When to take levothyroxine

It has always been rather assumed that people on levothyroxine should take that medicine first thing in the morning, before breakfast. Indeed a typical manufacturer's documention says something like:

...preferably taken before breakfast or your first meal of the day.

No reason is given. No hint as to how long before the first meal. It appears to have been something of an assumption with no proper research.

Some research has suggested that bedtime is acceptable, and may even be preferable.


I'd say that like most things, it is likely to depend on the individual. This view appears to be supported by the varying choices and responses to two polls we have hosted right here:



16 Replies

  • Until recently when I discovered this site I had no idea even about taking on an empty stomach! Just thought it was the norm to take in the morning and luckily I don't drink coffee first thing often. Hadn't even occurred to me about other meds at the same time. Really interested to hear people's thoughts and experience so thanks for pulling this together

  • Exactly why I did it. Thanks for responding. :-)

  • I wonder if the same holds good for NDT. The Chinese study seems to imply it is also better taken at bedtime. I should give it a whirl

  • Well, the only way to find out is...

    If you do, I wish you well. Take care.

  • @helvella

    I'll try it out and report back at a later date - I am not at my best in the evening as I often fall asleep on the sofa till small hours - adrenals perhaps or just the effects of hard physical work at 58 - so timing might be a challenge but I am not exactly dynamic first thing in the morning either 😴 but manage to drag myself out for 6am 6 days a week, sometimes forgetting to take the tablets before I leave the house - I always have a stash on my person for this eventuality! I never eat till midday, but can't resist a coffee 1st thing. What inexplicable and bizzare subconscious priorities I have!

  • Doppio espresso, si prega di. :-) ☕☕

  • I did try Levo at night though stopped and back to morning for holidays as eat later then but I did feel a little better taking at bedtime.

    I'm now on NDT and never thought to try evening! I don't sleep well or drop off straight away and can't get back!

    So not sure changing time will help but will certainly think about it!

  • My post is certainly not meant to be any sort of recommendation - just a very minor bringing together of some information/links.

    (I don't change the time I take my levothyroxine - always at bed-time - so why should anyone else change theirs? Only change if you think there is a reason to do so.)

  • Was just thinking as I sleep badly it might help! You never know!!!

  • Give it a go - it might work. As long as you miss it the night dose before a blood test and take afterwards and night dose as usual. :)

  • I know of people who take it at night and do just as well (or even better) than when they take it first thing in the morning.

    I personally think consistency is key. For some reason, I find it easier to remember to take meds if I take them in the morning, but that's just me.

    Since T4 has such a long half-life (+/- a week), it really shouldn't matter when you take it. As far as I know, T4 is practically inactive, and needs to be converted to T3 by the body, a process that takes time.

  • However that view, whilst initially looking perfectly sensible, doesn't make quite so much sense when you take into account the fact that about 48 hours after talking levothyroxine is when you get the peak T3 impact of the dose. (That would back your suggestion of the importance of consistency. I agree.)

    Reaction to levothyroxine seems to be quite variable. I have often reported that I have witnessed the effect in someone else within a few minutes.

    Seems to me that this is yet another situation in which the variability among us is enough to make generalisations very difficult.

  • Something I've been wondering recently about the gap either side of a dose to allow for an empty stomach.

    I'm considering adding a third dose of NDT to my day, as recently went to two doses and got surprising improvement. But as I'm only awake for as little as 10 hours, it's hard to build in the amount of fasting necessary.

    So I wonder what happens if we do take a dose close to food. Is it a clear percentage reduction in the effectiveness? Or something more complicated? If it's the former it would be fine just to take a slightly higher dose and do the same thing every day.

  • I don't think it can be a clear percentage.

    The time that food spends in the stomach, and then how long it passes through the parts of the intestine which mainly absorb levothyroxine are variable. That is, variable within an individual, from day to day, as well as between people. Add on that different foods will have their own varying effects, you are unlikely to achieve even absorption.

    At the same time, most reports suggest a modest percentage change in total absorption - it is not as if we expect, say, a fifty percent change.

    Do your best. Adjust your dose. And hope.

    The most important thing is to have realised that food can affect thyroid hormones.

  • On the point of knowing how far in advance of breakfast to take meds I have noticed that I experience an increased feeling of energy about 20 mins after taking my NDT. So, while I do stay in bed one hour after taking my pill (about 6:00am), I get the feeling that 20 mins would do in a push. I automatically awake at 6:00am, go pee and take pill, get back in bed and watch the morning news for one hour and get up at 7:00am. Seems to work out nicely - especially that the morning news seems to be repeated throughout the day so I don't waste a lot of time watching TV - unless, of course, if there is CNN "breaking news" - which 9 times out of 10 isn't.

You may also like...