Purpose of T4?

[Duckydoodle]

I’ve grown increasingly frustrated with Armour and considering either lowering the dose and adding some Synthroid - or stopping the Armour and trying just Synthroid. I’ve been googling myself to death trying to get an answer to this question or issue: does T4 have any value in and of itself, or is it’s only purpose (which is what I’ve always believed) to be converted to the more active T3? Thanks 😊

[Jazzw]

I see that last time you posted you were advised that you probably needed a dose increase—so what happened next? Did you raise your dose? What dosage are you on now? Do you have recent blood tests to share?

Your body’s been used to having the T3 in Armour, so it may find it a bit of a shock to the system to not have it quite so readily available if you switched to Levo . But at least some of the T4 in your Armour will have been converted to T3.

It’s hard to know how you’d fare. Do you think your doctor might be amenable to referring you to an Endo to get T3 prescribed?

[Duckydoodle in reply to Jazzw]

Hi Jazzw, I have tried slowly increasing my dose of Armour - it’s not been going well. Heartburn and anxiety and higher BP. I feel like since menopause and/or the latest reformulation of Armour it just doesn’t work as well and I don’t know what to think anymore. Aside from fatigue, I seem to feel better on a lower dose. No new labs of late. I’m sure my doc would send me to an endo - I’ve just never met one that seemed to know much about thyroid issues. I’m genuinely curious to know if adding some T4 might help since it seems higher doses of T3 seem to not agree with me, hence my question about the role of T4. Anywho - thanks for the reply. 😊

[Batty1 in reply to Duckydoodle]

I actually met a person last year who took Synthyroid and Armour Thyroid together and had good results. I was on Armour but when I asked my useless Endo at that time she refused to add Synthyroid said "that's not appropriate thyroid treatment" and questioning too much resulted in her using the clam effect and ushering me out the door faster than normal. I bet it has more to do with money vs. anything else although the Endo might say its harder to monitor or adjust "sigh".

[greygoose in reply to Batty1]

I think it has more to do with ignorance than anything else. She clammed up because she didn't have any answers to give you. And she got rid of you before you could ask any more questions she didn't have the answers to. They don't like showing their ignorance.

[Nico101 in reply to Duckydoodle]

That's sort of the situation I'm in. I was told on here there is no reason why you can't take levo and NDTs together and that many people do, so I started on 25mg of levo about 8 weeks ago. I feel a bit better, but have just started to increase the levo to 37.5 to see if a little more will help me reach my sweet spot.

Don't see why you can't try it, too.

[helvella Administrator]

Even if the only purpose of T4 is, in the end, to be converted to T3, it is a bit more complicated.

For example, hair follicles can take T4 from the bloodstream and convert it locally to T3. Much of the T3 in the brains of people without thyroid issues is positively transported through the blood-brain barrier in the form of T4 and converted within the brain.

I've ended up thinking of T4 as doing several things:

Acting as a reservoir of thyroid hormone;

Allowing thyroid hormone to be carried round the body in a form which is safe;

Getting thyroid hormone to tissue which, if it were in the form of T3, would never get there - something else would grab it first.

There is still uncertainty as to what, if anything, T4 itself can do without being converted to T3.

A final thought, around one third of T4 gets excreted, one third converted to T3 and one third converted to rT3. Both T3 and rT3 convert to T2. If you took T3-only in the same dose as your body would have made, then your T2 levels would likely be lower.

[Duckydoodle in reply to helvella]

That’s really interesting to know - thanks so much for replying - I can’t seem to find anything online that speaks to the role of T4 in and of itself, so this is quite a bit of food for thought!

[Nico101 in reply to helvella]

That's a really good explanation. Thanks. My T4 is considered in range, though low, but my hair is still rubbish and my eyebrows and eyelashes aren't growing - yet I feel a bit better in other respects.

I've just increased my levo dose, so it's good to know low T4 may be the issue.

[helvella Administrator in reply to Nico101]

I just hope some of it is true!

I think we all end up piecing together fragments and desperately trying to make sense of them. Right at the beginning of my thyroid journey I remember trying to get my head round how things work and where problems could occur. Yet the standard medicial establishment view is so incredibly blinkered and simply ignores everything beyond a tiny little bit that is trotted out ad nauseam.

