Synthroid (Levothyroxine)

Name: Synthroid
Brand: BGP Pharma/Mylan
SKU: 6164
Availability: InStock

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Product

Manufacturer

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Dosage

Qty-Price (USD)

Type:

Product: Synthroid

Manufacturer: BGP Pharma/Mylan

Country: Canada

Dosage: 25 mcg

Qty-Price (USD):

Type:

Product: Synthroid

Manufacturer: BGP Pharma/Mylan

Country: Canada

Dosage: 50 mcg

Qty-Price (USD):

Type:

Product: Synthroid

Manufacturer: BGP Pharma/Mylan

Country: Canada

Dosage: 75 mcg

Qty-Price (USD):

Type:

Product: Synthroid

Manufacturer: BGP Pharma/Mylan

Country: Canada

Dosage: 88 mcg

Qty-Price (USD):

Type:

Product: Synthroid

Manufacturer: BGP Pharma/Mylan

Country: Canada

Dosage: 100 mcg

Qty-Price (USD):

Type:

Product: Synthroid

Manufacturer: BGP Pharma/Mylan

Country: Canada

Dosage: 112 mcg

Qty-Price (USD):

Type:

Product: Synthroid

Manufacturer: BGP Pharma/Mylan

Country: Canada

Dosage: 125 mcg

Qty-Price (USD):

Type:

Product: Synthroid

Manufacturer: BGP Pharma/Mylan

Country: Canada

Dosage: 137 mcg

Qty-Price (USD):

Type:

Product: Synthroid

Manufacturer: BGP Pharma/Mylan

Country: Canada

Dosage: 150 mcg

Qty-Price (USD):

Type:

Product: Synthroid

Manufacturer: BGP Pharma/Mylan

Country: Canada

Dosage: 175 mcg

Qty-Price (USD):

Type:

Product: Synthroid

Manufacturer: BGP Pharma/Mylan

Country: Canada

Dosage: 200 mcg

Qty-Price (USD):

Type:

Product: Synthroid

Manufacturer: BGP Pharma/Mylan

Country: Canada

Dosage: 300 mcg

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Generic Equivalent of Synthroid

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Type:

Product: Levothyroxine

Manufacturer: Generic

Country: Canada

Dosage: 25 mg

Qty-Price (USD):

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Product: Levothyroxine

Manufacturer: Generic

Country: Canada

Dosage: 50 mg

Qty-Price (USD):

Type:

Product: Levothyroxine

Manufacturer: Generic

Country: Canada

Dosage: 75 mg

Qty-Price (USD):

Type:

Product: Levothyroxine

Manufacturer: Generic

Country: Canada

Dosage: 88 mg

Qty-Price (USD):

Type:

Product: Levothyroxine

Manufacturer: Generic

Country: Canada

Dosage: 100 mg

Qty-Price (USD):

Type:

Product: Levothyroxine

Manufacturer: Generic

Country: Canada

Dosage: 112 mg

Qty-Price (USD):

Type:

Product: Levothyroxine

Manufacturer: Generic

Country: Canada

Dosage: 125 mg

Qty-Price (USD):

Type:

Product: Levothyroxine

Manufacturer: Generic

Country: Canada

Dosage: 137 mg

Qty-Price (USD):

Type:

Product: Levothyroxine

Manufacturer: Generic

Country: Canada

Dosage: 150 mg

Qty-Price (USD):

Type:

Product: Levothyroxine

Manufacturer: Generic

Country: Canada

Dosage: 175 mg

Qty-Price (USD):

Type:

Product: Levothyroxine

Manufacturer: Generic

Country: Canada

Dosage: 200 mg

Qty-Price (USD):

Type:

Product: Levothyroxine

Manufacturer: Generic

Country: Canada

Dosage: 300 mg

Qty-Price (USD):

Synthroid Information

medically reviewed by Carol Hou (BSc. Pharm) on May 5, 2025.

A licensed pharmacist (Licensed Community Pharmacies Directory | College of Pharmacists of British Columbia) with over 20 years of experience in medication management, specifically medication safety, she has reviewed the information for accuracy and completeness.

Synthroid and Levothyroxine at CanadaPharmacyonline.com

Synthroid (levothyroxine) is a brand name for levothyroxine sodium. In Canada, Synthroid is marketed by BGP Pharma, a Viatris company.

