Thousands of 5-Star Reviews From Real Customers - Find Out Why Our Customers Love Us Here!
Canadian Med Center

Exploring Generic Synthroid: Is It Right for You?

Friday 14 June 2024
5 minute(s) read

Table of Contents

I. What is Generic Synthroid?

II. Effectiveness of Synthroid vs Levothyroxine

III. Switching from Synthroid to Levothyroxine

IV. Levothyroxine Cost

V. Conclusion

When it comes to choosing between Synthroid vs. levothyroxine for hypothyroidism treatment, your healthcare provider likely has good reason for recommending one over the other based on your medical history. Though research doesn't indicate that brand name Synthroid is more effective than the generic levothyroxine, studies do show that sticking with one formulation consistently is key to treating hypothyroidism. [1]

In this article, we will provide an overview of Synthroid and generic levothyroxine, compare them in terms of effectiveness and cost, and discuss why consistency and compliance with your medication are so important for managing hypothyroidism.

What is Generic Synthroid?

Levothyroxine and Synthroid are considered first-line treatments for hypothyroidism. While these drugs may have different names, they contain the same active ingredient: levothyroxine. [1]

  • Levothyroxine is the generic medication
  • Synthroid is the brand-name medication

The brand name Synthroid was originally developed and patented by the pharmaceutical company AbbVie. [2] After the patent expired, other companies were able to manufacture generic levothyroxine. Even though the inactive ingredients in the tablets may differ between the brand and generic, both types contain the same formulation of the active ingredient, levothyroxine. [3]

Effectiveness of Synthroid vs Levothyroxine

pharmaceutical researchers working

When it comes to treating hypothyroidism, both generic levothyroxine and brand-name Synthroid are intended to work equally well. The active ingredient is the same in both versions.

A large study looking at over 17,000 patients taking either generic or brand-name levothyroxine found that the percentage who reached normal thyroid hormone levels within three months was nearly identical. This suggests the generic is just as effective for most. [4]

While this research is reassuring, it's important to remember that everyone's body can respond differently to medication. The inactive ingredients in generic and brand-name drugs, though not medically active themselves, can sometimes affect how your body absorbs the medication. So, if you don't feel your symptoms are improving on a generic levothyroxine, talk to your doctor. They may recommend trying Synthroid or another brand-name option to see if it works better for you. [5]

Switching from Synthroid to Levothyroxine

doctor talking to a patient

While generic levothyroxine and brand name Synthroid contain the same active ingredient (levothyroxine sodium), the inactive ingredients used in the formulations differ.

  • Active ingredients are medication components that provide the intended therapeutic effect. For Synthroid and levothyroxine, the active ingredient is levothyroxine sodium, which replaces the thyroid hormone for people with hypothyroidism.
  • Inactive ingredients do not directly influence the therapeutic effects. Rather, they allow the active ingredients to be effectively absorbed and broken down in the body. [6]

While inactive ingredients are not the main therapeutic component, variations can impact how quickly the medication is absorbed and how the body responds. Even minor differences in inactive ingredients between brand name and generic thyroid medications could lead to noticeable changes in thyroid hormone levels. This means switching between Synthroid and generic levothyroxine, or between different generic manufacturers, may alter your hormone levels. [7]

In general, if you stick with the same brand name or generic medication from the same manufacturer, the inactive ingredients should remain consistent. However, it's important to note that different companies produce generic levothyroxine. Therefore, it's advisable to check with your pharmacy to see which manufacturer they source the drug from and try to remain consistent with that brand. [7]

Neither brand name nor generic levothyroxine is inherently better. The most important thing is finding a formulation that works for you and maintaining consistency. If you do switch brands or manufacturers, get your thyroid stimulating hormone (TSH) retested in about six weeks to ensure your hormone levels remain in the proper range. You may need a dosage adjustment to account for any differences in the new product. [8]

Levothyroxine Cost

When it comes to most medications, the choice between generic and brand-name versions is not always significant. The FDA ensures that both options contain the same active ingredients, work in the same way, and have the same side effects. Additionally, generic medicines are often more affordable, making them a popular choice for many individuals. [3]

For example, the out-of-pocket cost for a 30-day supply of

  • Levothyroxine 75 mcg is around $35
  • Synthroid 75 mcg is upwards of $500

In the United States, your insurance plan may require your pharmacist to switch your brand name thyroid medication to a generic alternative, unless otherwise specified by your healthcare provider. However, when it comes to thyroid medications like Synthroid, transitioning between brand-name and generic versions requires careful consideration. Even slight differences in your medication can significantly impact your thyroid hormone levels, making it crucial to select a specific formulation and remain consistent with it. [7]

If you notice that you respond better to brand-name Synthroid, you have the option to save up to 50% on the annual cost by ordering from an online Canadian pharmacy such as Canadian Med Center. This substantial savings is achievable because prescription drug prices in Canada are regulated by the government to ensure affordability. [9] By ordering from an online Canadian pharmacy, these reduced drug costs can be passed on to American consumers, offering significant financial relief to those who rely on lifelong thyroid hormone replacement therapy.


Discussing Synthroid vs levothyroxine with your doctor is an important step in managing hypothyroidism. While generic levothyroxine and brand-name Synthroid both effectively replace the thyroid hormone your body lacks, your doctor may have valid reasons for recommending one over the other. Open communication with your doctor allows you to understand their rationale and make the best decision for your health.

If you do switch from Synthroid to generic levothyroxine, be sure to monitor your symptoms and get your thyroid hormone levels rechecked. Though they contain the same active ingredient, the inactive ingredients differ between brand-name and generic drugs. This means your body may absorb the generic slightly differently. Your doctor can ensure your hormone levels stay in the optimal range by making dosage adjustments as needed.

The information provided is for informational purposes only. We do not offer medical advice. Please consult with your physician or qualified healthcare professional for guidance on drugs, medical conditions, or treatments. Our content is not a replacement for professional medical recommendations.