Levothyroxine
Synthetic thyroid hormone for hypothyroidism and thyroid disorders
Levothyroxine is a synthetic thyroid hormone used to treat hypothyroidism (underactive thyroid gland). It is the most commonly prescribed thyroid medication worldwide, with over 100 million prescriptions annually. Levothyroxine is identical in structure and function to the naturally occurring thyroid hormone thyroxine (T4) and is considered safe and effective for long-term use when dosed correctly and monitored regularly.
Quick Facts
Key Takeaways
- Levothyroxine is the standard treatment for hypothyroidism and is typically taken as a lifelong daily medication
- Take on an empty stomach in the morning, at least 30 minutes before eating, for optimal absorption
- Dose is highly individualized and requires regular blood tests (TSH levels) to optimize
- Many common medications and supplements (calcium, iron, antacids) can interfere with absorption — separate by at least 2–4 hours
- Safe during pregnancy and breastfeeding, but dose adjustments are often needed during pregnancy
What Is Levothyroxine and What Is It Used For?
Quick Answer: Levothyroxine is a synthetic version of the thyroid hormone thyroxine (T4). It is used to replace or supplement the body's natural thyroid hormone when the thyroid gland cannot produce enough on its own, most commonly in hypothyroidism.
The thyroid gland, located at the front of the neck, produces hormones that are essential for regulating metabolism, energy production, body temperature, heart rate, and growth. When the thyroid fails to produce adequate amounts of these hormones — a condition known as hypothyroidism — levothyroxine provides the replacement hormone the body needs to function normally.
Levothyroxine sodium is structurally identical to endogenous thyroxine (T4). After absorption from the gastrointestinal tract, it is converted to the biologically active form, triiodothyronine (T3), in peripheral tissues including the liver, kidneys, and brain. T3 then binds to nuclear thyroid receptors, regulating gene expression that controls metabolic rate, protein synthesis, and cellular development.
Levothyroxine has a long half-life of approximately 6–7 days, which means that once-daily dosing provides stable and consistent blood levels. This pharmacokinetic profile makes it well-suited for chronic replacement therapy, and it is the most widely prescribed medication for thyroid disorders globally. The American Thyroid Association (ATA), European Thyroid Association (ETA), and World Health Organization (WHO) all recommend levothyroxine as the first-line treatment for hypothyroidism.
Approved Uses
Levothyroxine is approved and used for the following conditions:
- Hypothyroidism: Replacement of thyroid hormones when the thyroid gland does not produce enough, whether due to Hashimoto's thyroiditis, thyroid surgery, radioactive iodine treatment, or congenital hypothyroidism
- Goiter prevention: To prevent recurrence of goiter (enlarged thyroid) after thyroid surgery in patients with normal thyroid function
- Benign goiter treatment: To reduce the size of non-toxic goiter in patients with normal thyroid function
- Thyroid cancer suppression: To suppress TSH (thyroid-stimulating hormone) after thyroidectomy for malignant thyroid disease, thereby reducing the risk of tumor recurrence
- Adjunct therapy in hyperthyroidism: Used alongside antithyroid medications in certain treatment protocols
- Diagnostic use: In thyroid suppression testing to evaluate thyroid function
Levothyroxine is one of the most prescribed medications in the world. In the United States alone, it is consistently among the top 3 most prescribed drugs, with over 100 million prescriptions filled annually. Hypothyroidism affects approximately 4–5% of the adult population, making thyroid hormone replacement one of the most common chronic therapies.
What Should You Know Before Taking Levothyroxine?
Quick Answer: Before starting levothyroxine, your doctor should evaluate your heart health, adrenal function, and current medications. Certain conditions and drug interactions require careful dose adjustment and monitoring.
Levothyroxine is generally a well-tolerated medication when used at the correct dose. However, there are important medical conditions, precautions, and contraindications that both patients and healthcare providers must be aware of before starting treatment. A thorough medical evaluation, including blood tests and assessment of cardiac status, should precede the initiation of levothyroxine therapy.