Currently, we do not carry a generic version of Synthroid at this pharmacy.

Dosage:

Brand Synthroid is available in 25 mcg, 50 mcg, 75 mcg, 88 mcg, 100 mcg, 112 mcg, 125 mcg, 137 mcg, 150 mcg, 175 mcg, 200 mcg, and 300 mcg tablets.

Your doctor will determine the appropriate dose based on your needs and medical conditions.

Usage:

Synthroid (levothyroxine sodium) is a prescription, synthetic thyroid hormone used to treat hypothyroidism in adults and children. It is meant to replace a hormone that is usually made by the thyroid gland. Synthroid is also used as part of the treatment plan for certain types of thyroid cancer, specifically thyrotropin-dependent well-differentiated thyroid cancer. After surgery and/or radioiodine therapy, Synthroid is given at doses that suppress the production of thyroid-stimulating hormone (TSH) from the pituitary gland. TSH can stimulate the growth of any remaining thyroid cancer cells, so suppressing it helps to prevent recurrence. (refer to the product monograph in Canada)

Thyroid replacement treatment is usually taken for life. Synthroid should not be used to treat noncancerous growths or enlargement of the thyroid in patients with normal iodine levels, or for inflammation of the thyroid gland.

Mechanism of Action:
Levothyroxine, the active ingredient in Synthroid, belongs to the class of medications called thyroid hormone replacement medications. It is a synthetic version of the thyroid hormone thyroxine (T4), which acts primarily as a prohormone. Levothyroxine is the standard treatment for hypothyroidism, working by supplementing or replacing deficient endogenous thyroid hormone levels. In the body, levothyroxine (T4) undergoes peripheral conversion, primarily in the liver and kidneys, as well as other tissues, to its primary biologically active form, triiodothyronine (T3). T3 then exerts its effects at a cellular level by binding to nuclear thyroid hormone receptors, influencing gene transcription and subsequent protein synthesis, thereby restoring normal physiological functions that are dependent on thyroid hormones.

Take Synthroid orally exactly as your doctor prescribes, following the instructions on the official prescribing information website. Consult your doctor for personalized guidance and safe use.

The information below summarizes some, but not all, potential side effects, risks, and interactions. Before taking Synthroid, it is essential to discuss all possible side effects, risks, and interactions with your doctor or pharmacist.

Side Effects

The information below outlines potential side effects associated with Synthroid. It is not an exhaustive list, and individual reactions can vary. Before starting Synthroid, it is crucial to discuss possible side effects and risks with your doctor or pharmacist. The side effects of Synthroid (levothyroxine) can range from mild to serious and can occur due to various factors, including dosage and individual sensitivity. The categorization of side effects provided below is based on general observations.

Common Side Effects (often related to taking too much medication and mimicking hyperthyroidism):
• Changes in menstrual periods can occur, including irregular bleeding, and changes in flow (lighter or heavier);
• Diarrhea, nausea, vomiting (changes in appetite can occur. Increased appetite is more commonly a sign of over-treatment (mimicking hyperthyroidism), while decreased appetite is more typical of untreated hypothyroidism;
• Fast or irregular heartbeat (palpitations), increased heart rate, chest pain (angina);
• Hair loss (often temporary and can occur during the initial months of treatment or with significant dosage changes);
• Muscle weakness or spasms;
• Nervousness, anxiety, irritability, tremors, difficulty sleeping (insomnia), headache;
• Weight loss, increased appetite, heat intolerance, excessive sweating

Less Common Side Effects:
• Joint pain (can occur);
• Shortness of breath (dyspnea), especially with exertion;
• Skin rash, itching (pruritus), or hives (urticaria)

Rare but Serious Side Effects:
• Allergic reactions may include skin rash, itching, hives, swelling of the face, lips, tongue, or throat (angioedema), and shortness of breath;
• Effects on Growth and Development in Children:
• Early closure of fontanelles in infants.
• Premature fusion of epiphyses (growth plates) in children, potentially leading to decreased adult height.
• Heart attack;
• Increased pressure inside the skull (pseudotumor cerebri - symptoms can include headache, blurred vision, and sometimes vomiting);

Long-Term Side Effects:
• Cardiovascular Risks (long-term use, especially at higher doses, may increase the risk of heart problems, particularly in older adults or those with pre-existing heart conditions);
• Decreased Bone Mineral Density (long-term treatment can lead to increased bone loss and a higher risk of fractures, especially in post-menopausal women);
• Worsening of Diabetes Control (Synthroid can affect blood sugar levels, potentially making it harder to manage diabetes);

Contraindications:

The following is not an exhaustive list of contraindications. Before starting Synthroid, it is crucial to discuss all your medical conditions, past and present, and all medications you are taking with your doctor or pharmacist.

