Can You Take Expired Levothyroxine?

In our latest question and answer, the pharmacist discusses the safety of using expired levothyroxine.

Question

Can levothyroxine be taken safely up to 4 months after the expiration date?

Asked by Camilla On Apr 22, 2021

Answered by
Medical Content Reviewed By HelloPharmacist Staff

Published Apr 22, 2021
Last updated Mar 29, 2024

Key points

  • It is not recommended to take expired drugs, include expired levothyroxine.
  • Expired drugs may lost potency over time, and may not treat your condition appropriately.

Thanks for reaching out to us!

Synthroid (levothyroxine) is a synthetic thyroid hormone (T4) and is the most prescribed drug used to treat hypothyroidism. It is important to take it as directed to effectively treat your low thyroid levels.

As a general rule of thumb, you should not take expired medications, including expired levothyroxine, as it may not be as potent as it once was. If at all possible, see your doctor or pharmacy for a new prescription.

When Does Levothyroxine Expire?

After manufacture, levothyroxine typically has an expiration date of 18-24 months once it reaches your local pharmacy.

Once a pharmacy dispenses it, they generally will put an expiration date of either one year or the actual expiration date on the bottle (whichever is soonest). It’s standard practice for pharmacies to list an expiration date of one year after dispensing due to the fact that you may not keep the drug stored in a controlled environment like your local pharmacy (i.e. things like excess moisture and heat can affect the long-term stability of drugs).

Now, levothyroxine is a synthetic hormone.

In general, hormones are a bit more unstable than most other medications. They are particularly susceptible to degrading and have a shorter shelf life than most other medications in the pharmacy (though it wouldn’t be apparent just from looking at it).

Safety Concerns With Expired Levothyroxine

If your levothyroxine has degraded and began to lose potency, you would only get a partial dose of the stated strength of the drug. This partial dose might be ineffective, and may not adequately treat your hypothyroidism.

It is dosed in such small amounts (micrograms) that there is quite a high likelihood that even a very small change in dose (perhaps from drug degradation if it's expired) can make a huge difference in how the drug works for you.

As an overall concept, it’s not a good idea to take that expired levothyroxine or any expired drug for that matter. You just don't know if it has lost some potency over time, and there is no easy way to check.

I’d recommend throwing it away and contacting your physician. If you have been seen recently, I’m sure that they would be willing to call in your current dose. If you haven’t, it seems like a good opportunity to get a correct dose from your baseline thyroid function.

If you haven't been seen recently, your physician or primary care provider may need to evaluate your thyroid blood levels to determine the proper dose of levothyroxine for you, before sending a new prescription in.

Final Words

So, again, dosing levothyroxine is already difficult due to the fact that a precise dose is required. Using potentially expired levothyroxine will only complicate things further. Get a new prescription that is in-date.

I hope this helps and you get a chance to see your dentist soon! Feel free to write us again in the future.

References

About the Pharmacist

Dr. Brian Staiger, PharmD

Dr. Brian has been practicing pharmacy for over 13 years and has wide-ranging experiences in many different areas of the profession. From retail, clinical, program development, and administrative responsibilities, he's your knowledgeable and go-to source for all your pharmacy and medication-related questions! Dr. Brian Staiger also has herbalist training and educational certificates in the field of medical ethnobotany. Feel free to send him an email at [email protected]! You can also connect with Dr. Brian Staiger on LinkedIn.

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