For goodness sake, have we not read that "The thyroid is a butterfly shaped gland..." a million times? That all anyone ever needs is levothyroxine? That if TSH is in range, all is well?

If anyone reads my little description above and thinks it is wrong, bonkers, misleading, or just has a typo somewhere, let me know. Let us ascend above what is thrown at us and be as right as we are able.

[jgelliss]

Not everyone needs T3/NDT . Some do well on T4 only or some low dose T3 /NDT with the T4 . Personally I do *Not* do well with much T3/NDT . I feel much better with T4 with a very low dose T3/NDT added. I'm not a good converter T4 to T3 and get palpitations if I don't dose with a tiny dose of either T3 or NDT. The heart has T3 receptor sights.

Nutrients are very vital especially when on thyroid meds . Vitamin "D"/K2 , B-Complex , B-12/folate , magnesium, vitamin "C", Zinc, Celtic Sea Salt.

Best Wishes.

[Duckydoodle in reply to jgelliss]

Thanks so much for the info and reply. I take all of the supplements you mention except for Celtic sea salt. Oddly though I think I used it a few summers ago and lost some weight, coincidence or not I have no idea. Can I ask what you find beneficial about it? Thanks 😊

[jgelliss in reply to Duckydoodle]

Celtic Sea Salt I find helps with adrenal/Cortisol and Electrolytes. I find that T4 can be like diuretic . If you wake up with dry mouth in the morning it can be from T4 your taking.

[Duckydoodle in reply to jgelliss]

Interesting....thank you

[saritadelmar in reply to jgelliss]

Very interesting. I was wondering why with just 5 mcgs of T3 added to my 75 Levo, pretty much stopped my palpitations. With so many on this forum taking larger doses of T3, I was wondering if 5mcgs was too little. Do you mind sharing the doses of Levo and T3 that you take? Thanks for posting this.

[helvella Administrator in reply to saritadelmar]

It is so very tempting to look at what others take. But we always get back to the same thing, you need what you need. Neither more, nor less.

Interest and getting some idea of the possible ranges of doses are reasons to ask. But we are all individuals with our own requirements. Just because someone else takes more should not be taken as meaning that you need more.

[saritadelmar in reply to helvella]

Thank you for your useful comment. I agree with it completely. And I was interested in jgelliss' dosage because she/he is the first that I have read here mentioning a very low dose of T3 doing so much to improve their health and feelings as it has done for me. Her answer to me is surprising, in that she could not take as much as 5mcgs, but had to take less. I thought 5mcgs was the lowest dose, however, I suppose one could split that. Anyway, I am more confident in my dosage now after reading these posts and answers to my question. Thank you again!

[jgelliss in reply to saritadelmar]

Helvella *Is Spot On* . We are all individual and as such our needs are all so different too. 5mcg was too much for me but that does not mean that for you it's not perfect . It's all how you feel emotionally and physically . In addition I had TT so I have no thyroids at all and I'm totally thyroid meds dependent . I know that some on this great community can not have any T4 because it makes them sick . So they dose with T3 only and feel great with it. I tried several different T3/NDT doses over several years and I have come to the conclusion that my body needs more T4 to my lower T3/NDT dose to make me feel more my *Optimal*. I would very highly suggest that you make very small changes with your thyroid dosages and journal your symptoms with changes that you make with your doses. Give it enough time for your body to acclimate to any new changes . I usually notice changes positive/negative within a week when I tweak my thyroid meds.

Best Wishes .

[saritadelmar in reply to jgelliss]

Thank you for your detailed response. I do take it slow and although I feel good with my dose, I was thinking to increase a tiny bit. Your posts have been very helpful. Questions are no longer in the back of my mind and that feels good.

[jgelliss in reply to saritadelmar]

I'm very Grateful if I was able to ease your concerns somewhat . Just know your not alone . We all started out just like you . If you feel well with 5mcg T3 with your T4 I would not want to change . You might over shoot your *Sweet Spot*. Stay on the dose for 6-8 weeks and see how it feels then for you . You might want to run labs with your FT3 FT4 TSH Vitamin "D" , B-12/folate, Iron/ferritin.