Contraindications
Do not take levothyroxine if you have any of the following conditions:
- Allergy to levothyroxine sodium or any excipient in the formulation
- Acute myocardial infarction (recent heart attack), acute myocarditis (inflammation of the heart muscle), or acute pancarditis
- Untreated adrenal insufficiency (Addison's disease) — adrenal function must be corrected before starting thyroid hormone replacement, as levothyroxine can precipitate an adrenal crisis
- Untreated thyrotoxicosis (overactive thyroid) — unless used as part of combination therapy with antithyroid drugs
- Pregnancy combined with antithyroid drugs — levothyroxine must not be used simultaneously with thyrostatic medications during pregnancy
Warnings and Precautions
Special caution and careful dose titration are required in the following situations:
Levothyroxine should never be used for weight loss purposes. In patients with normal thyroid function, taking additional thyroid hormones will not cause weight loss and can lead to serious or life-threatening adverse effects, particularly when combined with weight-loss products. These effects include cardiac arrhythmias, angina pectoris, and thyrotoxicosis.
Cardiovascular disease: Patients with hypertension, arrhythmias, atherosclerosis, angina pectoris, or coronary artery disease require a very low starting dose (typically 12.5–25 mcg daily) with slow, gradual increases. Thyroid hormones increase cardiac workload and oxygen demand, which can worsen existing heart conditions. Frequent monitoring of thyroid function and cardiac status is essential throughout treatment.
Elderly patients: Older adults are more sensitive to the cardiac effects of thyroid hormones and require cautious dosing. Starting doses should be lower, typically 25 mcg daily, with incremental increases at 4–6 week intervals under close medical supervision.
Diabetes mellitus: Levothyroxine may decrease the effectiveness of antidiabetic medications (insulin and oral hypoglycemic agents). Blood glucose levels should be monitored more frequently when initiating or adjusting levothyroxine therapy, as dose adjustments of diabetes medications may be necessary.
Anticoagulant therapy: Levothyroxine can enhance the effect of coumarin anticoagulants (e.g., warfarin), increasing the risk of bleeding. Coagulation parameters (INR) should be monitored regularly, especially during dose adjustments.
Epilepsy: In rare cases, seizures have been reported when initiating levothyroxine therapy in patients with a known history of epilepsy. Careful monitoring is advised.
Osteoporosis risk: Long-term over-replacement with levothyroxine, leading to suppressed TSH levels, is associated with reduced bone mineral density, particularly in postmenopausal women. Regular monitoring of TSH and bone health assessments may be warranted.
Biotin interference: If you take biotin (vitamin B7/B8) — including in multivitamins or hair, skin, and nail supplements — inform your doctor before thyroid blood tests. Biotin can cause falsely elevated or falsely depressed thyroid hormone results depending on the assay used. Your doctor may advise stopping biotin supplements 2–3 days before laboratory testing.
Pregnancy and Breastfeeding
Pregnancy: Levothyroxine is safe and critically important during pregnancy. Adequate maternal thyroid hormone levels are essential for fetal brain development, especially during the first trimester before the fetal thyroid gland becomes functional. The dose requirement typically increases by 25–50% during pregnancy. TSH should be monitored every 4–6 weeks throughout pregnancy. The ATA recommends maintaining TSH levels below 2.5 mIU/L during the first trimester.
Important: During pregnancy, levothyroxine must not be combined with antithyroid drugs (thyrostatics). If hyperthyroidism coexists, only low-dose thyrostatic therapy should be used alone.
Breastfeeding: Levothyroxine can be safely used during breastfeeding. Small amounts of thyroid hormone are secreted into breast milk, but at physiological levels that do not affect infants with normal thyroid function. Continued thyroid hormone replacement during lactation is recommended.
Driving and Operating Machinery
Levothyroxine does not impair the ability to drive or operate machinery. Since it is identical to the naturally occurring thyroid hormone, it has no sedating or impairing effects when used at appropriate doses.
How Does Levothyroxine Interact with Other Drugs?
Quick Answer: Levothyroxine has numerous drug interactions that can either reduce its absorption or alter its effectiveness. Many common medications and supplements, including calcium, iron, and antacids, must be taken at least 2–4 hours apart from levothyroxine.
Drug interactions are one of the most clinically significant aspects of levothyroxine therapy. Because it has a narrow therapeutic index — meaning even small changes in blood levels can produce significant clinical effects — maintaining consistent absorption and metabolism is essential. Interactions can be broadly categorized into those that reduce absorption, those that alter metabolism, and those that change the body's response to either levothyroxine or the co-administered drug.
