Q&A. Dosing T3 in light of circadian rhythm

[Post updated Aug 5, 2020 with additional sample images.]


In response to my post The Significance of the TSH-T3 Circadian Rhythm, Julien wrote:

“Thank you for such an informative article.

If I interpreted this correctly, for the hypothyroid patients on combined T3+T4 therapy, it would seem that taking the T4 dose early in the day and taking most of the daily T3 dose in the evening would help the body match the normal circadian rhythm of these hormones.”


Good question, Julien. Thyroid therapy is never going to totally mimic the natural circadian rhythm, but we can certainly try and see if it boosts our health.

This is going to be a long answer. My two recent posts on the circadian rhythm focused on the “healthy thyroid” and people who are not yet in need of interfering with natural rhythms by using thyroid medication.

That’s why I’ve made my reply a new post–so I can talk about the differences in thyroid therapy.

  • Tania S. Smith

Timing a levothyroxine (LT4) dose is more about absorption than circadian rhythms

If you take synthetic T3 and T4 separately, rather than desiccated thyroid (NDT) in which they are combined at a fixed ratio, don’t worry about the timing of your Levothyroxine (LT4) dose. There is no need for a daily peak in FT4 levels. There’s only a tiny FT4 rise within 4 hours after a dose, and it’s hardly a blip on any circadian rhythm map.

With T4 dosing, it’s almost all about maintaining a steady absorption rate from day to day by NOT taking calcium, magnesium or iron or even coffee too close to it (the list of interferences is huge: check a recently-updated product monograph like Eltroxin, page 17). Many people even take T4 at bedtime and find improved absorption.

Create a T3 24-hour rhythm.

In Russell’s 2008 research article, they found that ““FT3 levels peak approximately 90 min after TSH levels at around 0404 h and remain above the median level from 2200–1000 h.” — so being above the median (average) daily value usually occurred between 10pm and 10am.

The MAIN key is to try to make your T3 dosing “rhythmic” on a daily basis. It ought to be

  1. Distributed enough (not just one dose a day in a big pulse) and
  2. Lopsided enough (with some down-time vs. a peak dosing window, and some tapering off). If you dose without enough of a daily break from T3 dosing, the body can get confused about the lack of rhythmicity and not know when to sleep.
  3. Respectful of night-time or “pre-waking” hours. This dosing window is an extremely powerful and helpful place to dose T3, but managing it in the context of sleep disorders and conventional schedules can be a challenge.

Working with these principles, use safe and cautious experimentation and measuring to place the T3 dosing rhythm where it fits your body’s other rhythms the best.

NOT circadian: One T3 / NDT dose per day, or LT4 monotherapy

Before I give dosing examples in further images below, I want you to see what happens if you are a hypothyroid patient who is NOT dosing with the above FT3 circadian rhythm in mind.

  1. If you were to take only ONE T3 dose per day, 10 mcg, on top of a daily dose of LT4 taken at the same time of day.
  2. If you take NO T3 doses and are just on standard LT4 monotherapy.

In this graph, the 0.00h is when a daily dose is taken and 24.00 is just before the next daily dose is taken, regardless of the time of day.

As you can see, on standard LT4 monotherapy (blue-green dots on the line) the FT3 levels are relatively flatlined. The little rise and fall is mostly due to T4-T3 conversion rate changing, and because FT4 levels rise a little by 4 hours post-dose.

If you are taking LT3 + LT4 (or desiccated thyroid NDT) and if you only take one dose per day, there are two ways it does not match circadian rhythm:

  1. There will be a higher peak FT3 that may confuse your pituitary gland and over-suppress TSH levels (making your doctor think you are overdosed when you are not), and
  2. Even if you were to take the single LT3 dose before going to bed, the peak FT3 is short-lived and then falls to baseline. It may not sustain itself long enough to work in synergy with other hormone peaks during the night.

A fabulous resource

Paul Robinson’s “Circadian T3 Method” (CT3M) — a book and some of his blog posts at paulrobinsonthryoid.com — discusses many of these rhythmic factors, dose timing and dose strength, and how to measure your vital signs.

A lot of the decision-making wisdom he offers about dose timing is based on the principle of supporting the natural circadian rhythm of cortisol and other hormones with the T3 dose you are taking.

His book on CT3M and its principles can be adapted to a person taking only a little T3 with mostly T4, even though it is written for those like me on 100% T3 monotherapy.

People who use Paul Robinson’s protocol tend to

  • start dosing in the early morning before rising from bed (like half way through the night or 3-6:30 am if rising at 8)
  • then taper off with smaller doses or no dose in the evening,
  • then give the body at least an 8 hr rest from T3 dosing.

Building doses gradually on each other produces a “cycle” whose peaks are weighted on half to 3/4 of a 24-hour period.

Samples of dosing for FT3 rhythms

This section shows you images of example dosing to rhythms for

  • T3 monotherapy
  • Desiccated thyroid (NDT)

T3 mono: Unique elements

If you are taking fast-release LT3 alone, you may need to take one or two smaller booster doses or, a microdose through the mid-day to ensure distribution (not letting your T3 levels plummet too far) while creating the overall lopsided effect of a sine wave curve. Without much if any FT4 in circulation as a foundation, there is little to no baseline T4-T3 conversion as a cushion to fall on.

Option 1 : Daytime peak

The peaks will shift accordingly depending on the strength and timing of your doses.

Option 2: Pre-midnight peak

As you can see, the model is not perfect in the image below, where the 8AM purple line does not align on both sides of the image as it should.

Nevertheless, even this misalignment at 8am visually represents the subjective experience of some patients: A strong FT3 at night seems to endure longer into the next day without symptoms of hypothyroidism. This may be because of T3’s synergy with other hormones near their peaks.

