When should I take T3?: So after a definite "no... - Thyroid UK

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When should I take T3?

ceedee81 profile image

So after a definite "no" from the doctor about prescribing me T3, I have ordered some 25mcg tablets myself. My plan is to quarter them to start off with and retest levels in 2 months. Then if necessary, up the dose to half a tablet etc.

I currently take supplements (B complex, vit D, probiotic, omega 3 and turmeric) in the morning. Early evening (about 5pm) I take iron, vitamin C and more vit B as the dosage is 1-4 tabkets a day. I then take my 150mcg levo before bed so it's not taken with any supplements or close to when I've eaten.

I'm also generally having 4 brazil nuts in the afternoon for selenium.

My question is, what time of day should I take T3? I know it only lasts around 8 hours so am I right in thinking that taking it at night won't really help?

18 Replies
SeasideSusie profile image


Some people take their T3 at night as it helps them sleep better. Some people split their dose (which you wouldn't need to do with just 1/4 of a tablet). I take mine all in one go (25mcg).

With your current supplements, I would move your D3 to lunchtime or evening - it should be taken with dietary fat (fattiest meal of the day) and 4 hours away from thyroid meds.

What B vitamins are you taking? As they can be stimulating they are generally best taken no later than lunchtime.

You should take iron on it's own with Vit C, no other supplements as it affects their absorption.

Unless your brazil nuts say on the packaging "grown in selenium rich soil", you can't guarantee that there is any selenium in them. Selenium content in soil varies greatly as well, so even if grown in selenium rich soil, there's no knowing if it's from a selenium rich area or a selenium poor area unless they state where they've been grown.

I take my T3 before I get up in the morning. I generally wake up somewhere around 7 am, take my T3, then snooze for an hour or so. I then get up, get myself ready and by the time I've fed cat and dog and am ready for my breakfast it can be between 1.5 and 2 hours since taking my T3.

I have never felt anything from taking it in split doses, one dose, etc. I've not felt it "not last". We're all different so have to experiment.

I thought all Brazil nuts were from ancient jungles and not for eg from estates, and that selenium depleted soils related more to areas of intensive / extensive areas of agriculture that had been stripped of natural minerals etc like US mass agricultural areas. Who sells Brazil nuts from ' selenium rich soils', anybody actually tested the difference between 'bog standard' supermarket nuts and these, no doubt much more expensive?

SeasideSusie profile image
SeasideSusieAdministrator in reply to Judithdalston

Apparently, from a member's post on here as I don't go there myself, Sainsburys do one with "Grown in selenium rich soil" on the packaging, and Eastern Amazon has a higher selenium content in shelled nuts than Western Amazon.

Oh...a little known fact!

Out of interest I did some research on Sainsbury's various own brand Brazil nuts sold via their online site....all are from Bolivia which according to the Honeyguide site are amongst the producers of the very lowest of selenium content nuts. Their two ordinary ranges ( probably differentiated by one being found with the nuts , the other in the baking sector) were recorded as having 525 ug of selenium per 30 g serving, cost from £1.15 plus per 100 g. The SO organic range were said to be only 75 ug/ 30 g serving at £2.50 per 100g. There was no mention of 'grown in selenium rich soil' on their products, nor did they seem to sell any other brand.

helvella profile image
helvellaAdministrator in reply to Judithdalston

Trouble with a lot of food labelling is that nutritional claims are very often based on typical numbers - not the specific product. Sainsbury might be going further than that and giving us the real values but probably, even then, only what the tested batch contained.

Be interesting to ask them.

Yes, I can believe that. But it's very confusing that a 'fresh' unprocessed product should have 5+ times difference in selenium- one would expect having specifically mentioning selenium content that as customers we were being reasonably informed it was correct say by 10% either way. Wonder if Sainsbury's will give me an answer!

helvella profile image
helvellaAdministrator in reply to Judithdalston

I agree - and it deserves an answer from Sainsbury.

does D3 hinder T3 absorption or why should you take them apart fro each other ?

SeasideSusie profile image
SeasideSusieAdministrator in reply to Philipp_Winsel

Thyroid meds should be taken at least 2 hours away from *any* supplements and other medication, with water only and water one hour each side. This ensures no absorption problems with Levo.

There are some supplements and medications that require longer gaps. I don't have a list of medications but for supplements then 4 hours gap is required for iron, calcium, magnesium and Vit D.

T3 doesn't 'only last about 8 hours'. I stays in the blood for about one day, but the T3 that's absorbed into the cells stays there for three or four days. :)

When I effectively asked the same question recently I got different answers ranging from : take it all in one go ( generally early - an hour or so before breakfast, bedtime or middle of night) or people had split the dose up 2 or even 3 times over the 24hour day. Both groups seemed to swear about their own regimes, so I suppose it is what seems comfortable to your lifestyle when you sleep/ awake, eat and if you take medications/ supplements. It might also depend on what dose of T3, and size of the pill/dose you can actually get hold off . Mine is 25 mcg and I was rather cautious introducing it to my T4 regime, some suggested dividing into 1/4, another into 1/8 for the first two days. I find the vitD dose proves the most problematic re timing, being told it should be with the meal with the most fat (my evening meal at 8pm) but then leaving 4 hours gap till taking Thyroid meds. I shifted my T4 only, in middle of night, to early morning when it is light and I can actually see the my tiny piece of chopped up T3 pill too!

Finola profile image
Finola in reply to Judithdalston

With regard to d3, my understanding is that if the d3 is delivered via an oil filled gel cap, usually olive oil, this provides all the oil necessary for proper absorption. So you can take it in the afternoon/evening with whatever you normally eat then.

Judithdalston profile image
Judithdalston in reply to Finola

I have taken high dose D3 daily for about 3 plus years initially took a 10,000 iu oil type capsule daily, then a 5,000 hard tablet - both swallowed after my supper but I was never aware they might behave differently in my gut. But despite these large doses I am still lowish on Vit D in my blood (90.1 nmol/L in range 50-200), so now swopped to an oral dose of drops that contain D3 and K2 ( mark 7), that gets absorbed in the mouth, so it's not so problematic with the 4 hour window between taking Thyroid meds. I won't have bloods taken for another 5-6 weeks so I won't be able to see the difference till then. Incidentally I choose drops so I can alter the dose more easily- you can't chop up an oil capsule! I noticed a negative review on Amazon re the popular spray variant: the spray action stopped working (give me a spray/aerosol and it will get blocked).

SlowDragon profile image

If taking vitamin D mouth spray by Better you it’s not so critical when you take it as it by passes gut

Shown to be very effective way of increasing levels too

Thanks everyone. I guess if the 8 thing isn't true, I'll take it at night with my T4. Taking it in the morning isn't really an option as there isn't enough time from me waking to going to work to be able to leave an hour before breakfast.

The vit D I take is liquid form via a dropper, so not tablets. Would I still need to move it?

Trying to figure out a way to take everything is like a military operation!

Hylda profile image
Hylda in reply to ceedee81

I’m with you there ceedee. I have to take Levothyroxine, Flecainide and various other heart drugs in the morning. Ok if I need the loo in the night, pop my Levo then, but Flecainide also has to be taken on an empty stomach or an hour before food. Then I start again in the evening!!


Could you PM me your T3 source please?

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