Medications That Reduce Absorption
The following medications and supplements bind to levothyroxine in the gastrointestinal tract and significantly reduce its absorption. They must be taken at least 2–4 hours apart from levothyroxine:
| Medication/Substance | Effect | Recommended Separation |
|---|---|---|
| Calcium supplements | Binds levothyroxine, reducing absorption by up to 40% | At least 4 hours |
| Iron supplements | Forms insoluble complex, reducing absorption significantly | At least 4 hours |
| Antacids (aluminum, magnesium) | Reduces absorption by binding in the stomach | At least 2 hours |
| Proton pump inhibitors (omeprazole, esomeprazole) | Reduces gastric acid, impairing dissolution and absorption | Monitor TSH; dose adjustment may be needed |
| Sucralfate | Binds levothyroxine in the GI tract | At least 2 hours |
| Cholestyramine / Colestipol | Bile acid sequestrants strongly bind levothyroxine | At least 4–5 hours |
| Sevelamer | Binds levothyroxine; used in dialysis patients | At least 4 hours |
Medications That Alter Levothyroxine Effect
Several medications alter the metabolism of levothyroxine or interact with thyroid hormone at the receptor level. When starting or stopping these medications, thyroid function should be monitored and levothyroxine dose adjusted as necessary:
- Carbamazepine, phenytoin, phenobarbital: These antiepileptic drugs increase the hepatic metabolism of levothyroxine, potentially reducing its effectiveness. Dose increases may be required.
- Rifampicin: Strongly induces hepatic enzymes, accelerating levothyroxine metabolism and potentially requiring dose increases.
- Estrogen-containing medications (hormone replacement therapy, oral contraceptives): Increase thyroxine-binding globulin (TBG) levels, which may increase levothyroxine requirements.
- Amiodarone: Contains a high iodine content and can cause both hypothyroidism and hyperthyroidism. Complex interaction requiring careful monitoring.
- Sertraline: May increase levothyroxine requirements through unclear mechanisms.
- Tyrosine kinase inhibitors (e.g., imatinib, sunitinib): Can increase levothyroxine requirements, particularly in patients without a functioning thyroid gland.
- Orlistat: May reduce levothyroxine absorption by binding to it in the GI tract. Close monitoring and dose adjustment may be needed.
- Propylthiouracil, glucocorticoids, beta-blockers: These inhibit the peripheral conversion of T4 to active T3, potentially affecting the clinical response to levothyroxine.
Levothyroxine's Effect on Other Drugs
- Antidiabetic medications: Levothyroxine may reduce the effectiveness of insulin and oral hypoglycemic agents, potentially requiring dose increases of diabetes medications. Monitor blood glucose closely, particularly when initiating or adjusting levothyroxine.
- Coumarin anticoagulants (warfarin): Levothyroxine enhances the anticoagulant effect of warfarin by increasing the catabolism of vitamin K-dependent clotting factors. INR monitoring and warfarin dose adjustment are essential.
Food Interactions
Soy products: Soy-based foods can reduce levothyroxine absorption from the intestine. If you regularly consume soy products, inform your doctor, as dose adjustments may be needed. Consistency in soy intake is more important than complete avoidance.
Coffee: Consuming coffee shortly after taking levothyroxine tablets can reduce absorption. Wait at least 30 minutes after taking the tablet before drinking coffee. The oral solution formulation may be less affected.
High-fiber diet: Very high dietary fiber intake can reduce levothyroxine absorption. Maintaining a consistent diet helps ensure stable thyroid hormone levels.
If you need to undergo imaging studies using iodine-containing contrast media, inform the radiologist and your prescribing physician that you take levothyroxine. Iodine-based contrast agents can temporarily affect thyroid function.
What Is the Correct Dosage of Levothyroxine?
Quick Answer: The dose of levothyroxine is highly individualized based on the patient's age, weight, the severity of hypothyroidism, and coexisting medical conditions. Most adults with hypothyroidism require between 50–200 mcg daily, with the dose adjusted based on TSH blood tests performed every 6–8 weeks.
Levothyroxine dosing is one of the most important aspects of treatment, as both under-dosing and over-dosing can have significant clinical consequences. The goal of therapy is to normalize TSH levels within the reference range (typically 0.4–4.0 mIU/L, although target ranges may vary based on individual factors). Doses are established through careful titration guided by laboratory monitoring and clinical assessment.
