Low dose Levothyroxine: Hi everyone! I have been... - Thyroid UK

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Low dose Levothyroxine


Hi everyone!

I have been diagnosed with subclinical hypothyroidism for 6 months and the doctor has now given me 25mcg Levothyroxine to start me off and see if it improves things without affecting my heart (no known issues there). My question is... how quickly will I know if it is working? Also do I have to wait a full hour after taking it before I can have my morning coffee? I'm definitely sub human before my coffee....

20 Replies

Obviously I have no idea of the blood results which led your doctor to this diagnosis. Could you post them? 25 mcg is an extremely small dose.

You do have to wait an hour before your coffee and food, two hours between Levo and other meds, for hours between calcium and iron.

I think how soon you feel any improvement will depend on how low your levels are.

Peglar in reply to Hidden

So TSH was 6.24 and T4 was 15.4.

Hidden in reply to Peglar

That TSH is high and doctor is obviously using it for diagnostic purposes as FT4 is in range.

You really need FT3 result for proper evaluation of bloods - and always post ranges in brackets as they do vary from lab to lab.

Peglar in reply to Hidden

i guess i will have to fork out for another private blood test to get t3

May even feel worse on that dose ,need blood tests after every 6-8 weeks and dose increases until TSH about 1 or below and FT3 and FT4 in upper half of range.Folate,ferritin,B12 and D3 need to be optimal for you as well.

Then some symptoms will go quick others may linger.With me it was around 12 months before most had gone. By which time I was Type 2 diabetic.

Peglar in reply to Treepie

Folate ferritin b12 were all normal and d3 was elevated. I already was supplementing with them

Hidden in reply to Peglar

Treepie is quite right. It will take a time to titrate to your optimal dose and small starting doses tend to make you feel worse.

Treepie in reply to Peglar

Normal just means within range ,not necessarily optimal for you.Seaside Susie is the vitamin expert.

Peglar in reply to Treepie

B12: 123pmol/L

Folate: 22.3pmol/L (so is in range but on the low side)

Ferritin: 306ug/L (so is in range but slightly elevated)

D3: 103nmol/L (so is right at the top of the in range value)

Oh, yes, you absolutely have to wait the full hour before having coffee. 25 mcg is a teeny weeny dose, so you don't want to do anything to compromise absorption.

And, because it's such a small dose, it might not make you feel that much better. Doctors just do not understand that starting on such a small dose can be counterproductive, because it's enough to stop your thyroid producing hormones, but not enough to replace it. So, when you ask how quickly will I know if it is working?, it's a very difficult question to answer.

It all depends on what you mean by 'working'. Levo is not the same as aspirin. Aspirin is a drug and may or may not relieve your pain. If it doesn't, you'll know it's not working. But, levo is not a drug, it's a hormone, and it has a lot of things to do. It will 'work', it will do what it's supposed to do, it's just that you many not feel the benefits for quite a long time. You might be lucky, and feel a bit better after a couple of weeks, but it takes six to eight weeks for the body to fully process the levo. There are no instant results with hormones. And, with it being such a small dose, you might not feel any better until the dose is increased. So, if you don't feel better quickly, don't be disheartened, make sure you get retested after six weeks, and insist that your doctor increases your dose by 25 mcg.

It can take a long time to get back to the old you. Patience is essential. But, be confident that you will, eventually, get to where you want to be. :)

Peglar in reply to greygoose

Thanks! I'm only 38 but had chemo and radiotherapy 20 years ago for hodgkin's lymphoma in my chest which is almost certainly the cause


Standard starter dose of levothyroxine is 50mcg (unless over 65 years old)

The aim of Levothyroxine is to increase the dose up from 50mcg, slowly in 25mcg steps, until TSH is under 2 (many need TSH significantly under one) and most important is that FT4 is in top third of range and FT3 at least half way through range

NHS guidelines on Levothyroxine including that most patients eventually need somewhere between 100mcg and 200mcg Levothyroxine.


Also what foods to avoid (eg recommended to avoid calcium rich foods at least four hours from taking Levo)

It takes 6 weeks for full effect of each dose increase.