Synthroid should not be used if you:
• Are allergic to any of the inactive ingredients in Synthroid;
• Have Acute Myocardial Infarction (Heart Attack): Synthroid can put extra stress on the heart. It is generally avoided in the immediate period following a heart attack;
• Have Acute Myocarditis or Pericarditis (Inflammation of the Heart): Similar to a recent heart attack, Synthroid can exacerbate these conditions;
• Have Active Cardiac Arrhythmias (Irregular Heartbeats): Synthroid can increase heart rate and potentially worsen existing arrhythmias.
• Have Thyrotoxicosis (High Levels of Thyroid Hormone): Synthroid is a thyroid hormone replacement and should not be used when there is already an excess of thyroid hormone in the body.
• Have Untreated Adrenal Insufficiency: Synthroid can increase the body's need for cortisol. If adrenal insufficiency (a condition where the adrenal glands don't produce enough cortisol) is not treated, taking Synthroid may lead to an acute adrenal crisis.

Tell your doctor about all of your medical conditions, past and present, before starting Synthroid. This is crucial because certain conditions can affect whether Synthroid is right for you. These conditions may include, but are not limited to:
• Cardiovascular Disease: Patients with heart conditions, especially the elderly, are at an increased risk of adverse cardiovascular effects such as increased heart rate, angina, and arrhythmias. Synthroid should be initiated at a lower dose with careful monitoring.
• Diabetes Mellitus: Synthroid may worsen glycemic control, requiring adjustments in diabetes medication dosage. Blood sugar levels should be monitored closely
• Osteoporosis or other Bone Conditions: Synthroid may decrease bone mineral density, especially in post-menopausal women on higher doses.
• Patients with Secondary or Tertiary Hypothyroidism: Other pituitary or hypothalamic hormone deficiencies may need to be addressed concurrently.

Drug Interactions:

Before taking Synthroid, it is essential to discuss all potential risks and interactions with your doctor or pharmacist. For complete and up-to-date information, refer to the product labeling information, https://www.accessdata.fda.gov/drugsatfda_docs/label/2017/021402s024s028lbl.pdf.

Provide your doctor with a complete list of all your medications, including prescriptions, over-the-counter (OTC) drugs, vitamins, and herbal supplements. Many medications, supplements, and certain foods can interact with Synthroid by affecting its absorption or the body's response to it.

Medications that can decrease Synthroid absorption:
• Antacids (containing aluminum, calcium, or magnesium);
• Bile acid sequestrants;
• Calcium supplements;
• Iron supplements;
• Phosphate binders (lanthanum, sevelamer);
• Proton pump inhibitors (PPIs);
• Sucralfate

Medications that can affect Synthroid's effectiveness or the effectiveness of other drugs:
• Androgens/anabolic steroids;
• Beta-blockers (e.g., propranolol) can have their effectiveness altered by thyroid hormone levels. Thyroid replacement therapy might necessitate adjustments in beta-blocker dosage.
• Certain antidepressants (tricyclic antidepressants, SSRIs) can have their effectiveness and potential side effects influenced by thyroid hormone levels. Careful monitoring and potential dosage adjustments may be required.
• Digoxin;
• Estrogen-containing medications (e.g., birth control pills, hormone replacement therapy);
• Insulin and oral diabetes medications;
• Phenytoin, Carbamazepine, Phenobarbital;
• Rifampin;
• Sympathomimetics (e.g., albuterol, pseudoephedrine) can have increased cardiovascular effects when taken with thyroid hormones;
• Warfarin (blood thinner)

Supplements that can affect Synthroid absorption:
• Calcium-containing supplements;
• Iron-containing supplements;
• Magnesium-containing supplements;
• Multivitamins with minerals (separate by at least 4 hours)