Adults
Standard Hypothyroidism Treatment
Starting dose: 25–50 mcg daily for most adults. Healthy younger adults without cardiac disease may start at a full replacement dose of 1.6 mcg/kg/day.
Titration: Increase by 25–50 mcg every 2–4 weeks until TSH is within target range.
Typical maintenance dose: 100–200 mcg daily (average 1.6 mcg/kg/day).
| Indication | Daily Dose | Notes |
|---|---|---|
| Hypothyroidism (maintenance) | 100–200 mcg | Individualized based on TSH levels |
| Goiter prevention (post-surgery) | 75–200 mcg | In patients with normal thyroid function |
| Benign goiter treatment | 75–200 mcg | Treatment duration: 6 months to 2 years |
| Thyroid cancer suppression | 150–300 mcg | Higher doses to suppress TSH to near-undetectable levels |
| Adjunct in hyperthyroidism | 50–100 mcg | Used with antithyroid drugs in block-and-replace regimens |
Children
Pediatric dosing depends on the child's age, weight, and the specific condition being treated:
Congenital Hypothyroidism (Newborns)
Starting dose: 10–15 mcg/kg/day during the first 3 months of life. Early initiation is critical for normal neurological development.
Monitoring: TSH and free T4 should be checked at 2 and 4 weeks after initiation, then every 1–2 months during the first year.
Acquired Hypothyroidism (Older Children)
Starting dose: 13–50 mcg daily, depending on age and weight.
Titration: Increase gradually every 2–4 weeks based on clinical response and laboratory results.
Elderly Patients
Elderly patients and those with cardiovascular disease require a cautious approach:
Elderly or Cardiac Patients
Starting dose: 12.5–25 mcg daily.
Titration: Increase by 12.5–25 mcg every 4–6 weeks with careful cardiac monitoring.
Rationale: Rapid correction of hypothyroidism can increase myocardial oxygen demand and precipitate cardiac events.
How to Take Levothyroxine
Proper administration is crucial for consistent absorption and therapeutic efficacy:
- Timing: Take the entire daily dose on an empty stomach in the morning, at least 30 minutes before breakfast
- Consistency: Take at the same time every day to maintain steady blood levels
- Tablets: Swallow with a full glass of water. Do not crush or chew unless specifically instructed
- Oral solution: Can be diluted in water, taken directly in the mouth, or administered via a spoon. Use immediately after opening the single-dose container
- Infants: The oral solution can be expressed into the inside of the cheek or onto a spoon. Do not mix with anything other than water
Missed Dose
If you forget a dose, do not take a double dose the next day. Simply skip the missed dose and resume your normal schedule the following day. Because levothyroxine has a long half-life (approximately 7 days), missing a single dose will have minimal impact on your overall thyroid hormone levels. However, consistent daily dosing is important for optimal therapy.
Overdose
Symptoms of levothyroxine overdose resemble those of hyperthyroidism (overactive thyroid) and may include: rapid heartbeat (tachycardia), palpitations, anxiety, agitation, tremor, sweating, fever, weight loss, diarrhea, muscle weakness, and insomnia. In severe cases, cardiac arrhythmias, chest pain, or seizures may occur. If you suspect an overdose, contact your doctor, go to the emergency department, or call your local poison control center immediately.
What Are the Side Effects of Levothyroxine?
Quick Answer: When dosed correctly, levothyroxine rarely causes side effects because it is identical to the body's own thyroid hormone. Most adverse effects result from excessive dosing (symptoms of hyperthyroidism) or allergic reactions to excipients. The risk of side effects is minimal with proper dosing and regular monitoring.
Levothyroxine is one of the most well-tolerated medications available because its active ingredient is chemically identical to the thyroid hormone naturally produced by the body. When the dose is correctly calibrated to achieve normal thyroid function (euthyroidism), side effects are negligible. However, symptoms can occur when the dose is too high (leading to iatrogenic hyperthyroidism) or in rare cases of hypersensitivity to the formulation ingredients.
If you experience any of the symptoms listed below, contact your healthcare provider. Your doctor will determine whether to temporarily discontinue the medication, reduce the dose, or investigate other causes.