Option 3: post-midnight peak

Another way to do it is to time-shift the rhythm quite a bit to approximate the daily FT3 peak and valley of Russell’s group of 29 people with healthy thyroids. You’d dose to build up levels at 6-9PM and then, around midnight, dose to create your highest peak during the night, and then allow FT3 levels to taper off by 9-10AM. It’s not a perfect approximation.

Desiccated thyroid (NDT): Unique features

If you are taking desiccated thyroid (NDT), some patients have reported having a more gentle slow-release effect. This may be due to its being bound to thyroglobulin rather than sodium in the tablet.

Therefore, depending on how your body absorbs it, instead of having a peak FT3 level 2.5 or 3 hours later, it may gradually rise to a lower peak 4-8 hours post-dose depending on absorption. Note that the estimates below are based on anecdotal evidence of the gentler effect of the T3 from NDT, since we do not have any published studies on desiccated thyroid dose pharmacokinetics.

Option 1: two doses

On two doses, it’s challenging to build to a single peak per day without layering like this. Evenly spaced doses will create a two-peak day. The model above puts the lowest point of the day at 4pm when Russell’s model places it from 10am to 3pm.

Option 2: Three doses, midnight peak

Three doses offers a little more flexibility. You could have two smaller doses and one large one, or one small and two large.

Make your own plan. You could try drawing your own graph on a piece of paper. Get out a pencil and a ruler. Put the timeline on the bottom. Create either dose-response curves (from the 10 mcg LT3 Saravanan image above) or approximate angles that peak. Consider your lifestyle factors, your sleep challenges, and how much of Russell’s 2008 circadian rhythm graph you want to try to imitate.

Perfect mimicry of “the healthy norm” is not required. A little time-shifting is ok.

In Russell’s 2008 study of circadian rhythms, mild time-shifting was normal. Some people had TSH peak 2.5 hrs before the FT3, with: “20 of 24 subjects showing peak correlation [between TSH and FT3] at between -0.5 and -2.5 h, suggesting that FT3 lags behind TSH by these amounts.”

Dosing thyroid hormone is never going to mimic nature 100%. It is not like having a healthy thyroid that secretes directly into your bloodstream every minute of every day, at a flexible rate, on top of a flexible T4-T3 conversion rate across all your cells.

A pattern that works for many patients taking T3 is often a little time-shifted forward or backward from the natural FT3 circadian rhythm peak, simply because nobody enjoys waking up just to take a pill so that it will peak in bloodstream 2.5 to 5 hours after taking it.

It’s not necessarily a major problem to have a daily T3 rhythm that is time-shifted away from what you see in “healthy-thyroid” people who sleep approximately 10pm-6am, eat three meals, and work during the day.

Why is it not too damaging? Because even in health, the TSH peak can time-shift if you’re a shift worker, a project-based worker, or in a northern or southern region with different day lengths over the year. When we travel overseas to a new time zone, our bodies can adapt, though we do pay a price.

Nevertheless, consider a night-time T3 dose and/or a pre-rising dose.

If you want your FT3 to peak at the time other hormones need it or expect it to arrive, you may choose to be the servant of your body’s needs, despite the inconvenience of aiming for nighttime above-average FT3 levels.

You can force your body to wait 3-6 more hours for your T3 peak to arrive, or you can force T3 to peak a little earlier than it would in perfect thyroid health, but your other hormones might not be very happy with you.

A multitude of our hormones adapt to daylight and sleep schedules, not just TSH and FT3. Shifting your T3 dosing schedule to conflict with your sleep and circadian rhythm may disrupt your melatonin rhythm, cortisol rhythm, and other rhythms.

Our circadian rhythms are synchronized through our central “CLOCK” gene in the hypothalamus (Hastings et al, 2018), which communicates with other organs and glands to orchestrate their function. Each organ has its own clock. Just imagine how many 24 hour sine waves our bodies naturally manage! This is a growing field of medicine, and more science articles have been written on it since 2015.

In Jansen’s 2015 study of longevity, which I reviewed in my Circadian Rhythm Part 2 article, the people who had a parent living over age 90 had the most “prompt” and timely response of FT3 when the TSH rose during the night.

Nowadays, you can purchase devices that create a silent vibrating alarm on your wrist, and you can put a glass of water and pill on your night table as you go to bed.

Try to estimate roughly how many hours since rising, or after bedtime, your TSH would have risen if you were not dosing thyroid hormone.

  • If you go to bed at 8pm and rise at 4am, shift your T3 dosing to enter your body 2.5 to 3 hours before your desired FT3 peak hour(s).
  • If you go to bed at 12pm and rise at 8am, shift your T3 dosing to match accordingly.

As for the health risks of breaking up your sleep schedule just to take a pill, risk is more about how many hours per day you get, not about whether you break up your sleep into shifts.

“Both short and long sleep durations are significantly associated with increased risk of coronary heart disease.

Compared with 7h sleep duration per day, the risk of coronary heart disease increases 11% for an hour decrease and increases 7% for an hour increase.”

(Wang et al, 2018)

Time for a disclaimer — There’s no promise that a night-time or pre-waking dose will work miracles for you. It won’t immediately make your dosing optimal. It certainly can’t cure an underdose or overdose. Of course, it may create challenges for people who have sleep disorders. But it might actually help you sleep, since the nighttime T3 is natural. It might boost your health in unexpected ways by supporting other hormones’ 24-hour rhythms. Your body might want you to at least give it a try.

Evening and night responses to T3 dosing vary

Response to evening and nighttime T3 dosing varies among patients who dose various T4-T3 combos, or desiccated thyroid, or people on T3-only.

It’s extremely individualized because we each have unique metabolic handicaps.

  • Some people have trouble sleeping if they take a dose too close to bedtime, but others find that a bedtime dose helps them sleep (because T3 is only a stimulant in certain metabolic circumstances).
  • Some find that running out of T3 during the night makes them wake up with insomnia or tormenting anxious thoughts.
  • Some people, like myself, take the first T3 dose of the day well before rising from bed. Paul suggests 1.5 to 4 hours before rising, but my first T3 dose (I take 4 or 5 per day) is sometimes more like 5-6 hours before rising when I’ve stayed up too late the night before.