Foods and Beverages that can affect Synthroid absorption: (Be consistent with the timing of your dose relative to meals. Avoid taking Synthroid within 4 hours of medications or supplements that can interfere with its absorption.)
• Coffee (Coffee can affect Synthroid absorption. It is generally recommended to take Synthroid at least 30 to 60 minutes before consuming coffee);
• Cottonseed meal
• Dairy products (Dairy products can affect Synthroid absorption due to their calcium content. It is generally recommended to separate their intake from Synthroid by several hours (e.g., 2-4 hours);
• Grapefruit and grapefruit juice;
• High-fiber foods;
• Soybeans, soybean flour, or soy-based infant formula;
• Walnuts

Pregnancy and Breastfeeding:

Synthroid is generally safe and often necessary during pregnancy and breastfeeding for women with hypothyroidism. Close monitoring of thyroid hormone levels and appropriate dosage adjustments by your healthcare provider are essential to ensure the well-being of both the mother and the baby.

Elderly Patients:

Synthroid is a crucial medication for treating hypothyroidism in elderly patients. However, due to their increased sensitivity and the higher prevalence of comorbidities, particularly cardiovascular issues, treatment must be initiated at a low dose, titrated slowly, and monitored carefully. The goal is to achieve and maintain a normal thyroid hormone level without causing adverse effects. It is essential for elderly patients to have regular check-ups with their doctor to monitor their thyroid function and adjust their Synthroid dosage as needed.

Frequently Asked Questions about Synthroid at Canada Pharmacy Online:

Why is Synthroid more affordable in Canada than in the United States?

Prescription drug prices, including Synthroid, are generally lower in Canada than in the US due to a combination of factors, primarily government price regulations, differing market dynamics, and other economic considerations. In Canada, provincial and federal governments negotiate drug prices with pharmaceutical companies, which often results in lower costs compared to the U.S., where market forces play a more significant role. For more information, see the FAQs on Prescription Drug Importation from the Kaiser Family Foundation (KFF): https://www.kff.org/health-costs/issue-brief/faqs-on-prescription-drug-importation/

What is the difference between Synthroid 25 mcg and 100 mcg?

The difference in dosage represents the amount of active ingredient(s) present in the drug.

How much is the shipping?

Our shipping fee is a flat rate of $10.00 per order. Our pharmacy focuses on offering you the lowest prices on high-quality products.

How do I order from your pharmacy?

Ordering from us is very simple. You can purchase online or call Customer Service at 1866.920.3784; for more information or to learn about the ordering process, visit our How to Order page.

Is there a limit on how many tablets I am allowed to order at one time?

CanadaPharmacyOnline.com can only dispense a maximum of a three-month supply of Synthroid at once, per your doctor's prescription.

Can I buy over the counter from you?

No, Synthroid requires a valid prescription from your doctor. We do not sell this product without a valid prescription.

Do you ship to the United States?

Yes, we do. It usually takes 7 to 18 business days to receive your order from our pharmacy.

Can I stop taking Synthroid if I feel better?

Generally, you should not stop taking Synthroid without consulting your doctor, as hypothyroidism is often a chronic condition, and discontinuing the medication can lead to a return of symptoms and potentially serious health complications. In some cases of borderline or subclinical hypothyroidism, a doctor may consider a trial period off medication, but this should only be done under strict medical supervision. Abruptly stopping Synthroid can lead to the return of hypothyroid symptoms and may even cause more severe issues like heart problems or myxedema coma in rare cases.

When is the best time to take Synthroid tablets?

The optimal way to take Synthroid is generally on an empty stomach to maximize absorption. While the morning, 30 to 60 minutes before breakfast, is a common and often recommended time, it can also be taken at bedtime, at least 3 hours after the last meal, if that better suits an individual's lifestyle. Consistency in timing each day is crucial for maintaining stable thyroid hormone levels. Certain medications and supplements (like iron and calcium) can interfere with Synthroid absorption and should be taken at least 4 hours apart.

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The information on this page is sourced from independent third parties contracted by CanadaPharmacyOnline. While we cannot guarantee its medical accuracy, we strongly recommend consulting a healthcare professional for personalized advice regarding medications or medical conditions.

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