how long does it take for t4 to come down after reducing dose?

[Goinginsane1]

Over the last couple of weeks or so I have been ever so slightly increasing my dose as my TSH was going over (under active) and having low stomach acid and achey muscles etc. however my t4 was already too high and this has made it go even higher and I have felt really poorly as it has and is affecting my heart.

I have lowered my dose back down to what I was taking before for the last 4/5 days but I am still having problems with my heart especially late afternoon which seems to be when the symptoms peak.

my heart isn’t working as it should it feels weak and having chest pain but trying to tell myself that it wil pass once the t4 comes down abit.

How long will it take for the t4 to come down? I was hoping after 4/5 days I would feel a little better but if anything my heart feels worse 😞

I only increased dose slightly for about 2 weeks or so.

[TiggerMe Ambassador]

7 day half life for T4 so you are nearly there if you have also reduced or stopped you dose🤗

Increasing when your fT4 is already over the top isn't a great idea, hypo's don't always make the best decisions 😕... if your TSH is still too high it is in response to the fact you aren't converting enough to fT3 and what you need to be doing is adding T3

TSH 2.58 mIU/L (0.27 - 4.2) 58.8%

Free T4 (fT4) 26.1 pmol/L (12 - 22) 141.0%

Free T3 (fT3) 4.5 pmol/L (3.1 - 6.8) 37.8%

T4:T3 Ratio 5.800 

How sensitive are you to changes in T4 as it could be worth stopping for a couple of days and the drop your dose down

[Goinginsane1 in reply to TiggerMe]

yeah I’ve learnt the hard way.

When I start eating more (which I need to do as I haven’t been eating enough for a long time) to the amount I should be eating my tsh goes up and over 4 and I get low stomach acid and horrendous fatigue and achey muscles like the worst flu.

I knew my t4 was already high and last time it happened last November when I started eating more then I didn’t increase the meds and the only way to bring my TSH back down was to eat a bit less again. This time I thought that I need to eat more regardless as I’m under 8st now and underweight and need to eat and I would just have to increase levo so I can carry on eating but sure enough my t4 has gone up and caused me some awful over active symptoms most worryingly affecting my heart and it’s definitely not working properly. Couldn’t sleep at one point, diarrhea at one point, and even more anxiety.

I only increased dose marginally (12.5 ish) but that’s all it takes. I am so sensitive.

It’s so hard to try and find a balance of the under and over active symptoms and the right dose.

I guess I just have to ride out the next few days and pray my heart goes back to normal. I am waking in the night/early morning and it feels like it’s stopping almost and waking me up. This could be my anxiety though 💁 my heart definitely isn’t working properly though and it is down to the thyroid and t4 levels I am sure of it.

I lowered dose back down to slightly less than 75 which is what I took before for months but eating around 1600/1700 calories and seemed to manage the tsh and t4 to just about in range then so maybe I will have to go back to that and hope I put a little bit of weight back on as the t4 won’t be so high and increasing my metabolism 💁

I am on day 5 of back to original dose today but my heart and chest feels worse yesterday, last night and this morning 😞

I’m not sure what the half life means? Does it mean that it takes about 7 days to start coming down?

[TiggerMe Ambassador in reply to Goinginsane1]

Half life means how long something stays active in your system, you really don't want your fT4 above 80% 24 hours after last dose as this can lead to lower conversion

Your heart would really benefit from T3, have you asked for a referral to Endo?

[Goinginsane1 in reply to TiggerMe]

I had an nhs endo appointment about 5 weeks ago and it was a total waste of time. I showed him the medichecks results and tried to explain what is happening and when and showed him the t3 and t4 results and graphs and he just said they were fine! 😞 and the t3 is as normal. It was absolutely shocking.

Does that mean that I won’t start to feel any better for at least 7 days after rescuing dose back down? Do I just need to ride out the next couple of days and hope my heart starts to go back to normal. I’ve even thought about going to a&e but not sure they can do anything as I just need to wait for the thyroxine to leave my system don’t I?

I took propranolol last year and it caused my severe chest pain and I though my I was having heart attack when I stopped it that pain went so reluctant to take that for my heart problems I’m having now. I’ve got diazepam to calm me down in emergencies but I am reluctant to take that too

[TiggerMe Ambassador in reply to Goinginsane1]

I wouldn't recommend bombarding your system with anything else if you can just let it sort itself out.... hopeless Endo 🙄 I'd get on and buy your own T3, probably worth have a conversation with Roseway?

[Goinginsane1 in reply to TiggerMe]

Who is Roseway?

[TiggerMe Ambassador in reply to Goinginsane1]

It is a company that many here deal with for T3... rosewaylabs.com/patients/

[DippyDame in reply to Goinginsane1]

To be clear...

Yes, you are correct to say levo will start to come down after 7 days but...it's an exponential reduction.

The half-life of a drug is the time it takes for the amount of a drug's active substance in your body to reduce by half. This depends on how the body processes and gets rid of the drug. It can vary from a few hours to a few days, or sometimes weeks.

