T4 only making me worse: Hi folks. Could someone... - Thyroid UK

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T4 only making me worse

Thyroidfun profile image

Hi folks. Could someone please help me interpret what’s going on here- started Tirosint 25mg 6 weeks ago. Feel and look much worse. Levels checked, my t4 has gone up to 12.8 from 10.8, but my t3 has gone DOWN from 2.4 to 1.3. From what I’ve read on STTM blog I think this means conversion issues and I have t3 meds arriving on Friday to try adding. Wondering if my rt3 might be high because of chronic illness too but that isn’t getting tested. My current endo is a traditionalist and I want to scream at him but I’m winning him over I think...

Update: Guys, I was willing to listen to your advice and my endocrinologist had similar advice. But I failed to mention (I don't know why, I guess I just thought I must be crazy)that last Saturday I took 50mg and actually went to A&E I felt so dissociated, brain fogged, anxious and dehydrated and with INSANE facial oedema. Now, this morning reading your comments I'm second guessing my own sanity and thinking could that have been something else? No. It wasn't. I took 50MG this morning. My face has blown up. Mye eyes are swollen it feels weird to blink. And I feel crazy and extremely anxious and spaced out. Also I'm constipated I haven't gone to the bathroom in 3 days. Even laxatives aren't helping me. This is DEFINITELY the levothyroxine this is not normal, and taking more is not going to help me.

**Not blaming anyone here for me taking the 50mg again. Not your fault that I didn't mention hospital... I was just gaslit by the doctor when I went there and so I blamed myself and didn't trust my own body.

14 Replies
SlowDragon profile image

Too early to add T3

Results show you are under medicated and need dose increase to 50mcg

Starting on too small a dose often makes symptoms worse

Standard starter dose of levothyroxine is 50mcg

Dose is increased slowly upwards in 25mcg steps. Bloods should be retested 6-8 weeks after each dose increase

guidelines on dose levothyroxine by weight

Even if we frequently don’t start on full replacement dose, most people need to increase levothyroxine dose slowly upwards in 25mcg steps (retesting 6-8 weeks after each increase) until eventually on, or near full replacement dose

NICE guidelines on full replacement dose



Consider starting levothyroxine at a dosage of 1.6 micrograms per kilogram of body weight per day (rounded to the nearest 25 micrograms) for adults under 65 with primary hypothyroidism and no history of cardiovascular disease.

Also here



Traditionally we have tended to start patients on a low dose of levothyroxine and titrate it up over a period of months. RCT evidence suggests that for the majority of patients this is not necessary and may waste resources.

For patients aged >60y or with ischaemic heart disease, start levothyroxine at 25–50μg daily and titrate up every 3 to 6 weeks as tolerated.

For ALL other patients start at full replacement dose. For most this will equate to 1.6 μg/kg/day (approximately 100μg for a 60kg woman and 125μg for a 75kg man).

If you are starting treatment for subclinical hypothyroidism, this article advises starting at a dose close to the full treatment dose on the basis that it is difficult to assess symptom response unless a therapeutic dose has been trialled.

BMJ also clear on dose required



Guidelines are just that ....guidelines. Some people need more some less


Extremely important to regularly retest vitamin D, folate, ferritin and B12

SlowDragon profile image

What were your thyroid results BEFORE starting on levothyroxine

Please add vitamin results too

Don’t have my vitamins, but it they are as quoted above (don’t think I was clear on that). Here’s a pic.

SlowDragon profile image
SlowDragonAdministrator in reply to Thyroidfun

Please add ranges on these results (figures in brackets after each result)

shaws profile image
shawsAdministrator in reply to Thyroidfun

It is always necessary to quote the ranges when we state the results. The reason being that labs differ in their machines and so do the ranges. Ranges are needed for members to respond to the results.

Thyroidfun profile image
Thyroidfun in reply to shaws

Sorry, I did but the photo got cropped. Here:

SlowDragon profile image
SlowDragonAdministrator in reply to Thyroidfun

So you need thyroid antibodies tested, vitamin D, folate, ferritin and B12 too

I don’t have antibodies. He didn’t test vits from this test, but he did on the second (ie 6 weeks on Levo) trying to obtain these from him and will send when I have

SlowDragon profile image
SlowDragonAdministrator in reply to Thyroidfun

Have you had BOTH TPO and TG thyroid antibodies tested

If TPO or TG thyroid antibodies are high this is usually due to Hashimoto’s (commonly known in UK as autoimmune thyroid disease).

About 90% of all primary hypothyroidism in Uk is due to Hashimoto’s.