Take daytime doses as needed to cover “gaps” in your schedule.

You’ll learn when you need even a small dose if you start to feel drowsy or lose the ability to think clearly during the day, become cold, or get a slow heart rate.

  • If you dose 5 mcg pill per day, you can split the pill and take 2 doses of 2.5 mcg spread at least 6-8 hours apart, one of them during the night or before rising. (Note: In Canada, the 5 mcg pills are far more expensive per mcg than the 25 mcg pills. I’ve even split 25 mcg pills into 4 chunks of 6.25mcg with good effects).
  • If you take 15 mcg or more per day, you may do best to split it into 3 doses spread out 6-8 hours.
  • Some people without much, if any, T4 in blood while T3 dosing may even take more than 3 doses to prevent the “roller coaster” effect of huge rises and falls in T3 levels. It’s not wise to let the body “crash” with a too low T3 level at any time of day.

Know your T3 tool

Having a T3 prescription is a major biochemical tool, a blessing in disguise that can help us tweak many metabolic pathways.

Therefore, a fundamental piece of education is to understand the T3 dose-driven rhythm as a tool (see our FT3 Peaks and Valleys article, and T3 withdrawal article). I’ve offered some tips for optimizing flexible-ratio T3-T4 combination therapy, and research-based guides for optimizing T4 monotherapy are coming soon.

One of the T3 pharmaceutical’s strongest assets (which some doctors think is a weakness!) is its fast-acting nature, which goes hand in hand with its short half-life. It does not take long for your body to tell you if you’ve moved in the wrong direction, and if you make a mistake, you can just backtrack.

The FT3 peaks created by dosing will always be much higher than natural ones, even if you only take a small dose of 5 mcg.

Our T3-T2 metabolism and T3 clearance rates can be different as well (far more loss to two inactive types of T2 during the peaks).

Keeping a record of vital signs we can measure (heart rate, blood pressure, body temperature, symptoms) can help us tweak the dose strength and timing to see what works best for us as an individual, but sometimes even measurable biomarkers like our heart rate can be difficult to read.

The potency of the T3 tool

The T3 pharmaceutical is a potent metabolic tool, so be cautious.

Even without a change in your total T3 dose per day, Paul Robinson and patient experience attest that simply moving a dose by 15-30 minutes in relation to waking, sleeping or eating can shift what happens all over our bodies for the next 5 hours, or 5 days. Moving or changing the size of the first dose of the day (the overnight, pre-waking dose) can sometimes have the same impact as raising the total T3 dose per day, it’s that powerful.

If your T3 dosage tweak did not cause an immediate negative response, it’s wise to wait about 5 days for your whole body to adjust to any minor change. Some tissues exchange thyroid hormone with blood more slowly than others.

Splitting pills and spreading out doses is a valid strategy. Taking “too much” at once can backfire with hypothyroid-like symptoms as too much T3 gets quickly metabolized to T2 and other derivatives like Triac.

If you have overdosed a little and it’s causing thyrotoxic symptoms, keep Milk Thistle supplements on hand for safety because the silychristin it contains can mildly block MCT8 transporters from taking up too much T3 into cells (Jörg et al, 2016).

If you’ve been wise enough to keep your experiments small, a mildly thyrotoxic phase will only last 3-6 hours post dose, and rest assured that Deiodinase type 3 is our body’s “blocking” defense system for managing temporary T3 peaks.

On the other hand, sometimes too small a dose is not enough to respond to the physiological need at that time of day.

Why is it so tricky and individualized?

Each person has a different ideal T3 dosing rhythm not only because of genetic variation, but because of the variety of our disabilities. Our non-thyroidal circadian rhythms can become time-shifted and de-synchronized during thyroid disease and therapy.

“Optimal” therapy truly is individualized, even in 100% thyroid health and physical health. It takes time to learn what your body needs. Each of us has different physiological strengths and weaknesses.

Too many people become discouraged when they meet biochemical targets recommended by others and still aren’t feeling well (such as targets recommended by the Stop the Thyroid Madness group). Your thyroid disability is unique. Therapy is adaptive, not a rigid prescription that is the same for everyone.

Have hope, and move forward.

We don’t have to know it all, we just need to know our T3 tools and how to use them cautiously, know some basic circadian rhythm principles, and gradually get to know our individual bodies enough. It is our role to micromanage dosing schedules within the daily dosage our doctors prescribe.

My own T3 story

People who dose even a little T3 can learn a lot about how T3 dosing works from people who depend ONLY on T3.

I’ve learned a lot about T3 dosing through my own experience since 2016. I’m a rare thyroid patient, an oddball, on T3 monotherapy, and I’ve described it like being in a wheelchair. Of course, I’m not a representative of all T3 monotherapy patients. There’s a lot of diversity even among those who dose T3.

My T3 caution, my plea for sanity

I am seeing too many tragic failures of T3 monotherapy lately. Do not simply jump to T3 mono because you’re struggling to become optimal on your current T4-inclusive therapy.

I’ve seen some people confess to trying T3 monotherapy because they have become afraid of T4 hormone or Reverse T3 hormone, because of people spreading the myth that Reverse T3 “blocks” T3. Those are not valid reasons. This is not based on science.

There are even some people who recommend keeping RT3 to the lowest two digits in the RT3 reference range or below. That’s ridiculous and metabolically backwards, like wagging the tail of a dog to make him feel happy. Reducing RT3 is not a valid therapy target. Untreated hypothyroidism has an extremely low RT3; is the lowness of RT3 helping them? No, it’s a side effect of their low T4 state. I could go on…

This ill-informed RT3 fearmongering and RT3 targeting is truly harming people, and it makes me angry to see it!