Dose-Related Effects (Overdosage Symptoms)
Occur when dose exceeds individual requirements
- Rapid heartbeat (tachycardia), palpitations
- Cardiac arrhythmias
- Chest pain (angina pectoris)
- Elevated blood pressure
- Tremor, restlessness, agitation
- Insomnia, headache
- Excessive sweating, feeling of warmth
- Weight loss, increased appetite
- Diarrhea, nausea
- Muscle weakness, muscle cramps
- Menstrual irregularities
- Hair loss (usually temporary)
Rare / Hypersensitivity Reactions
Frequency not known — reported post-marketing
- Angioedema (swelling of face, lips, tongue, or throat)
- Skin rash
- Urticaria (hives)
Rare Neurological Effects
Very rare — mainly in specific patient populations
- Increased intracranial pressure with papilledema (particularly in children)
- Seizures in patients with known epilepsy history
- Fever
Unlike many medications that introduce foreign chemicals into the body, levothyroxine simply replaces a hormone that your body normally produces. When the dose is correctly matched to your body's needs, you should feel normal — not over-stimulated or under-treated. Regular blood tests (typically every 6–12 months once stable) help ensure your dose remains optimal.
Long-Term Considerations
Bone health: Chronic over-replacement (suppressed TSH) is associated with decreased bone mineral density, particularly in postmenopausal women. This risk is mainly relevant for patients on TSH-suppressive doses (e.g., after thyroid cancer). For patients on standard replacement therapy with TSH in the normal range, the risk to bone health is minimal.
Cardiac health: Prolonged excess thyroid hormone can increase the risk of atrial fibrillation and other cardiac arrhythmias, especially in elderly patients. Maintaining TSH within the appropriate target range minimizes this risk.
How Should You Store Levothyroxine?
Quick Answer: Store levothyroxine tablets at room temperature (below 25°C / 77°F), in the original packaging, protected from light and moisture. The oral solution has specific storage requirements after opening.
Proper storage of levothyroxine is important to maintain the medication's potency and effectiveness:
- Temperature: Store at or below 25°C (77°F). Avoid exposure to excessive heat or direct sunlight
- Packaging: Keep in the original packaging to protect from light
- Moisture: Store in a dry place. Avoid storing in the bathroom or near sinks
- Oral solution (single-dose containers): After opening the foil pouch, use the single-dose containers within 15 days. Once a single-dose container is opened, use immediately
- Expiry date: Do not use after the expiration date printed on the packaging
- Children: Keep out of sight and reach of children
- Disposal: Do not dispose of medications via the toilet or drain. Return unused medications to a pharmacy for proper disposal to protect the environment
What Does Levothyroxine Contain?
Quick Answer: The active ingredient in levothyroxine formulations is levothyroxine sodium, a synthetic form of the thyroid hormone T4. The inactive ingredients (excipients) vary by manufacturer and formulation.
Active ingredient: Levothyroxine sodium. This is the pharmacologically active substance that replaces the body's natural thyroid hormone. Levothyroxine sodium is a synthetic preparation that is chemically identical to the naturally occurring L-isomer of thyroxine.
Tablet formulations typically contain excipients such as lactose monohydrate, microcrystalline cellulose, calcium hydrogen phosphate, sodium starch glycolate, and magnesium stearate. The exact composition varies between manufacturers and brands (Levaxin, Euthyrox, Synthroid, and generic formulations).
Oral solution formulations (e.g., Tirosintsol) contain glycerol as the main excipient. These solutions contain less than 1 mmol (23 mg) sodium per 1 mL, making them essentially sodium-free. Single-dose containers are available in strengths from 13 to 200 mcg.
Because levothyroxine has a narrow therapeutic index, switching between different brands or between branded and generic formulations can sometimes lead to changes in thyroid hormone levels. If you switch products, your doctor should monitor your TSH levels 6–8 weeks after the change and adjust the dose if necessary. The ATA recommends that patients remain on a consistent formulation whenever possible.
Frequently Asked Questions About Levothyroxine
Levothyroxine is primarily used to treat hypothyroidism (underactive thyroid gland), a condition where the thyroid does not produce enough thyroid hormone. It is also used to prevent goiter recurrence after thyroid surgery, as TSH suppression therapy after thyroid cancer treatment, to treat benign goiter, and as an adjunct in hyperthyroidism management. It works by replacing the thyroid hormone thyroxine (T4) that your body normally produces.
