Thyroid UK
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Is it my imagination?

Hi all

I’m recently diagnosed after visiting my doctors once/ twice a month for 3 years I was finally diagnosed with hypothyroidism 10 weeks ago.

Initial dose of Levothyroxine was 25mg and afte4 a battle with my doctors I have just had an increase to 50mg. It’s only been two days and 8 feel fantastic is it my imagination that the medications made a difference this quickly?

12 Replies

It takes 6 weeks for thyroid hormone to circulate and reach all your cells. Did you change thyroid hormone formulation or brand? It could be the fillers in the tablets making a difference.


Don’t rain on my parade Lol! No I didn’t change brands just increased dose. 25mg made me feel slightly better after an initial few days of feeling really well. Since the increase I feel even better. I know they’re not supposed to kick in for a few weeks but I’m not imagining the way I feel. I wear a fit bit and previously I was bradycardia heart rate was 45-55 heart rate today 70-80. Also not getting the extreme drops in blood pressure.

Can you explain about the fillers?

1 like

Different manufacturers use different excipients to bind the active ingredient into the tablet. Although the active ingredient LT4 is the same in all Levothyroxine, the excipients can vary between brands and sometimes between tablet doses. Check your patient information leaflet to compare excipients. some tablets contain acacia, for example. TEVA tablets contain manitol which is not in other formulations. Some people find formulations are not interchangeable.


But why would the fillers be making me feel better?

No I haven’t changed tablets I’m still using the 25 mg tablets I was taking when I started except I’m taking two so nothing has changed.


If you haven't changed tablets then just be glad you feel better.


Thank your lucky stars. Some people to react amazingly well to Levothyroxine


I think I’ve been incredibly lucky but maybe it depends on what symptoms a person was suffering with and whether levothyroxine acts quickly on that particular symptom. My low heart rate, persistent angina and blood pressure were my most troublesome symptoms.My heart rate is 76 ish as opposed to 45/50 and my blood pressure is normal 120/70 as opposed to 70/40 so huge change for me.

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I totally see what Nanaedake says, as I know using particular Levothyroxine T4 brands/ fillers makes a HUGE difference to a friend of mine (it’s the difference between her being ill or well), but in my own personal experience like you I felt instantly better going up a dose of Levothyroxine T4 - and felt much better even faster once I’d added Liothyronine T3. That really blew my socks off!

Each time the I titrated up a dose with both T4 and T3 the results were really noticeable very quickly - possibly because I’d been under medicated for so long - and I knew when I’d gone over my T3 levels pretty soon too.

I would imagine if we’re fairly in tune with our bodies, or are feeling so goddawful that the only way is up, we might notice an increase in medication more than most... Just my tuppence!

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Thanks for the reply. You have discribed what I experience perfectly. Like you I think I know when my levels are off. When I first started T4 I felt better very quickly but it was short lived. When I had the increase I again instantly felt better but now I’m starting to feel as if the levels are off again because I don’t feel well again albeit not as bad as previously. My heart rate has also dropped again. I’m going to wait until my next blood test is due and get a private test as well. The Lab here will only test the T4 regardless of what the doctor requests. I’ve read the problem could be that I’m not converting T3? If that’s the case I might be able to persuade my doctor to prescribe t3 if the private test shows a problem.


Good luck rosserk!

My GP knows I’m self-prescribing 25mg T3 twice daily, and still won’t give me a prescription so that I don’t have to buy it online from abroad.

He just doesn’t think T3 is a thing as that’s not what the NHS are advising for GPs at the moment. For two years I asked him for extra thyroid help as I knew - because I could feel it - that I was totally undermedicated.

I’d been on Levothyroxine for over 15 years, so I knew the feeling of being without it was the same as being on a too-low dose. I also requested all the right blood tests and finally even asked for T3.

During this time I was sleeping most of the day and I was pretty much housebound. I was so sick!

In the end I bought the blood tests myself AND the T3, and despite the rapid and evident improvement in my health (although I still have huge health problems and consider myself semi-disabled to disabled, my pain has decreased significantly and I can now juggle two jobs!) and the evidence in front of him, my GP - who I get on with and who has been supportive about many other things - will not prescribe me the T3 my body evidently needs because ‘NHS central says no’.

So with my GP’s knowledge (and displeasure!) I’m having to import potentially dodgy medication from abroad, and yet he’s happy handing me Tramadol for the pain like sweeties. It’s absolutely bonkers!

/rant (apologies!)

Anyway, I hope you find something that helps you reach your healthier self, and a medic to support you on your journey. Here’s hoping!

Good luck,



Thanks Abi 😊

I don’t understand the mentality of a Doctor who would refuse to help a patient. Has there ever been a challenge against the NHS by Thyroid organisations?


Yes, as far as I understand it (and a quick google will no doubt confirm or refute this!) Thyroid UK are on it and doing their best. They managed a change to the NICE guidelines this year with regards to T3, but the NHS is still resistant due to cost.

Thyroid UK have also raised media awareness of the sole NHS-approved T3 manufacturer increasing their costs by 6,000% (convenient! Bloody monopoly. Grrr). The company is currently being investigated.

Meanwhile, we’re reliant on the lovely Admins on this Thyroid UK forum, as the vast majority of our GPs and Endocrinologist are leaving us languishing.

But at least we’re in good company with fantastic support from the guys here!


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