expired synthroid

[Mccrae]

I need solid information about expired synthroid? My synthroid expired 12 days and I didn’t realize. My endo claims that it doesn’t expire. However some pharmacies agree and some don’t. Does synthroid lose 100 percent potency after expiring?

[helvella Administrator]

In the UK, expiry dates are shown as a month (e.g. 04/2023). And the text expressly states that this is to be taken as the last day of that month.

Synthroid (and other levothyroxine tablets) will likely have an expiry date set from 18 months to three years after manufacture - depending on agreement between manufacturer and FDA or other official body. It simply cannot suddenly lose 100% overnight!

Expiry dates identify the date to which the product must remain within the official range of potency - in the USA, that is 95 to 105% of potency.

Whether you have stored it sensibly is the single most important factor.

There is a very brief section of my Vade Mecum which discusses this issue.

Expiry Dates

helvella's Vade Mecum document is available here:

helvella - Vade Mecum for Thyroid

The term vade mecum means:

1. A referential book such as a handbook or manual.

2. A useful object, constantly carried on one’s person.

helvella.blogspot.com/p/hel...

[Mccrae in reply to helvella]

I am sorry must of worded it wrong. My question is does synthroid lose potency after expiration date listed on bottle?

[helvella Administrator in reply to Mccrae]

I thought I'd answered that!

Yes. Of course it does. But only at pretty much the same rate it has been losing potency from the day it was made. There is no cliff edge where its potency drops faster.

[RedApple Administrator in reply to Mccrae]

We are not qualified to give an official answer to your question specifically about the Synthroid brand.

However, it's very unlikely that the potency will vary much at all for quite some time after the expiry date. I have personally used another brand of levothyroxine for up to a year after expiry, and noticed little to no difference in potency.

[Titaniumfox]

Every medication eventually expires! However it doesn't go from 100% to 0% overnight, just slowly reducing in effectiveness. I would think if it expired 12 days ago you are still good for some months. Also depends on how you keep the product stored.