Once the active substance (levo) is reduced by a half life, the remainder will then be reduced to half after a further 7 daysand this will continue until however many half lifes elapse...or it is eliminated

So...the half life of levo is approx 7 days so after taking a dose of say 50mcg, there will be 25mcg active substance ( levo) left after 7 days. After the next 7 days 12.5mcg will remain...ond so on.

So 50 mcg would need 28 days to reduce to 3.125mcg.....and so on to zero.

Higher does than this example (50mcg) will take relatively longer to be eliminated

[Goinginsane1 in reply to TiggerMe]

these were my results a week before I increased dose a few weeks ago but was having under active symptoms and tsh was about to go over as I started eating more…

.

[TiggerMe Ambassador in reply to Goinginsane1]

I'm not sure about the connection between calorie intake and TSH?

These results show that you need to reduce your T4 slightly and need to add T3 due to poor conversion, adding more T4 won't help

[Goinginsane1 in reply to TiggerMe]

and these were my results in December before I started eating more on slightly less than 75

.

[TiggerMe Ambassador in reply to Goinginsane1]

These too show that you need T3 even though your conversion was slightly better with lower fT4

[DippyDame]

Don't worry about TSH, once replacement hormone is taken TSH is no longer a reliable marker, science proves this.

The most important readings are FT3 followed by FT4

Overdosing on T4 will cause the side effects you mention

While it is important to reduce your T4 dose that is only part of the issue. Your FT3 is low most likely due to poor T4 to T3 conversion

The low FT3 is the thing you now need to address.

For good health every cell/ T3 receptor in the body must be flooded with T3 by way of an adequate and constant supply.....low FT3 = poor health.

Your T3 supply is far too low!

The heart needs a great deal of T3, your heart symptoms need more available T3 to resolve them.

Have you optimised vit D, vit B12, folate and ferritin? All essential to support thyroid function.

Over range FT4 is to be avoided in the long term since it can cause other issues, not least an increased risk of cancer.

You won't have done any harm by the brief levo increase but consulting an endo with a view to having T3 prescribed should be your next step

Once you raise your FT3 to roughly approaching 75% through the ref range your symptoms of undermedication should resolve

It won't be a quick fix because the T3 must be added low and slow....but there is a fix!

We have to be very patient....that, I found very difficult, but it proved to be essential

It can all seem a bit scary but once you better understand what the problem is and how to fix it things should be less stressful...been there!

Do not let them dose you based on TSH! FT3 followed by FT4 are the important lab results!

Speak to your GP and request an appointment with an endocrinologist who hopefully will understand your need for T3.

We're all here to help...just ask.

Good luck

[SlowDragon Administrator]

You will initially feel hypo reducing dose but you need to stick with it

Retest after 6-8 weeks

Meanwhile get vitamins OPTIMAL

THEN can look at adding SMALL dose T3

Initially 5mcg or 2 x 2.5mcg per day

Do you always get same brand of levothyroxine at each prescription

[Goinginsane1 in reply to SlowDragon]

I am so unwell. My heart feel shallow and having chest pain and feel sick. I’m so tired. My heart seems to have got worse since I lowered my dose back down 5 days ago. Not sure if it’s due to that or if it is still due to high t4.

It’s brought on my period after 11 days too which is obviously affecting hormones and that won’t be helping my severe anxiety either. I suspect the high t4 has caused that too. I have made myself even worse than I was before by increasing dose but I felt like I had to due to the TSH going over when I start eating more and I was struggling to eat with low stomach acid in an attempt to carry on eating more.

I have lowered my dose and now having to watch what I am eating but that is not enough and my body needs more food.

My heart feels really weak and is getting worse since lowering my dose back down but not sure if it’s coz of still high t4 or due to even lower hormones as it’s brought my period on after 11 days too.

I’ve taken a diazepam 2 hours ago but is hasn’t helped 😞

Tempted to try propranolol but maybe half a tablet but I know that is caused severe chest pain and burning up into my shoulder and ear like it was a heart attack or something so scared it will do the same again.

[SlowDragon Administrator in reply to Goinginsane1]

What dose propranolol tablets have you got

I took 4 x 10mg propranolol per day for almost 20 years …more on my profile

It did help with the massive anxiety of being hypo (low Ft3)

Was able to SLOWLY get off it once Ft3 started to improve

[arTistapple]

I think even 12.5 mcg is not all that ‘slight’ when possibly near the top of the range (or indeed if you are lucky enough to be near a sweet spot).

I am trying 6.25 mcg at the moment because a year ago a t..t of an endo increased it by 25 mcg in one go, with awful results. Well over range, plus symptoms. Like you, I am nervous of heart and anxiety symptoms.

I will miss out days if I think even this is too much. Plenty of references here on the forum of people taking different dosages alternate days to try and balance what is happening. After no success as yet with T3 and kept having to withdraw it, I am trying to squeeze a bit more out of levo. Weight wise I am nowhere near the recommended dose but get very unpleasant symptoms if I take too much.