T3 hormone is not a cure-all. It’s not like a supplement, not at all like dosing a vitamin. It shifts your entire body to a more limited and volatile thyroid hormone fuel source. Not very many people truly need T3 mono, and some people truly can’t adapt to it.

T3 mono is a last-resort and compassionate therapy for people

  • who are very poor converters of T4 hormone and/or
  • who have developed a rare adverse physiological response to T4 that cannot be overcome, and
  • who have the capacity to micro-manage their therapy wisely and safely, and
  • who deserve the guidance and support of a medical professional who meets the criteria of a good thyroid doctor.

Considering the option of T3 mono ought to involve careful planning and a very gradual transition, not a sudden switch. Once you’re there, it is still like balancing on the edge of a knife, and it takes a lot of work to manage safely.

Patient support groups

Thyroid Patients Canada now has a set of moderators for its own private patients-only support group. Our principles are “share wisely, seek evidence, and reason carefully.”

For Canadian thyroid patients only, see a very large, active and diverse group on Facebook called Canadian Thyroid Support Group.

Paul Robinson has a private Facebook group for questions about his latest book, The Thyroid Patients Manual. Another group on Facebook that is based on his T3-only protocols is called T3 Support.

For those not on Facebook, HealthUnlocked, mainly UK-based, is a good Thyroid-focused public message board.

Links to blog posts on thyroid circadian rhythm

[Part 1. Circadian rhythms of TSH, Free T4 and Free T3 in thyroid health, a descriptive overview of how the rhythm works, with tips on the timing of thyroid lab tests outside of thyroid therapy]
[Part 2: The significance of the TSH-FT3 circadian rhythm. How the TSH and FT3 response combine to create a healthy, individualized FT3-FT4 ratio that can sustain a person in subclinical hypothyroidism and in extreme old age.]

45 thoughts on “Q&A. Dosing T3 in light of circadian rhythm

  1. Thank you for taking the time to write such a detailed answer to my T3 timing question, I am impressed by the amount of new knowledge to explore on this site. I am so grateful that some people are sharing this valuable information that can have a dramatic impact on quality of life. I will also be following Paul Robinson’s work. There was another book which helped me learn a lot about the daily rhythms of our bodies: The Circadian Code from Satchin Panda – which mentions that the SCN is indirectly connected to pituitary, adrenals and thyroid gland. Thus it’s not so wild to speculate that adopting healthy circadian habits (sleep, meal timings, light exposure and exercise) might also improve the thyroid hormone’s circadian rhythms.

    I will be experimenting with my T3 timings and check for improved metrics on my sleep tracker report which includes heart rate, heart rate variability, deep sleep and REM sleep.

    1. Thanks for your reply Julien! Thanks for that book reference. I’m on a learning curve myself!

  2. Tania, in the early part of this detailed reply, you suggest Paul’s Robinson’s thrice-daily T3 regimen, with a 6 to 8 hour rest period. However, later on, you mention you yourself are taking four to five daily T3 doses. Please explain this more fully. Thanks.

    1. I took a dose every 4 hrs from 6:30a, 10:30a 2:30p, 6:30p, 10:30p in Winter. It worked out until I had to lower my dose for the summer, in June 2020. I’m in transition trying to figure out how to move forward with more of an emphatic circadian rhythm myself.

      1. That’s a lot of phone alarms! I notice none of these are middle-of-the-night, providing you an eight hour break for sleep between doses. That’s Paul Robinson’s suggested rest period. My rest period is between T3 doses at 2100 & 0300, six hours. How did you decide you had to ‘lower your dose’? Thanks, Tania. Certainly the circadian cycle has a great deal to do with our dis-ease.

      2. When I noticed that I’m feeling weak muscled or a little bit trembly, I start measuring my heart rate many times a day and keep track. If the overall average heart rate is creeping up significantly from my norm then I know that I need to reduce, especially in light of symptoms like slightly shaky legs when going down a flight of stairs.

      3. Hello thyroidpatientsca, what are the dosage amounts you take at each of those times? Also, do you mean you take 5 doses 4 hours apart (since the times you listed are not 5 hours apart)?

      4. You’re right — that’s an error in my comment. Thanks for pointing it out. I have now edited my comment to say “every 4 hrs.” Indeed, I used to dose every 5 hrs until I found it was spaced too far apart for me.

  3. Hello Julien,
    I have Hashimoto and conversion problems from the start. Now I take since 15 years 240 mg of NDT in 8 doses throughout the day. This means that I rarely have a noticeable increase in t3. The main thing told me, Dr. Herthoge in Belgium has to pay attention to his body temperature and then dose how he feels.
    Measure the basal temperature at 4 o’clock in the afternoon which should be 37 degrees then the cells work properly and when you wake up you should have a basal temperature of at least 36.7 then the body has had enough T3 to work overnight. When it gets very warm in summer, I decrease the dosage a little.
    Many greetings from germany

    1. Hi Alex, thank you for sharing your experience! I will proceed with this extra temp check in the afternoon!

      When I was on T4 only, my T4 blood levels were on top of the range and I used to have an average basal temperature of 35.6 when waking up. I did a genetic test which revealed that I have a deiodinase 1 gene defect that is associated with low T3. I then requested to test T3, which had never been checked, and it was bottom of the range. Now with 10mcg of T3 daily my morning temp is around 36.2 and I feel much better. I wish I knew this a decade ago but am so happy to feel better with some T3 now!

      I completed reading the CT3M book that Tania suggested and it was really helpful, I am now into another one from the same author called Recovering with T3.

      1. Thanks for sharing your experience Julien. I am interested in the deidinase 1 gene defect you mentioned. How did you get your doctor to test for it? Was he/she to genetic testing.

