Levothyroxine Tablets for Hypothyroidism, Comparable to Synthroid®

What Levothyroxine Is and How It Works

Levothyroxine is a synthetic form of thyroxine (T4) used to treat hypothyroidism. These levothyroxine tablets restore circulating thyroid hormone so tissues can normalize metabolism. Levothyroxine is taken by mouth once daily and is available in many strengths to support precise dosing. Patients often switch from a brand such as Synthroid to generic, and dose is adjusted based on TSH.

YouDrugstore is a licensed Canadian pharmacy headquartered in Manitoba; prescriptions are reviewed by licensed pharmacists before dispensing. We also partner with licensed, vetted international pharmacies to source authentic brand medicines, keep a broad selection in stock, and maintain affordable pricing.

Common strengths include levothyroxine 25 mcg tablets, levothyroxine 50mcg tab, levothyroxine sodium 75 mcg, levothyroxine 88 mcg tab, and levothyroxine 100. Options also include levothyroxine 112 mcg tablet and levothyroxine 137 mcg. The dose is individualized. A clinician reviews TSH and clinical response, then adjusts by small increments.

Levothyroxine replaces missing thyroid hormone in primary hypothyroidism (for example, Hashimoto’s), after thyroid surgery, or after radioactive iodine. It is also used to suppress TSH in certain thyroid nodules or goitre. These thyroid hormone tablets are not for weight loss and should not be combined with other drugs for that purpose.

Dosage and Usage

• Typical initiation: lower doses are used in older adults or in cardiac disease. Many otherwise healthy adults require gradual titration.
• Common titration steps: 12.5–25 micrograms every 4–6 weeks, guided by TSH.
• Common maintenance strengths include levothyroxine sodium 25 mcg, levothyroxine sodium 50 mcg, 100 mcg of levothyroxine, and 150 micrograms. Dose precision helps achieve a stable TSH.
• Usual dose of levothyroxine for full replacement is often near 1.6 mcg/kg/day. Actual needs vary by age, weight, pregnancy, and comorbidities.
• Administration: the dose is taken once daily on an empty stomach with water, at the same time each day.
• Avoid interacting agents for at least 4 hours after the dose. This includes calcium, iron, magnesium, cholestyramine, and some multivitamins.
• Consistency matters. Switching between products can affect levels. Clinicians often recheck TSH after any product change.
• Missed dose: take when remembered that day. If near the next dose, skip the missed dose. Do not double doses.
• Lab monitoring: TSH is usually checked 4–6 weeks after any dose change. Stable patients are typically monitored every 6–12 months.
• Not for weight loss alone. Combining thyroid hormone with other drugs to reduce weight can cause serious harm.

• Storage: keep your tablets at 20–25°C (68–77°F), protected from moisture and light.
• Bottle care: close the cap tightly and leave desiccants in the container if present.
• Travel: carry your medication in original packaging in your carry-on. Bring your prescription.
• Heat and cold: avoid storing your medicine in a glovebox or near heaters. Do not freeze.
• Daily routine: use a pill organizer if it helps your schedule, and pack extra doses for trips.
• Refills: set reorder reminders so you do not run out during travel.

Benefits and Savings

Levothyroxine supports steady symptom relief once levels stabilize. Many patients report improved energy, less cold intolerance, and better cognition as dosing reaches goal. Once-daily dosing is simple, and a wide range of strengths helps fine-tune therapy. Tablets are small, and most are dye-coded by strength for easy identification.

Buying from Canada can cut costs meaningfully. You can often save 60–80% compared with typical US prices, especially on multi-month supplies. Choosing a larger quantity can lower the per-month cost, and reorder reminders help you stay on schedule. Some patients prefer brand; others select generic to reduce expense.

Side Effects and Safety

• Common effects when over-replaced: palpitations, nervousness, tremor, heat intolerance, sweating, and insomnia.
• Common effects when under-replaced: fatigue, cold intolerance, constipation, and dry skin.
• Other effects: transient hair thinning early in therapy, headache, irritability, and muscle weakness.
• Allergy or intolerance: sensitivity to tablet dyes or fillers is uncommon but possible.

Serious risks are uncommon at correct doses. Excess thyroid hormone can worsen angina, cause arrhythmias, or lower bone density with long-term overtreatment. Levothyroxine is contraindicated in untreated thyrotoxicosis and uncorrected adrenal insufficiency. Pregnancy usually increases dose needs; clinicians monitor TSH more closely during pregnancy and postpartum.

Onset Time

Many people notice symptom improvements within 1–2 weeks of starting or adjusting therapy. TSH usually takes 4–6 weeks to reflect dose changes because of hormone half-life. The goal is a stable TSH and symptom control after dose titration. Weight and fluid changes may normalize gradually as euthyroidism returns.

Compare With Alternatives

Brand levothyroxine, such as Synthroid®, offers consistent performance and a standardized dye schedule by strength. Many patients do well on generic levothyroxine tablets at lower cost. If the product changes, clinicians often recheck TSH and adjust as needed.

Liothyronine (T3) can be used in select cases, often short term or in combination. Combination T4/T3 regimens are individualized and require careful monitoring because T3 has a faster onset and higher peak effects.

Desiccated thyroid is less standardized and can vary in T3/T4 content. Many guidelines prefer levothyroxine because it provides stable T4 for physiologic conversion to T3.

For hyperthyroidism symptom control, beta blockers such as Tenormin® may reduce tremor and heart rate while definitive therapy proceeds. These agents are not alternatives to levothyroxine for hypothyroidism but are part of the broader thyroid care landscape.

To learn more about thyroid options and brand versus generic considerations, see our overview in Generics Vs Brand Name Medications and our guide to Thyroid Drugs.

Combination Therapy

• Levothyroxine plus liothyronine: used selectively; doses are reduced to avoid overtreatment and palpitations.
• Levothyroxine with iron or calcium: separate by at least 4 hours to avoid reduced absorption.
• Levothyroxine with acid suppressants: some PPIs may affect absorption; TSH monitoring guides any adjustments.
• Bile acid sequestrants (cholestyramine/colesevelam): separate dosing times widely to prevent binding.
• Consistency: keep the same brand or generic where possible; recheck TSH after any product change.

Patient Suitability and Cost-Saving Tips

Candidates include adults and children with primary or secondary hypothyroidism, post-thyroidectomy patients, and those needing TSH suppression for select thyroid nodules. Non-candidates include those with uncorrected adrenal insufficiency or active thyrotoxicosis. Caution is needed in coronary artery disease and in older adults, where lower starting doses are common.

Pregnancy often increases requirements; frequent TSH checks help maintain target levels for maternal and fetal health. Breastfeeding is generally compatible. People with osteoporosis risk benefit from avoiding chronic overtreatment. Those sensitive to dyes may choose specific strengths with minimal colorants or dye-free options where available.

To manage costs, consider multi-month orders to lower the per-month price. Set reorder reminders so you do not miss a dose while waiting for a shipment. Staying on a consistent product can limit extra lab visits after a switch. If brand is preferred, compare options and discuss any previous response to specific products.

For more background on thyroid conditions and therapies, you can review Hypothyroidism, Goitre, and Thyroid Disease resources in our library.

Authoritative Sources

Synthroid official product information

Health Canada Drug Product Database: levothyroxine listings

FDA Prescribing Information: Levothyroxine sodium tablets

Order Levothyroxine from YouDrugstore: add to cart, upload your prescription, and we ship with prompt, express service.

This material is educational and does not replace advice from your healthcare professional. Always follow the guidance of your prescriber and pharmacist.