Thyroid UK
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Changing the Timing of Thyroxine Ingestion

Changing the Timing of Thyroxine Ingestion

The questions about when to take levothyroxine keep coming - and that is not surprising! The Patient Information Leaflets, most written information, doctors, nurses and most everything else is so stuck with taking levothyroxine in the morning, it isn't a matter "thinking" that it is right. It is a matter of not even questioning it. Not having the slightest notion that there could be an alternative.

This paper is one of several which suggest that, at least for some people, taking at bed-time could make a difference - in this particular case, a profound difference.

This is not the answer for everyone. Some do well - some seem not to do so well.

Marked Improvement of Levothyroxine Malabsorption by Simply Changing the Timing of Thyroxine Ingestion in an Adult Woman With Hypothyroidism After Radioiodine Therapy for Graves’ Disease

Yoji Miyoshi

Corresponding address: Division of Endocrinology, Diabetes and Metabolism, Sayama General Clinic, 4-15-25 Irumagawa, Sayama, Saitama 350-1305, Japan

Manuscript accepted for publication December 13, 2012

Short title: Timing of Levothyroxine Ingestion



We report the case of a 37-year-old woman suffering from hypothyroidism resistant to oral levothyroxine (LT4) substitution after radioiodine therapy for Graves’ disease. She was admitted to our endocrinology clinic for persistent hypothyroidism despite administration of full-dose LT4 (175 mg/day). The patient complained of severe general fatigue, leg edema, and body weight gain. Her serum free thyroxine (FT4) and thyrotropin (TSH) levels were 0.64 ng/dL and 58.0 mIU/L, respectively. Extensive investigations excluded disease of the small bowel, liver, and pancreas, as well as drug interactions. She also had no gastrointestinal diseases (for exmple, ulcer, inflammatory colitis). We were also able to rule out failure to take LT4 and concomitant use of other drugs. One month after changing the timing of LT4 ingestion from after breakfast to before breakfast, her serum TSH level did not decrease and her serum FT4 level increased from 0.64 to 1.02 ng/dL. The symptoms of hypothyroidism remained unchanged. We then changed the timing of LT4 ingestion from morning to bedtime. One month later, her serum TSH level had normalized and signs of hypothyroidism had disappeared. This case emphasizes the clinical importance of the timing of thyroxine ingestion in not a few patients with hypothyroidism resistant to LT4, although the reason for the malabsorption in this patient remains unclear.

Keywords: Hypothyroidism; Malabsorption of thyroxine; Timing of thyroxine ingestion


12 Replies

Wow - that cases study is impressive is it not!



It is a quite astonishing case.

However, what a pity that the mechanism was not identified. That might have made all the difference to so many people.

I also wonder if there might not be other patterns of dosing that could be appropriate for some. We have, after all, seen some people write of their use of various split-dosing regimes.



my t4 and t3 work better taking it at night and I believe I absorb it better


I take mine at night and gave noticed a vast improvement it's not for everyone but it works fir me.i also do not eat for 2hrabeire and after taking my levo,I was also told turnip/swede and cabbage can upset some people akso don't take any accelerants such as coffee tea red bull pro plus or green tea as all can effect the levo


I wonder if it's a case of taking levo on a really empty stomach - which clearly it's going to be overnight, progressively so.

Also, diet may play a part. If, say, calcium interferes with levo absorption, and a person consumes a lot of milk (maybe even milk in tea), then for them levo at night might be better, as far away from calcium (or any other food interference) as possible. What does the team think?


I started taking it at night quite a while ago and never looked back it works for me on so many levels

I have no doubt Rod that some scientist will pick that paper up and do further investigation into it if not the actual author of the paper.

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After reading on here, (Thyroid UK, ) about members changing their timings, I too thought I'd give it ago several days ago, after having lots of new bloods taken (incl. vit B12, + Vit D rechecked. + others ?) haven't got the results back yet.)

Last time I was upped from 50 to 75 on my Levo and prescribed Vit D to help the Levo (so I knew I wasn't absorbing the correct amount of Levo my body needed)

I now take my HRT early in the morning a couple of hours away from food, then my prescribed vit D with my mid day meal, (believe Vit D needs to be taken with food to be absorbed better ?) Then my 75 Levo around 10pm. on an empty stomach.

I might be dreaming, but even after only a few days I now feel clearer headed, not so tired, have more energy and my sudden all over sharp pains I have not noticed, in fact I can't remember the last time I hurt.

Only time will tell.

Nice dream while it's lasting ;) :)

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My endos (in Diabetes Unit) never saw fit to mention T4 should be taken an hour before or after food and that it shouldn't be taken with supplements or other meds.

The hospital pharmacy recommended taking it a.m. because absorption is supposed to be better.

I think morning meds are recommended because its supposed that compliancy is better rather than efficacy of absorption.


I switched to the evening because it suits me and I have never looked back


I take my with anti depressants,vits etc in the morn is that wrong


Don't think it that it is "wrong" - far better to think, could there be a slightly better way of doing things?

Because levothyroxine binds to large numbers of other things - for example, many foods and medicines - you might be absorbing less of the levothyroxine you are taking than than might be possible.

Many people suggest that this automatically gets countered by being given a higher dose - because it will take more to reduce your TSH to an acceptable level. This is imperfect because on the one hand, it is very difficult to always have exactly the same amount of "other stuff" going into your stomach at the same time every day. You might change the other tablets you take.Or skip breakfast.

And for reasons that are not 100% clear, people do seem to feel better if they are on the minimum dose, but well absorbed.

Timing is something that many people have changed - some to good effect, others feeling worse by doing so.



A TUK poll says 12.8% take their meds at bedtime.


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