        I have always been a very poor converter of T4 with elevated RT3 – even when my FT3 and FT4 levels are at the bottom 1/4 of range. After years of trying different T3/T4 combos I am slowly transitioning to T3 only. It would be nice to have genetic screening to help validate going on T3 monotherapy. My integrative doctor is great but I suspect he is concerned about peer review from the the board of the medical group with which he is affiliated. Any treatement that strays too far from the norm risks being flagged for review. This is where the need to revise and broaden standard endocrine therapies is so vital. We are stuck with theraputic protocols that simply do not fit most patients -often doing more harm than good.

        I am also interested to hear that you are on 10 mcg of T3..do you take it as a single dose or split? Do you ever have any issues with afternoon fatigue?

        My transition to T3 monotherapy has gone smoothly but I do get tired in the aftenoon. When I try and include a tiny afternon T3 dose, I end up with adrenal issues the next morning -in part because I have a very exagerated Cortisol Awakening Response that has gotten worse since menopause. So for now sticking with a single AM T3 dose.

        Since perimenopause and menopause my thyroid hormone uptake has significantly decreased. I anticipate being on a rather low daily dose of T3 – about 13-18 mcg/daily. It is nice to read of someone else who is on a smaller dose. Prior to these last few years I always required large T3 doses, so it is a litle scary to be on such a small dose – yet at this point it is what I can tolerate given all the adrenal, autonomic, and low cellular metabolic rate issues I have.

    2. Hi Alex, I’m intrigued by your taking NDT 8 times a day. Are they done in equal doses, and how many hours apart? I have trouble with taking too much NDT or T3 at any one time, so wonder if smaller more frequent doses would work for me. I currently take NDT with very small T3 doses 3 times a day 5 hours apart. I will look at the Dr Herthoge site you recommended. Thank you.

  4. Hello Julien
    36,2 can be to little most people have values ​​that are too low perhaps you feel good but it can be better . Dr Herthoge, who treats me, is a third generation endocrinologist. The recognized best endocrinologist in Europe. He himself has an underactive thyroid. So he knows exactly how it feels to have too little or too much hormones. He helped me and prescribed NDT for me. When other endocrinologists get their dr. then later go to him again for a course in his medical school to find out more about the connections. If you want take a look at his website or on Facebook. You can read his books about hormone , and you can ask him in about hormones in english and france. http://www.hertoghe.eu/en/

    Best regards

  5. I’d estimate that I wake once in the morning around 4am, like clockwork, and that’s when I take my Levothyroxine and T3. Then I fall back asleep. Previous to that, for seven years, I was dosed over the top of the reference range in T4 just to get enough T3 to keep afloat. However, even overdosed on T4 I still had hypo symptoms, like coldness, hoarse voice, lowered cognitive function, and vertigo but I was functional. It greatly elevated my liver enzymes as well. My T4 levels were brought down to within the top of the range and my T3 levels drastically declined and I was debilitated for the next three years. Even then my Dr. kept saying my T4 levels were too high while ignoring my falling T3 levels with the slightest reduction in T4. That’s when I started to do some online research and look over my lab results from previous years to make the correlation.

    I’ve always been on 88mcg of Levo which put me at the very top of the reference range so when I tried to add a little T3 on top of 88mcg of Levo I didn’t feel well. I have reduced to 75mcg for one week and adding 5mcg of T3 around 4am with my Levo and 2.5mcg of T3 at 12 noon. I felt good the first two days of reducing the Levo combined with a total of 7,5mcg of T3 but now I’m really feeling that reduction in Levo and I don’t seem to be able to increase the T3 beyond 7.5mcg. Not sure if I should alternate days between 88 and 75 or just sit on the 75mcg of Levo with 7,5mcg of T3 and see what happens.

    Overall, taking the T3 at the same time everyday helps with the rhythm.

    1. Dear JrBorenz, thanks for sharing your experience. What you went through due to the dose reduction on Levothyroxine monotherapy sounds absolutely horrible. This misguided policy-backed decision stole away some of your most precious and vital hormone, T3. One decision based on upside-down biochemical priorities stole away three years of productive living. It’s absolutely tragic.

      I’m so glad you looked over your lab results and started to understand what was going on. It sounds like you’re doing the wise thing and experimenting cautiously, understanding what is too much of both T4 and T3 combined, and how to lower your T4 a little to accommodate your T3 within your therapy.

      Yes 4AM sounds like a reasonable time to take your dose. If it feels a bit heavy all at once you could try to spread it out, with 2.5 at bedtime and the other 5 at 4AM, and see if that is worse or better. Some people don’t get enough of a “wave” from a microdose of less than 5 mcg while in others, it’s a boost that the body notices, much like a little increase in T3 from a thyroid gland’s secretion.

      Alternating slightly different T4 doses every other day is a strategy that woks well in health for some people — I did it myself for many years on LT4 monotherapy. However, when I became very ill and my RT3 rose significantly above reference, alternating caused worsening symptoms every other day, since D3 enzyme was upregulated by my illness, and I was losing more T3 every other day based on the D3 enzyme’s fast response to the changing T3 signaling levels in the main nuclear receptor (Barca-Mayo et al, 2011, https://doi.org/10.1210/me.2010-0213 ). So that’s something to keep in mind.

      Another thing to keep in mind is that we often lose T3 during the colder months of the year, so you might need to keep an open mind about increasing T3 https://thyroidpatients.ca/2019/08/15/in-winter-everyone-gains-t3-except-thyroid-patients/

      Best wishes, Tania S. Smith

      1. Thanks for your reply. I had a rare hurthle cell adenoma at 27 after my symptoms were ignored starting in my teens, which led to a partial thyroidectomy and overt hypothyroidism. I”m now 40. Today I got out a journal and thermometer, noted the times I’ll take T3, and lines by the hour to report symptoms so I can adjust. I get the slumps from 3-6pm like I’ve been hit with a tranquilizer and the 4am wake up call with dreadful anxious thoughts so I’ll try to adjust my T3. It made sense after looking at the T3 circadian chart as to why the slumps occur when they do. I’ve been running on 39% out of 100% in T3 for several years and it finally put me on a medical leave from work due to debilitating and disabling symptoms so at this point T3 is not an option but necessary for me to live. A light bulb goes off in my head when I read your articles.