Low vitamin levels are particularly common with Hashimoto’s. Gluten intolerance is often a hidden issue

Link about thyroid blood tests


Link about Hashimoto’s


Also thyroid ultrasound scan done?

20% of Hashimoto's patients never have raised antibodies


Paul Robson on atrophied thyroid - especially if no TPO antibodies


Thank you. I’ve never had antibodies but maybe should ask to test them again. But if you have no antibodies, how do you know if you have Hashi’s? Haven’t had a thyroid scan but it’s been examined manually... I have secondary hypothyroidism though

SlowDragon profile image
SlowDragonAdministrator in reply to Thyroidfun

Secondary hypothyroidism because of ?

Hey Thyroidfun. Please do NOT take the T3. You are on a stupidly low amount of replacement which will be interfering with your normal production whilst not actually replacing with enough. Please first of all replace with the correct amount. Going up in increments of 25mcg every 4-6wks, do a blood test + plus analysis of how you feel till you get to the correct replacement dose.

Usually adults will need at least 75-100mcgs of Levo/Tirosint before feelings effects. Taking too low an amount is as bad, or worse as taking none or too much.

Hello Thyroidfun and welcome to the forum :

There could be a mixture of things contributing to your situation and we do need to see what is going on with more detailed blood tests.

It is true that chronic illness can influence T4 to T3 conversion, as can low vitamins and minerals, inflammation, depression, any physiological stress either physical or emotional, dieting and ageing.

In the first instance it will be a good idea to arrange a full thyroid panel to include inflammation, ferritin, folate, B12 , vitamin D and thyroid antibodies so we have a better idea of where you are in your thyroid journey.

If your doctor is unable to process this request there are private companies listed on the Thyroid uk website, who are the charity who support this forum and where you can start learning of all things thyroid.

Once with these results simply throw up results and ranges in a new post and you will receive considered opinion from forum members.

This is where we all start and just gives us bench numbers to work from to help you become more informed and access better thyroid health treatment.

Synthetic T3 - Liothyronine is much more powerful than T4 - as it is the active hormone that the body runs on and I would not advise anyone to take it until we know your core strength is strong and solid and able to support you through this transition.

It is too soon to be able to tell whether you might benefit from added T3. And it's too soon to be able to tell how good or bad your own conversion of T4 to T3 is.

The extremely low starting dose of 25mcg is an explanation for why you feel worse..... it's enough to mess with your own feedback/control system (which affects how much of your own T4/3 you make and how efficiently you convert T4 to T3 ).. but not enough to properly replace you need for thyroid hormones.

You would do better to increase dose of levothyroxine (synthetic T4) until fT4 is in top third of lab range, and TSH is around 1 (or possibly below 1)...only then can you compare your fT4 and fT3 results on that dose to see how much T3 you will be able to get from Levothyroxine.

If you add T3 before you've tried a full replacement dose of T4 only, it will lower your TSH much more than a full dose of T4 would, and this will lead to problems with getting enough T4 prescribed.. it will also prevent you from ever finding out if you could be one of the majority of people who do well on Levo (T4) alone (and have good enough natural conversion to make enough of their own T3)... and if you can be well on T4 alone it is much simpler and cheaper to manage (for life) than adding/sourcing T3 (and having constant arguments with Doctors every time they see your TSH is low and insisting you are overmedicated and must reduce your total hormone dose because they don't understand how to monitor dose in patients on T3, and are taught (incorrectly)that a low TSH always has risks of heart and bone problems.

rT3 is a bit of a red herring (STTM haven't updated their information to include more recent research)....... there are many causes for rT3. it's a perfectly natural safety valve for excess T4 control , but it is also raised by many many other situations, so if it's raised you still don't know why (unless fT4 is way over range, in which case that would be an obvious explanation, and you could tell that from looking at fT4 result.. so still no real need to do an expensive rT3 test.

This post contains a link to an explanation of why STTM are out of date on this issue, and the site it links to ..Thyroidpatients.Ca is much more trustworthy for understanding the current science than STTM is ...... healthunlocked.com/thyroidu...

Here is a list of all topics they cover ... thyroidpatients.ca/home/sit...

STTM are still writing form an old idea that rT3 'blocks' T3 receptors.

however, ...reverseT3 does not 'block' the receptors inside the cells that T3 uses. it simply can't chemically 'fit ' onto them. It fit's on to other receptors on the outside of the cell wall.

The clue is in the name .. it's 'reverse', ie. the molecules of iodine are the opposite way round to T3.. which is why they can't fit into the same receptors that T3 does.

For this reason their 'pooling ' theory is also out of date.

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