Levothroid is a prescription medication containing levothyroxine sodium, a synthetic form of the thyroid hormone thyroxine (T4). It is specifically formulated to address hypothyroidism, a condition characterized by an underactive thyroid gland that fails to produce sufficient hormones. By supplementing the body with a bioidentical hormone, Levothroid helps normalize metabolic processes, energy production, and overall endocrine function. This therapy is designed for long-term management, requiring consistent use and regular monitoring by a healthcare professional to ensure optimal dosing and therapeutic efficacy.

Features

• Contains levothyroxine sodium, a synthetic version of endogenous T4 hormone
• Available in multiple strengths for precise dosage titration (e.g., 25 mcg, 50 mcg, 75 mcg, 88 mcg, 100 mcg, 112 mcg, 125 mcg, 137 mcg, 150 mcg, 175 mcg, 200 mcg)
• Manufactured under strict quality control to ensure consistent potency and purity
• Typically supplied as oral tablets, with clear scoring for accurate splitting if needed
• Formulated for high bioavailability and predictable absorption when taken as directed

Benefits

• Normalizes thyroid hormone levels, reversing the symptoms of hypothyroidism such as fatigue, weight gain, and cold intolerance
• Supports healthy metabolic rate, aiding in energy restoration and weight management
• Improves cognitive function, including memory, focus, and mood stability
• Promotes cardiovascular health by helping regulate heart rate and cholesterol levels
• Enhances overall quality of life by addressing the root hormonal deficiency
• Prevents long-term complications of untreated hypothyroidism, such as goiter or myxedema

Common use

Levothroid is primarily indicated for the treatment of hypothyroidism, whether due to autoimmune thyroiditis (Hashimoto’s disease), surgical thyroid removal, or radioactive iodine therapy. It is also used as thyroid replacement therapy in cases of congenital hypothyroidism. Additionally, it may be prescribed as suppressive therapy to prevent recurrence of thyroid nodules or thyroid cancer, though this requires careful supervision due to the risk of iatrogenic hyperthyroidism.

Dosage and direction

Dosage is highly individualized based on the patient’s age, weight, clinical condition, and thyroid function test results (e.g., TSH levels). The typical starting dose for healthy adults under 50 is 1.6 mcg/kg body weight per day, adjusted at 6–8 week intervals until euthyroidism is achieved. Administer Levothroid orally once daily, on an empty stomach, at least 30–60 minutes before breakfast. Tablets should be taken with a full glass of water; do not crush or chew. Consistency in timing and conditions of administration is critical to maintain stable hormone levels.

Precautions

• Regular monitoring of thyroid function tests is essential to avoid under- or overdosing
• Use with caution in patients with cardiovascular disease, as rapid correction may exacerbate angina or arrhythmias
• Elderly patients and those with long-standing hypothyroidism may require lower initial doses to avoid adverse cardiac effects
• Not recommended for use in obesity treatment or weight loss in euthyroid patients
• Pregnancy and lactation require dose adjustments; thyroid demands increase during gestation
• Inform healthcare providers of all concomitant medications, as many can affect absorption or metabolism

Contraindications

• Untreated subclinical or overt hyperthyroidism
• Uncorrected adrenal insufficiency
• Recent myocardial infarction, acute myocarditis, or acute pancarditis
• Known hypersensitivity to levothyroxine sodium or any excipients in the formulation
• Should not be used for the treatment of obesity or weight loss in patients with normal thyroid function

Possible side effect

Most side effects are dose-related and indicative of excessive dosing (i.e., hyperthyroidism). Common reactions may include:

• Palpitations, tachycardia, arrhythmias
• Headache, insomnia, nervousness, irritability
• Increased appetite, weight loss, diarrhea
• Heat intolerance, fever, excessive sweating
• Menstrual irregularities
• Muscle weakness, tremors
• Temporary hair loss during initial months of treatment (usually self-limiting)

Drug interaction

Levothroid has numerous potential drug interactions that may alter its efficacy or safety profile:

• Antacids, calcium carbonate, iron supplements, sucralfate: reduce absorption; separate administration by at least 4 hours
• Estrogens and oral contraceptives: may increase thyroxine-binding globulin, necessitating dose adjustment
• Warfarin: levothyroxine may potentiate anticoagulant effect
• Insulin/oral hypoglycemics: thyroid hormone may affect glycemic control
• Ketamine: may produce marked hypertension and tachycardia
• Tricyclic antidepressants: mutual potentiation of therapeutic and toxic effects
• Sevelamer, cholestyramine: bind levothyroxine; administer at least 4 hours apart

Missed dose

If a dose is missed, take it as soon as remembered on the same day. If it is nearly time for the next dose, skip the missed dose and resume the regular schedule. Do not double the dose to make up for a missed one. Consistency is important, but occasional missed doses are unlikely to cause significant disruption if the overall regimen is maintained.

Overdose

Symptoms of overdose are those of hyperthyroidism: tachycardia, arrhythmias, chest pain, tremors, headache, insomnia, sweating, fever, heat intolerance, weight loss, and diarrhea. In severe cases, thyroid storm may occur, which is a medical emergency. Treatment is supportive and symptomatic; beta-blockers may be used to control adrenergic symptoms. Reduce or withhold levothyroxine until symptoms resolve, then reinstitute at a lower dose.

Storage

Store Levothroid tablets at controlled room temperature (20°–25°C or 68°–77°F), in a dry place, protected from light and moisture. Keep the bottle tightly closed. Do not store in bathrooms or near sinks. Keep out of reach of children and pets. Do not use beyond the expiration date printed on the packaging.

Disclaimer

This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition or medication. Do not disregard professional medical advice or delay in seeking it because of something you have read here. Dosage and usage must be determined by a healthcare professional based on individual patient needs.

Reviews

(Note: Actual patient reviews should be sourced from verified platforms and monitored by healthcare providers. The following represents common themes from clinical experience.)

• “After starting Levothroid, my energy levels returned to normal within weeks. The brain fog lifted, and I feel like myself again.”
• “Dose adjustments were necessary initially, but with regular blood tests, my doctor found the right balance. I’ve been stable for years now.”
• “Taking it first thing in the morning on an empty stomach made a noticeable difference in consistency of effect.”
• “Be patient—it takes time to titrate correctly, but the improvement in quality of life is worth it.”
• “I experienced some hair shedding during the first few months, but it resolved as my body adjusted.”