  6. Over a few weeks ago I went T3 only. I wasn’t getting on well with T4/T3 combo or NDT. I just used the T3 circadian midnight peak schedule to create my own. Since I usually fall asleep around 11pm-midnight I’m setting my highest dose at 11pm. I find that I’ve been taking all my T3 around the morning and afternoon and running out at night resulting in poor stressy sleep and waking at 3-4am sometimes 5am if I’m lucky. My next dose is at 7am since I eat at 730am. Next dose is at 12pm with lunch at 1230pm. Both of those doses are my smallest. Then I have another at 6pm which is my second highest dose. I’m trying four doses because my resting heart rate was elevated in the 90s and early in the morning when my T3 was low or in the evening it would get to 100-105. The elevated heart rate was making me feel wonky. I’m currently at 50mcg but without a functioning thyroid I suspect I might need more. One day I took 75mcg and felt good but still low and then it wore off by 3pm and I was so tired. When following the post midnight peak do you think it’s best to do increases on the evening doses like 6pm or 11pm? Thanks for the great article.

    1. JBorenz, Thanks for sharing your dose adjustments. I’d agree the 100-105 at rest in the evening is not a good sign, so maybe play with reducing the dose that occurs just prior to that happening, and see if it lowers. I am also coming across occasionally higher HR in the 5-6 hrs before bed, but I’ve usually had this happening at the end of a day of lower-than-normal dosing and sleep deprivation the night before. As soon as I go to bed, HR does not rise at all in response to bedtime dose or even waking up half way through my sleep cycle to take a hefty dose.

      I am thinking of adding to this post some scientific graphs I found on a natural “bimodal” heart rate 24 hr rhythm, so that we can use that normality to assess our heart rate. I’m going to make updates to the mountain images too. – Tania S. Smith

      1. Thanks for replying. After one day on my new circadian schedule I’m already making adjustments. I seem to do better with a pre bed dose which allows for a peak around 11pm-12am so I’ve moved a larger dose to 8pm and as I usually wake around 4am a second dose there. That gives 8 hours in between.Then waking at 7am like clockwork, and small doses following at 10am and 3pm. Although, I might end up moving my largest dose to 4am. This seems to be my body’s greatest hour in need for T3. My heart rate rises in response to a higher carb meal or sugar which may affect my blood sugar, when my T3 tapers off, or when I sleep poorly due to low T3. I find that my heart rate settles down after I take the T3. A heart rate 24 hr rhythm chart would be very helpful. The T3 circadian charts have been some of the most helpful .

      2. Thanks for sharing some of the results of your experiments! I’m still tweaking my own schedule and learning from my body’s response..

  7. Thanks for this valuable information on T3 dosing. Instinctively, splitting my T3 into 3 small doses made sense to avoid large peaks and troughs, however I felt like I was wasting expensive medication by taking a dose near bedtime. Now I feel happier knowing there is a genuine need for some T3 during the night.

    1. Thanks for your comment. Agreed. Yes there is an impression out there among patients and physicians that we need T3 more during waking hours, though I’m not sure why we would need it any less during the night. I think a lot of dosing advice has been based on convenience. Our bodies and brains are still using hormones as we sleep, and some of us may sleep better when dosing at bedtime (I do!).

      I would love to see the pharmaceutical development of an enteric-coated LT3 preparation that gets absorbed hours after we fall asleep, so that those of us who want to experiment with mid-sleep dosing don’t have to set an alarm to wake up mid-sleep to take a pill. – Tania S. Smith

  8. Hello, thanks for the informative article. I was dosing 3x20mcg T3 at 4am,11am and around 5pm. My doctor has reduced my T3 to 50mcg and added in some NDT. How should I dose now? Thanks in advance for your reply

    1. How much NDT? You can divide the NDT tablet, and disperse it among your T3 doses. Or just add it all to the first dose.

      1. Thanks Jenny, it’s only 30mg NDT atm and the doctor is going to retest labs in 6 weeks. I have been on NDT before (180mg) but no T3 then. It’s in a capsule, so should I take it with the 4am 20mcg T3?
        Thanks again

      2. Hi Alice, I wonder what the moderator of this site would say. Are you doing the CT3M method? I have read that some people add NDT to their 11am dose if they are doing CT3M (in order to keep the first dose all T3). Or you could try one of the methods mentioned on this page, to create a post-midnight peak. You’ll have to experiment to see what works best for you. It is really a really tricky process – I still have not landed on a stable dose of anything myself and it’s been a struggle. I also take replacement hydrocortisone, so that adds to the difficulty.

      3. Yes I think I’ll add it to the 11am dose. I have got Paul Robinsons books, so I will have another read. As I said I have been on either all NDT or all T3, but not a mix of th3 two.

      4. Hi Jenny, when dosing NDT + T3 in combination, here’s some tips:

        1) Calculate how much T3 is in each of your NDT doses, since every 60-65 mcg (1 grain) contains approx. 38 mcg T4 and 8-9 mcg T3. Then you can estimate the peak to go higher in blood for a larger dose. Feel free to take a combined dose all at once if you wish to boost the intake of T3, such as 15 mcg NDT (1/4 grain) plus a certain amount of synthetic T3.

        2) Also, consider that NDT provides T4, and T4 molecules can be absorbed poorly due to meals, coffee, calcium, magnesium and iron. So you’ll need to take those NDT doses 2-4 before and after absorption-interfering substances. Otherwise your true T4 intake per day may fluctuate based on the % of gastrointestinal absorption interference you had. You might want to try dosing your NDT at bedtime if that’s far enough away from food and supplements. Luckily T3 does not have any known hindrances to absorption besides cholestyramine (a bile acid sequestrant), so you can take it along with food and supplements.