The best time to take levothyroxine is in the morning on an empty stomach, at least 30 minutes before breakfast. This ensures optimal absorption from the gastrointestinal tract. Food, coffee, and other medications can significantly reduce absorption. Take it with a full glass of water and maintain a consistent daily routine for best results. If morning dosing is not practical, some studies suggest bedtime dosing (at least 3 hours after the last meal) may also be effective.
Taking too much levothyroxine causes symptoms of hyperthyroidism (overactive thyroid). These may include rapid or irregular heartbeat, anxiety, restlessness, tremor, sweating, weight loss despite increased appetite, diarrhea, and insomnia. Severe overdose can cause dangerous cardiac arrhythmias, chest pain, or in extreme cases, thyroid storm. If you suspect an overdose, stop taking the medication and seek immediate medical attention.
When used to treat hypothyroidism, levothyroxine may help restore normal weight by correcting the metabolic slowdown caused by thyroid deficiency. Patients typically lose a modest amount of weight (usually 2–5 kg) once thyroid levels normalize. However, levothyroxine is not a weight loss drug and should never be used for that purpose. In people with normal thyroid function, taking levothyroxine will not produce weight loss and can cause serious cardiovascular and metabolic side effects.
Yes, levothyroxine is safe and essential during pregnancy. Adequate maternal thyroid hormone is critical for fetal brain development, especially in the first trimester. Women with hypothyroidism typically need a 25–50% dose increase during pregnancy. TSH should be monitored every 4–6 weeks. The American Thyroid Association recommends keeping TSH below 2.5 mIU/L in the first trimester. Important: Levothyroxine must not be combined with antithyroid drugs during pregnancy.
Levothyroxine has a gradual onset of action. Some patients notice improvement in energy and mood within 1–2 weeks. However, it typically takes 4–6 weeks for the full therapeutic effect and for TSH levels to stabilize at the new dose. This is why thyroid function tests are performed 6–8 weeks after starting treatment or changing the dose. Complete resolution of all hypothyroid symptoms may take 2–3 months or longer.
References
This article is based on peer-reviewed medical literature, international clinical guidelines, and official drug information resources:
- Jonklaas J, Bianco AC, Bauer AJ, et al. Guidelines for the Treatment of Hypothyroidism: Prepared by the American Thyroid Association Task Force on Thyroid Hormone Replacement. Thyroid. 2014;24(12):1670-1751. doi:10.1089/thy.2014.0028
- Garber JR, Cobin RH, Gharib H, et al. Clinical Practice Guidelines for Hypothyroidism in Adults: Cosponsored by the American Association of Clinical Endocrinologists and the American Thyroid Association. Thyroid. 2012;22(12):1200-1235. doi:10.1089/thy.2012.0205
- Pearce SH, Brabant G, Duntas LH, et al. 2013 ETA Guideline: Management of Subclinical Hypothyroidism. Eur Thyroid J. 2013;2(4):215-228. doi:10.1159/000356507
- European Medicines Agency (EMA). Levothyroxine - Summary of Product Characteristics. EMA, 2024.
- British National Formulary (BNF). Levothyroxine sodium. NICE, 2025. Available at: bnf.nice.org.uk
- World Health Organization. WHO Model List of Essential Medicines – 23rd List. WHO, 2023.
- Alexander EK, Pearce EN, Brent GA, et al. 2017 Guidelines of the American Thyroid Association for the Diagnosis and Management of Thyroid Disease During Pregnancy and the Postpartum. Thyroid. 2017;27(3):315-389. doi:10.1089/thy.2016.0457
- Chaker L, Bianco AC, Jonklaas J, Peeters RP. Hypothyroidism. Lancet. 2017;390(10101):1550-1562. doi:10.1016/S0140-6736(17)30703-1
Editorial Team
This article has been written, reviewed, and approved by the iMedic Medical Editorial Team in accordance with international medical guidelines (ATA, ETA, WHO, BNF).
Licensed physicians with specialization in endocrinology, internal medicine, and clinical pharmacology. All content follows the GRADE evidence framework.
Independent review by board-certified endocrinologists ensuring accuracy, completeness, and adherence to current best practices and guidelines.
Evidence level: Level 1A — based on systematic reviews and meta-analyses of randomized controlled trials.
Conflicts of interest: None. iMedic receives no commercial funding and has no pharmaceutical industry affiliations.
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