Best Wishes .

[saritadelmar in reply to jgelliss]

Thank you again. Will take your good advice!

[SlowDragon Administrator]

As you have Hashimoto’s it’s extremely important to retest vitamin D, folate, ferritin and B12 at least annually

Are you on strictly gluten free diet? Or tried it?

You may be better on levothyroxine plus small doses of T3 alongside levothyroxine

[Duckydoodle in reply to SlowDragon]

The only thing I haven’t had tested recently is ferritin. I do eat a mainly gluten free diet. I feel like I tolerated T3 better when I ate more gluten or carbs. Always something to tinker with....

[TSH110]

You may find the blog posts by Dr Tania Smith helpful, eg:

thyroidpatients.ca/2019/05/...

thyroidpatients.ca/2019/11/...

[SilverAvocado]

Duckydoodle, Everyone is different in the thyroid dose they need. Most people seem to feel well with at least some T3 in their dose or even all T3. But there are also people who need plenty of T4 or maybe even all T4.

It isn't really as important what the specific mechanisms are, as to use trial and error to slowly figure out your own needs.

One thing you could try if you suspect you need more T4 is to start slowly swapping out your NDT in exchange for T4. Do it at the same pace as any other dose adjustment, every 6 weeks, and monitor symptoms, pulse, temperature, etc. If you start feeling an improvement then this suggests it is better for you than NDT only.

[jgelliss]

Great Question and I pondered over it how the T4 affects me personally . From my own personal experiences my brain works better with T4 than with T3. With a higher dose of T3 I feel lethargic fatigued muscle weakness to the point of having difficulty to climb stairs and have weight issues and feel estrogen dominant. So from this I gather and feel that besides T4 converting toT3 which is the more active thyroid hormone we have receptor sights for T4 too. With T4 my sleep is better too. This is from my own experiences being my own *Lab Rate*. Since I'm also not a good converter T4 to T3 I get palpitations and the small dose T3/NDT helps my palpitation to calm down . The heart has receptor sights for T3 as does many other parts of our body.

I'm sure there are others that have totally different experiences that do much better with higher doses of T3 or do even better with T3 *Only*. It's not *One Size Fits All*. We must respect our individual needs to feel our *Optimal*.

[Duckydoodle in reply to jgelliss]

I can relate to much of this....I think it’s time to start adding a micro dose of T4 and see how it goes. Since I decreased my Armour my sleep has been horrible so maybe it will improve a bit. Thanks!

[jgelliss]

If you felt over all better with Armour and your sleep was much better why do you feel that lowering your Armour will be better?

[Duckydoodle in reply to jgelliss]

It’s hard to give a full explanation - I’ve been in Armour at various doses for over 25 years. Since going through menopause and the last few reformulations (basically the last 5+ years) I have not felt my best on Armour at any dose. If I take what used to be my normal (higher dose) I have anxiety, flushing, weight gain, heartburn and feel agitated. So aside from better sleep I don’t think Armour is working as well for me anymore. My functional med doctor was the one that suggested trying some T4 and decreasing the Armour - I’ve been resistant as I’ve always assumed that NDT is better all of the time for everyone period. And I’m starting to question that. 🧐

[jgelliss in reply to Duckydoodle]

Your going to have to experiment and see what feels right for you . You might even try down the line and see if synthetic T3 can work for you too with a small dose of T4.

[jgelliss in reply to Duckydoodle]

It's very possible too that Armour was reformulated a few years ago and it's possible the new form of Armour is not working for you as well as it did when you first started with it . Just something to think about . Unfortunately the few NDT's that are available have been reformulated and many are not happy with the reformulations . They feel hypo symptoms returning and labs prove it .

[Duckydoodle in reply to jgelliss]

Yes, there’s no doubt in my mind that the reformulations have not been for the better. Armour was great when it smelled horrible - now (and for several years now actually) it’s had no odor at all. Unfortunately and as you say, my research of other brands of NDT seem to echo the same complaint. 🙃