      5. As T3 monotherapy for two years has not appreciably improved my condition despite many dosage adjustments, I’m considering adding back in some T4.

        I had quite forgotten that there are dietary & supplement restrictions. Is there a full list somewhere?

        2 to 4 hours before or after? Whew! I guess I have it easy–just four phone alarms!

        Thank you!

  9. Just happened on this informative blog.

    I have been taking 90mg a day NP Thyroid now for 6 mos. despite the potency recalls. I continue to struggle to figure out how it’s having zero effect on suppressing TSH (last few TSH levels were in high 4s – mid 5s) while my FT3 and FT4 remain mid-range. I take my dose in isolation several hours away from any other meds, foods or supplements. No Hashi’s. I’ve even tested taking my dose only a few hours before collection and my TSH is still over range (4.7).

    I’ve tried every conceivable combination of thyroid replacement for the last 12 years and I’ve never been able to get a consistently suppressed TSH with one exception: when I tried plain old T4 years ago and my TSH suppressed to <2.0 but my T3 was too low and RT3 went up too high so I switched back to desiccated.

    No one's been able to pinpoint what the issue could be. I'm reluctant to bump up the dose of desiccated much, fearing it will give me too much T3.

    Average TSH levels for last 2.5 years: 3.48. Now it's gone up even higher. I eat a LCHF diet, no more than 75g carbs. I am so envious of those posting TSH levels <3.00! Weight has gone steadily up over the last couple years also.

    Could this signify thyroid hormone resistance? I do have a T4-T3 conversion defect via decreased DIO2 enzyme.

    I am seriously considering adding T4 to NDT, just not sure how to ascertain the best ratio and calculate it.


    1. Thanks, for your comment, Mark. Sorry for the delay. I’ve been busy this term at the university so I had to leave our organization’s thyroid website without activity for a long time.

      Having both FT3 and FT4 at mid-range but a high TSH in the 4s and 5s sounds like the effect of the TSH receptor blocking antibody (TBAb). I have never come across any aberrations in pituitary TSH secretion due to diet or weight gain or DIO2 polymorphisms. It is comparatively easy for medications and substances to over-suppress TSH, but not very easy, and very rare, to see TSH inflate abnormally in relation to FT3 and FT4 combined. I had similar things happen to me. At one time, my FT4 was top of range with a FT3 of 4 (3.5-6.5) but then TSH suddenly plummeted and was almost suppressed. I don’t have a DIO2 polymorphism, but I do have two DIO1 polymorphisms. My TSH-obeying doctor reduced my dose from 112 to 100 mcg a day. My body’s illogical response to this tiny dose change was an unreasonably high TSH of 18.08 and an FT4 that was suddenly mid-range and FT3 below range. What makes me think it is not genetic pituitary-specific resistance to thyroid hormone (RTH) is the way your and my TSH fluctuate up and down. Genetics don’t make TSH secretion rates fluctuate and flip flop like that. My thyroid gland is atrophied, and atrophic thyroiditis is associated with the TSH receptor blocking antibody (TBAb).

      My tips: 1) Read my article on “Fluctuations and Remissions” 2) understand how the blocking / stimulating antibodies can affect the “ultrashort feedback loop” that tricks the pituitary gland. 3) See my article on the SPINA-Thyr analysis program and analyze your TTSI and TSHI indexes to see how the TSH relationship to FT4 wanders around at the same dose.

      This is an area of research that scientists ought to investigate further. It is only studied in case studies right now like the one by Fan, et al where a person was hyperthyroid, became hypothyroid, and experienced these bizarre high TSH responses to even a high FT4 during LT4 therapy. “Oscillating hypothyroidism and hyperthyroidism – a case-based review” https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4246140/

    2. Hi Mark.From the serious explanations of your results, in addition to hormone resistance, which you mention, TSH-secreting pituitary adenoma is also possible.
      But there is another and very funny explanation. One person experienced the same results when taking NDT. Since he is a biochemist by profession, he did a little research and found that the shell of grains is poorly digested in his body. After that, he began to take grains along with digestive enzymes and thus the problem was solved.
      Another woman came to the same conclusion intuitively. She, before use, erases the shell from each grain. Only after that NDT acts effectively in her body.

      1. I have since discontinued commercial brands of NDT such as NP Thyroid and now use a custom compounded encapsulated formulation with ascorbic acid as the only filler. Between the switch + increasing my dose to 2.5 grains (162.5mg), my TSH has finally suppressed to <2.00.

  10. Hello, sorry i don’t know where to post this but I’m desperate for some advice. I keep swinging hyper, for the past 18 months. Either the dose is too low or too high. Would splitting a dose (am and pm) affect me differently? as in less hyper swings? I feel like one dose a day is too much and maybe if i split my current dose 2 or 3 times a day might help? Sorry I’m not very knowledgeable but i’m trying to learn. Thank you for your time!

    1. Try dosing according to one of the charts on this article. Also, if you seem to be having trouble with a too-high or too-low dose, you could try alternating between them – one day of the lower dose, the next day take the higher dose.

    2. Hi Danny, sorry we’re so slow to reply to comments — we’re a volunteer-run group. Wow, there are so many possible variables that could be going on when “you keep swinging hyper” and your dose continually needs to be adjusted. It could be anything from fluctuating rates of oral hormone absorption to TSH receptor antibodies (if you’re an autoimmune thyroid patient) to T3 dose timing if you’re dosing T3, or something interfering with remaining thyroid function or pituitary TSH secretion. Here’s what could help — If you are on Facebook, we offer a patients-only peer support group where we share each other’s struggles, offer helpful tips and education, and we suggest things you could ask your doctor about. Click on the “Groups” link in our main menu at the top of our website.