Bloods should be retested 6-8 weeks after each dose increase

For full Thyroid evaluation you need TSH, FT4 and FT3 plus both TPO and TG thyroid antibodies tested. Also EXTREMELY important to test vitamin D, folate, ferritin and B12

Low vitamin levels are extremely common, especially if you have autoimmune thyroid disease (Hashimoto's) diagnosed by raised Thyroid antibodies

Ask GP to test vitamin levels and thyroid antibodies

You may need to get full Thyroid testing privately as NHS refuses to test TG antibodies if TPO antibodies are negative

Recommended on here that all thyroid blood tests should ideally be done as early as possible in morning and before eating or drinking anything other than water .

Last dose of Levothyroxine 24 hours prior to blood test. (taking delayed dose immediately after blood draw).

This gives highest TSH, lowest FT4 and most consistent results. (Patient to patient tip, best not mentioned to GP or phlebotomist)

All four vitamins need to be regularly tested and frequently need supplementing to maintain optimal levels

Levothyroxine should always be taken empty stomach and then nothing apart from water for at least an hour after

Many people take Levothyroxine soon after waking, but it may be more effective taken at bedtime


Many people find Levothyroxine brands are not interchangeable.

Once you find a brand that suits you, best to make sure to only get that one at each prescription.

Watch out for brand change when dose is increased or at repeat prescription.

Many patients do NOT get on well with Teva brand of Levothyroxine. Though it is the only one for lactose intolerant patients. Teva is the only brand that makes 75mcg tablet. So if avoiding Teva for 75mcg dose ask for 25mcg to add to 50mcg or just extra 50mcg tablets to cut in half


Teva poll


No other medication or supplements at same as Levothyroxine, leave at least 2 hour gap.

Some like calcium, magnesium, HRT, omeprazole or vitamin D should be four hours away

(Time gap doesn't apply to Vitamin D mouth spray)

Peglar in reply to SlowDragon

Thank you! so i requested TSH FT4 TPO and TG, didn't know to request FT3. TSH and FT4 were as above, TPO came back normal so they as you pointed out refused to do the TG. As an aside i have elevated IgA levels (only marginally) which can lead to all sorts of nasty other things so am monitored annually for that.


If you took your levothyroxine at bed-time, you would not need to wait for your morning coffee!

Have a read here:


Lots of opinions.

I take mine at bed-time, but because I always have done so, I cannot make a comparison.

Timing of levothyroxine administration affects serum thyrotropin concentration.


Effects of evening vs morning thyroxine ingestion on serum thyroid hormone profiles in hypothyroid patients.


[The effect of three kinds of thyroid hormone preparations on serum thyroid hormone and TSH in primary hypothyroidism].

The best time to take thyroid hormone preparations is at bedtime.


Hidden in reply to helvella

It’s a good plan but doesn’t that mean you have to go without food for four hours before bedtime?

Wot? No chocolate?

helvellaAdministrator in reply to Hidden

My meal is (usually) much earlier and I don't worry too, too much about a square or two of chocolate during the evening... :-)

(But you are right to point out the possibility of interference with absorption.)

wellness1 in reply to helvella

"Both of serum T3 and T4 can directly inhibit the secretion of pituitary TSH, but serum T4 is more closely related to TSH than is T3."

This quote is from the abstract of the third article to which you linked. (can't take on the full text atm) Am I missing something? It's commonly said here that any T3-containing hormone replacement, whether liothyronine or NDT is more likely to result in low or suppressed TSH.

Sorry, a bit off topic from the OP.

helvellaAdministrator in reply to wellness1

I wouldn't make too much of it as the paper is quite old, it has been translated from Chinese, and there is not further information as to what was observed.

I can think of many ways of interpreting those words.

Thanks everyone that's plenty to get on reading! I wonder when the medical profession will start listening more to anecdotal evidence... I.e. patient feedback

Marz in reply to Peglar

Follow the money ! Research is expensive and mostly financed by Big Pharma - so as medicine is a business they need a return on their investment ! Prescribing many other drugs for the symptoms of an un-diagnosed or under-treated Thyroid is a goldmine !

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