Does L-tyrosine lower TSH and raise FT4 please? - Thyroid UK

Thyroid UK

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Does L-tyrosine lower TSH and raise FT4 please?


After posting "Muscle Stiffness" on here 3 days ago, 5 people commented that my TSH was too-high normal and my FT4 too-low normal, and may help to explain why my muscles are still stiff despite stopping a short 12 week course of statins in April 17, 2 years ago.

So, I would like to know if L-tyrosine can help lower TSH and raise FT4?

Or Natural Thyroid?

Or potassium iodide?

I eat a vegan diet

Thank you

ALps Holiday

7 Replies


So, I would like to know if L-tyrosine can help raise TSH and lower FT4?

Have you got that the wrong way round?

TSH 3.71 (0.27 - 4.2)

Free T3 4.97 (3.1 - 6.8)

FT4 14.2 (9 - 25)

As you are not on any thyroid medication (where the aim would be to get TSH down to 1 or below with FT4/FT3 in the upper part of their ranges), your current results are classed as euthyroid (normal). However, your TSH is higher than one would expect to see in a normal healthy person - one could expect to see that no higher than 2, with FT4 possibly mid-range. Your FT4 is 32.5% through it's range and your FT3 is 51% through range.

As you also have a Free thyroxine result of 13.400 (12 - 22), what was TSH and FT3 when that was tested?

Were all your tests done early morning, no later than 9am, fasting overnight and drinking water only before the test?

What are your current levels of

Vit D




Or potassium iodide?

It was explained in reply to your previous post why it isn't a good idea to supplement with iodine and that you should test iodine level before considering supplementing with any form of iodine.

gabkad in reply to SeasideSusie

Susie, who tests urinary iodine? I know the spot test is usually only used for research and population studies. I'm in Toronto. Iodine test is not on the Ministry of Health list for

tests covered by government health insurance plan. If I would go to the doctor and ask for it I'd be told 'we don't do it' (along with a myriad of other tests). It needs to be done privately and only a couple of labs do it.

So if this person is in the U.K. who does iodine testing?

It wouldn't be surprising if she is low iodine though. Vegans don't consume

dairy and in the U.K. dairy is the number one dietary source of iodine. Same

as here in Canada. Seems that iodized salt (which is not up front and centre

in U.K. supermarkets) generally doesn't provide enough iodine. Plus

most people especially health conscious ones prefer 'natural' salt (even

though sea salt these days contains microplastics and radiation due to fallout

from nuclear bomb testing.)

Dulse (seaweed) is a decent source of iodine. Not too much like kelp.

..... it's raining again. I know you peeps over there need some. I'd love to share.

SeasideSusieAdministrator in reply to gabkad

It's Genova Diagnostics, I think the samples are forwarded on to the US for testing.

radd in reply to gabkad

UK is good thank you gabkad, so keep your rain. 😃

If you are hypo, you want to raise free t4. If you are hyper, you want what you've asked for. Lemon balm and bugleweed *may* help to raise TSH and lower free T4.

If you are actually hypo, and the reason for low thyroid hormones is protein deficiency or iodine deficiency, L'Tyrosine and iodine would raise free T4. But if the reason is anything else, it won't make any difference long term. If your car has half a tank of petrol, but the battery is flat, topping up the tank won't make it go. Vegans have to be very careful to get enough protein, iron and B12. Nuts, seeds and beans contain tyrosine. You probably need to supplement B12. You also need cholesterol to make hormones.

I am also vegan vegan diet and thyroid means exactly what when worrying about the thyroid ?

I do supplement b12. I test iron and ferritin every year and it is actually amazing and now low.

gabkad in reply to Nora3

Nora3, start a new thread for yourself. Then people can answer your questions.

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