How do we absorb thyroid medication?

[Dee1]

This is probably something I should know - but how do our bodies utilise thyroid medication? Does our digestive system affect this? If we don't have good digestion or don't have a healthy microbiome, does this affect absorption? Similarly if our liver isn't working as efficiently as it should, does this affect things? Many thanks. Any information on what affects absorption and efficacy of thyroid medication gratefully received. I understand about what foods etc to avoid having near medication time, but don't really understand the physiological processes that enable the meds to work .

[shaws Administrator]

If we take levothyroxine (T4 only) is an inactive hormone and it has to convert to T3 (liothyronine) and it is T3 which is the Active Thyroid hormone needed in our millions of T3 receptor cells and brain and heart contain the most.

Food can affect the uptake of the hormones, and that's why it is recommended to take on an empty stomach and that is usually when we awake and take it with one glass of water and wait an hour before eating.

Some people prefer a 'middle of the night dose' when they awake to go to the toilet.

The following link is items by one of the Researchers and the Team which you will find informative.

healthunlocked.com/thyroidu...

[SlowDragon Administrator]

Here’s a pretty in-depth research article

academic.oup.com/edrv/artic...

Gastrointestinal malabsorption of oral T4 represents an emerging cause of refractory hypothyroidism and may be more frequent than previously reputed.

[salmanc1 in reply to SlowDragon]

Which leads me to why there isn’t a way to take t4 via a skin patch or slow release mechanism without the gut ? Would be interesting to see if a Pharma company decides to try that.

[helvella Administrator Thyroid UK in reply to salmanc1]

Because thyroid hormone does not readily transport across skin!

It is possible that with some "help" from other compounds, a mechanism might eventually be identified. Even then, it might not be satisfactory. For a start, the skin it is stuck onto would likely be effectively severely over-dosed. And we do not currently know whether any thyroid hormone that was absorbed by the skin would satisfactorily get distributed round the body.

Further, I am personally not convinced that the precise dosing needed for thyroid hormones could be reached by any form of patch. Note that a reduction in potency from 90 to 87% has been enough to initiate an FDA/company recall of RLC's desiccated thyroid. Can patches deliver a dose that accurately?

I agree a non-gut delivery method might be a really major advance. I just don't see that being a patch.

[SlowDragon Administrator in reply to salmanc1]

They are working on T3 by hormone capsule under skin

Was post about it a few days ago.....only very early stage of development

[Zazbag in reply to SlowDragon]

This would be amazing!! Please can you share a link to this?

[SlowDragon Administrator in reply to Zazbag]

Here it is

healthunlocked.com/thyroidu...

[Zazbag in reply to SlowDragon]

Thank you!

[helvella Administrator Thyroid UK in reply to SlowDragon]

The idea sounds great.

But...

Do we want to have plastic embedded in our arms (or whatever)?

Is it possible to remove it in a hurry? We see a lot of members discussing Hashi's flares. You wouldn't want an implant adding liothyronine alongside your own thyroid pushing out an excess.

What happens when you need a new one implanted? Do you have to get the timing spot on?

I have long thought that a miniature implantable doing device would make sense. One that can be controlled and refilled from outside the body (e.g. some fancy magnetic/electrical device and a syringe). Easy to turn off, if desired. Easy to adjust dosing regime.

[Lora7again in reply to helvella]

I agree ... what about the women who had the contraceptive Implanon which is a plastic tube inserted in their arms. There have been a lot of women who have had problems with it and think my thyroid problems may have been caused by the Mirena coil another plastic device that is put inside you and releases a drug into your system.

[helvella Administrator Thyroid UK in reply to Lora7again]

They use the same basic polymer - EVA. (Might be a different precise formulation.)

[SlowDragon Administrator in reply to helvella]

I don’t think it’s a good idea....everyone needs such fine adjustments on dose of T3

It would be impossible to decide on a constant dose for 3 months ....we need to start low and increase slowly upwards at a pace and increase that’s highly individual

[helvella Administrator Thyroid UK]

In people without thyroid issues, some thyroid hormone is sulphated and excreted into the gut. This can then be re-absorbed further down.

(Sulphation is simply the addition of a sulphate ion to the T4 or T3. This forms, for example T3-Sulphate - T3-S.)

When re-absorbed, the sulphate can be removed and we are back to having just T3.

Some work has been done on actually dosing with T3-S. The idea being that it has little activity and is, therefore, relatively harmless in that form.

The research initially appeared quite promising but I do not know what has happened more recently.

[Dee1]

Thanks so much everyone for your really helpful responses. I much appreciate them.