  11. I love this article and have read it over and over! But I have a question in case I need to dabble in thyroid replacement therapy in the future. You mention that you’ve split 25 mcg pills into 4 chunks. Is it possible to split them into 8? I do not have enough context regarding the size of the pills and would appreciate being helped out in this respect.

  12. Dear​ ​THYROIDPATIENTSCA​ and Everyone ! ​
    First of all, thank you very much for this page , a lot of useful information, I appreciate it​! ​
    Sorry for my bad English, I speak the language poorly.
    ​Could you help me, please : when you think I should take t3, according to my biorhythm. I am a 45-year-old woman. I have had Hashimoto’s for 12 years.
    Unfortunately, I don’t understand the ​rhythm ​graph​ here ​, I know it’s absurd, but I never understand any drawings and I can’t even read a ​​map. :)​I’m not new to taking thyroid hormone, I’ve taken it many different ways, I’m trying to find the best version , unfortunately the doctors ​here in my country have very outdated knowledge .
    I have been taking thyroid hormone for 12 years, approx. 10 years ago t3 +t4 et, in separate tablets.
    I tried only t4 and only t3 a long time ago. It was illegal in my country, only approx. It’s been legal for 5 years, but I brought it ​”​in ​black​ “​before ..
    I am currently taking a total of 177 mcg of hormones: 140 mcg of t4 and 37 mcg of t3.
    I take t3 in 3 doses, but approx.10 years ago. My lab is very good​ now​, I think. tsh is 0, because of t3, t4 is in the upper range, t3 is also up.​ / Fresh labor : TSH : 0 , Ft4 : 19.4 pmol / L / 11.5-22.7 / ​, t3 : 5.5 pmol / L / 3.5 -6.5 /
    Reverz t3 is definitely high, I watched it several years ago, it was high even then.
    It could only decrease at t3.
    My current problem is that ​afternoon​ approx. At 4 p.m., I become very sleepy and inactive, and it usually stays that way until I go to bed. But I’m especially sleepy between 4pm and 8pm. I usually go to bed around 3 am because I work. I usually take the first dose of t3 + all t4 at 3 in the morning. 23 mcg t3 + 140 mcg t4. If I go to bed earlier, I take the first dose of t3 -+t4 at 4.30. But I often sleep so deeply that I don’t wake up at the alarm time and this is a problem, which is also why I go to bed too late, because I only work until ​am 01​, but I stay awake until 3 because of my​ hormone .​
    1st dose​, ​between 3 and 4:30​o ‘clock ​ in the morning.​ ​​ ​: 140 mcg t4 + 23 mcg t3
    2nd dose: 10 ​o’clock ​:10 mcg t3

    3rd dose​, afternoon, pm. 4.30 ​: 4 mcg t3
    I usually get up at ​am ​9 and I have to be active from ​pm ​10.
    I would like to change ​my​ work and bed time, I can do that, my work is ​somewhat ​flexible.
    I would like to get up at 8 and go to bed at 11:30 p.m.
    When should I take t3 to be active from 8 am to 11 pm?
    Today I changed the hormone intake, at 4.30 in the morning instead of 23 mcg T3, I took 15 mcg T3, I thought that the first dose might be too big​, it produces too high a t3 skipe and I would rather increase the 2nd dose. ​That was not good idea.
    I’ve never been so tired in my life, I’m barely alive, I couldn’t even start work, I just lie down and now I’m writing from bed. ​I slept very soundly last night. ​Now at 10.30 I will take 12. 5 mcg t3 at. (100 mcg – a tablet, I bring it in from Germany at an ​very ​ expensive price, because what you can get here makes me sick, and I can buy 100 mcg – and Thybon – which is cheaper than 20 mcg – Thybon proportionally)
    With this current amount of hormones, my body weight is also ideal, it took many years before it became good again.
    I just ​i would like​ to ask​​ for a recommendation/opinion from you, of course not with taking responsibility, since I know that every organization reacts differently to different times and we have to try it out ourselves. /

    Thank you very much for your answer​ in advence !​

  13. Maybe it has been mentioned already. I have a heck of a time splitting the 25mcg T3 into quarters. Hafling them is already pretty iffy, but it’s Lio dust from there on in. Any advice? I do use a pill splitter. Maybe it’s not a good one? And yes, the 25mcg is a LOT less expensive than the 5mcg. I’m on 10mcg a day (2×5) and thought I try the less expensive stuff but ran into the above challenge. Is the Merck brand maybe easier to split than the Teva brand, which I’m on? Thanks for helping me out. 🙂

  14. read this article with interest as up until about 3 months ago I was taking one dose of my t3 ie. 10mcg all at once with my T4. I wake up with terrible anxiety and haven’t been able to get rid of it since 2016 when I found out I had Hashi’s (probably a lot longer than when I found out). I am a terrible converter so added some T3 on advice from other sufferers but even on 10mcg my T3 levels are still lower in the range than they should be. Rather than increase my dose I decided to change the timing with the hope that it would help my waking anxiety. For the last 3yrs my sleep patterns have been out of sync due to noisy building works next door so I don’t usually go to sleep until around 3am and get up late morning. Thinking it would help my waking anxiety/higher cortisol levels, I take a 5mcg dose at around 4pm and then my second at around 2am and dropped my T4 from 125mcg to 100mcg as it was a little high in the range. I think I felt a slight difference in my anxiety not being so bad when I woke up as I take my first dose a few hours later than I did but to be honest I don’t think my current regime is working. It’s been 3 months now and I am due to test again. I am pretty sure I need a small increase which has been told to me by other sufferers on another forum for about 5yrs now. I am also sure my T3 levels are going to come back low and wondered the best way of dosing 3 times a day. Building works have finished and I try to go to bed earlier but still falling asleep at around 3am, set alarm to take my AD at around 8am, go back to sleep and then take my beta blocker at around 10.30am, doze off for a bit and get up around 11am. Any better suggestions on dosing for me please and should I test before I change my current regime

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