How fast can expired Thyroid-S deteriorate?

[Butterfly801]

I just spoke to someone who ordered discounted expired Thyroid-S from a seller. He told her that, since it expired in October 2023, it would have lost no more than +/-1% of its potency as per FDA guidelines.

She started on it in January 2025 (after previously being on a more recent batch that had not expired) and started feeling weird pretty soon. After six weeks on it, her TSH had gone from suppressed to 7, her FT4 dropped below range and FT3 gone from 80% through range after 12 hours to 45%.

Could NDT become so weak a little over a year after expiry, or is this batch paticularly bad (TA 20091)?

I know there is an overview of various batches of Thyroid-S, but cannot find it.

[Carew]

why on earth trust random seller?

fda do not publish loss of potency after expiry date because no-one needs to know.

[Butterfly801 in reply to Carew]

Who says he was random? This is someone she had ordered from for years. Then he only had expired batches and offered her a 30% discount.

[Framboise]

Most brands of NDT are supposedly fine for a while after their expiry date, but a year on is rather a long time when you don't know how they've been stored. I haven't heard of the FDA guidelines on the permitted degradation percentages of medications or hormones which you mention, and doubt any FDA guidelines are used in Thailand anyway. I believe that some expired drugs and medications are sent to certain countries in Africa for their use, but again, I doubt they would be a year out of date when they are sent.

From your friend's blood test results alone it 's obvious something has gone wrong. Helvella's Thyroid-S chart is here helvella.blogspot.com/p/thy... but there aren't any really bad comments about that batch, what is noted is:

"TA20091

Manufactured on 15/10/20, expiry 15/10/23.

One person reported two packs had distinctly different colours - greenish vs brownish."

I hope your friend has now stopped taking that batch and is taking something more recent. I also wonder why the supplier had such old stock but no new stock. That to me would be a red flag I'm afraid.

[Butterfly801 in reply to Framboise]

Thanks for your feedback! The seller said he buys a huge stock every three years or so and does not order more until that stock is gone. He is in Europe which is why my friend orders from him (she is in France so afraid to order from Thailand due to customs). She has found a supplier in Thailand who can repack as vitamins. 🤞

[TSH110]

I have a really old batch (over two years out of date) but it still seems to be fine. I keep it in the fridge in the original bottle and box but am very careful to avoid getting any moisture in it. I have got an in date batch but there is no discernible difference between the efficacy of them and the duff date ones.

So in my experience, if kept cool and dry deterioration over time appears to be minimal.

I hasten to add, I’m not recommending buying out of date ThyroidS and never have done myself, mine was in date when I got it but I got rather too much when supply had got a bit dodgy and panic mode set in.

Any weird blood test results and feeling under medicated are a bad sign.

[Butterfly801]

Yes, the problem is you have no idea how the bottles have been stored. I have read about some batches being very weak/inconsistent and wondered if she might have had a one of these. It seems from Helvella’s document that a few batches were really bad (especially in 2022). As for the colour being different from batch to batch or even from bottle to bottle, I wonder if that has to do with fillers or if it can be a sign of a problem with the pills themselves?