appropriately, lyophilized bovine thyroid gland is generally considered safe; however, there is a risk of iatrogenic thyrotoxicosis if overdosed. Common side effects, reported in over 5% of users, include palpitations, mild tachycardia (rapid heart rate), and itchiness. Less common side effects (1-5%) may involve allergic reactions or intolerance to the preparation. Rare but serious side effects (<1%) can include cardiac arrhythmias, particularly in susceptible individuals. Drug interactions are similar to those of levothyroxine; absorption can be significantly affected by concurrent intake of calcium, iron supplements, and certain foods, necessitating careful timing of administration. Contraindications for DTE use include untreated thyrotoxicosis, acute myocardial infarction, and adrenal insufficiency unless adequately managed with glucocorticoid coverage. Caution is advised for elderly patients or those with pre-existing cardiac disease due to an increased risk of palpitations and arrhythmias. Regular monitoring of thyroid function tests is crucial to prevent overtreatment and associated adverse effects.
Dosage
The optimal dosage of lyophilized bovine thyroid gland is highly variable and must be individualized based on the patient's specific thyroid hormone content requirements and clinical response. Due to potential variability in glandular preparations, standardized pharmaceutical products are preferred for consistency. Dosage typically begins low and is gradually titrated upwards to achieve normal thyroid-stimulating hormone (TSH) levels and effective symptom control. The maximum safe dose is defined by the point at which TSH levels are suppressed below the normal range, as this indicates overtreatment and increases the risk of thyrotoxicosis. DTE is usually taken once daily on an empty stomach to ensure consistent absorption. It is crucial to avoid concurrent intake with substances known to impair absorption, such as calcium and iron supplements, or certain foods. While no specific cofactors are required, regular monitoring of thyroid function tests (TSH, free T4, free T3) is essential to guide dosage adjustments and ensure safety and efficacy.
FAQs
Is lyophilized bovine thyroid gland safe?
Yes, when prescribed and monitored appropriately by a healthcare professional, it is generally safe. However, overdosing can lead to serious side effects like thyrotoxicosis.
Is it better than levothyroxine?
Some patients report better quality of life and symptom control with DTE, but objective measures often show no significant difference. Evidence is mixed, and it's not universally superior.
How long until effects are seen?
Improvements in symptoms and overall well-being can typically be observed within a few weeks to several months after starting or adjusting the dosage.
Can it cause heart problems?
Yes, especially if the dosage is too high or in individuals with pre-existing heart conditions. It can lead to palpitations, rapid heart rate, and in rare cases, arrhythmias.
Is it standardized?
Pharmaceutical-grade DTE products are standardized for hormone content. However, some over-the-counter supplements may vary in potency, making consistent dosing challenging.
Research Sources
- https://portal.findresearcher.sdu.dk/files/265931781/RiisManuscript_clean.pdf – This systematic review by Riis et al. (2024) analyzed multiple studies on hypothyroid patients, finding that Desiccated Thyroid Extract (DTE) improved quality of life (QoL) compared to levothyroxine (LT4) in some studies. It noted low heterogeneity among studies but highlighted adverse effects like palpitations. The overall quality of evidence was assessed as low to moderate due to limitations in the included studies.
- https://www.endocrine-abstracts.org/ea/0101/ea0101ps3-25-09 – Ryom et al. (2024) conducted a qualitative synthesis of two RCTs and nine non-randomized studies, concluding no significant QoL difference in RCTs between DTE and LT4, though non-randomized studies favored DTE. The review also noted increased heart rate and lower HDL with DTE, emphasizing overall low to moderate evidence quality and methodological concerns.
- https://www.thyroid.org/patient-thyroid-information/ct-for-patients/vol-6-issue-8/vol-6-issue-8-p-3/ – The Hoang et al. (2013) study, a double-blind crossover RCT involving 70 hypothyroid patients, found that 49% preferred DTE over levothyroxine. While there was no difference in psychometric tests, DTE was associated with weight loss, and both treatments normalized thyroid tests. This study, despite its small sample size and short duration, provides good RCT design evidence for patient preference.
- https://pmc.ncbi.nlm.nih.gov/articles/PMC10289114/ – McCullough (2023) provided a narrative review suggesting DTE is comparable to levothyroxine, with a subgroup of patients symptomatic on LT4 preferring DTE or combination therapy. The review emphasizes the need for cautious dosing. As a narrative review, it synthesizes existing evidence but lacks the systematic rigor of a meta-analysis.