You’ve just come to your doctor for your annual check-up. Either you feel fine and you want to get a renewal of your current thyroid prescription, or you feel rather hypothyroid and you’re hoping to get an increased dose.
But your doctor says, “Your TSH is just below reference (or too low in reference). I’m going to have to reduce your thyroid medication.”
Your heart sinks. You predict months or a year of increased brain fog and fatigue.
You believe something else besides thyroid hormones is lowering your TSH, and science says you could be right.
If you believe there’s something you can do to increase your TSH by the time of your next test, science says you could be right about that, too.
If your TSH-obsessed doctor is not willing to learn about the vulnerability of TSH, you may want to try to manage your doctor’s prescribing behavior by managing your own TSH numbers.
It is so backwards to be focusing on the lower boundary of the TSH reference range during thyroid therapy. Thyroid hormones and the entire body’s response to them should be the main focus of therapy.
But because our broken medical system believes that wagging the tail (TSH) will wag the dog, some patients are left with no other option but “TSH test result management.”
In this post, learn 7 ways you may be able to prop up a lazy TSH to prevent a harmful thyroid dose decrease.
1. Recognize factors that can lower TSH
First of all, be aware of factors can lower the TSH besides your thyroid hormones. It’s more difficult or may be impossible to lift the TSH if these factors weigh your TSH down at the same time.
- Biotin. Health products for skin, hair, or multivitamins or B-complex vitamins can contain them. Biotin is a substance used in the chemical analysis of your blood sample, so if biotin levels are higher than expected, they can cause technical interference at the lab. Biotin’s effect is to falsely lower TSH numbers and raise FT3 and FT4 numbers (Block-Galarza, 2018)
- Vitamin A. Dosing 25,000 IU can significantly lower TSH by boosting the effect of T3 in pituitary and hypothalamus receptors. Vitamin A and its relatives is likely to have some effect even at lower levels than 25,000/day (Farhangi et al, 2012). A similar effect occurs with acne medications like Accutane that contain Isotretinoin (Sharma, 2006), which is a retinoid, a vitamin A derivative.
- Fasting or dieting of certain types. If you reduce total calories, cut back on protein calories, or change the type of fats you eat, you can lose leptin (Izadi et al, 2014). Lower leptin will lower hypothalamic TRH, which lowers TSH (Flier et al, 2000).
- “Drugs that lower TSH” — See the scientific article by Haugen, 2010. The most common offenders are glucocorticoids like hydrocortisone or prednisone — a lot of the chemical names end in “-one.” See a short list of glucocorticoids . See also the Synthroid monograph by Mylan, “Drug Interactions”, page 11. These lists are the tip of the iceberg.
- Central hypothyroidism. You could have a disability in the organs that secrete TSH. Check out my recent article on diagnosing central hypo while on therapy.
- TSH-disrupting chemicals and foods. Some endocrine disruptors focus on TSH, while others interfere with thyroid hormones. The TSH-specific chemicals are Phthalate, Perchlorates, BPA, Pesticides, PBDE. Bioactive foods: Caffeine, Fatty acids DHA and EPA (in fish oils), and Resveratrol (in red wine). Science is still evolving. See this recent article to find out whether they lower or raise TSH and by how much per dose (Olivera et al, 2019)
- Euthyroid doses of T3-dominant therapy, including desiccated thyroid therapy. Lower TSH is often a local side effect on the hypothalamus and pituitary, not necessarily a sign of excessive T3 and T4 levels in blood. Test Free T3 and Free T4 to see where they really are. Learn from Robert Utiger, the father of the TSH test, about how TSH responds differently in these therapies, plummeting quickly just before we achieve euthyroid levels.
Don’t obsess over this list too deeply. Do not go to extremes and starve yourself of vitamin A. Realize that science can only see a fraction of what can interfere with TSH.
Takeaway: TSH is a vulnerable hormone.
TIP: If you want to raise TSH, do what you can to reduce factors that push TSH down. Some of the factors may involve a long term change of lifestyle or avoidance of a chemical for weeks before the test. Do your research. Click the links to learn more.
TIP: If you can’t reduce or eliminate essential medications or remove unavoidable factors, make sure your doctor is aware of their TSH-lowering effects. Many don’t know.
Some of the tips below may still help raise the TSH.
2. TSH can be higher in the early morning.
Actually, TSH can be highest at 3 AM, but no laboratories are open to test your blood at that time of night.
Let’s look at how much TSH can fluctuate in 1 day in two different people.
TSH is the first graph below. I provide the other graphs to show the effects of TSH rhythm in people with healthy thyroids. (These people are not taking thyroid medication.)
Reference ranges that go with these graphs:
- TSH 0.35–3.5 mU/L | FT4 10.3–21.9 pmol/L | FT3 3.5– 6.5 pmol/L
If you have a TSH like the patient #27 on the left, your high rhythmicity uses 2.5 mU/L (79.3%) of the population reference range every day. Your TSH could be 1.0 and 3.5 on the same day.
It’s hard to know if you are a person with high rhythmicity or low rhythmicity, but there’s usually some degree of rhythm.
Here’s another graph from an earlier study (Brabant et al, 1990). They tested TSH every 10 minutes on a single day in ONE person. The peaks and valleys are very extreme and frequent.
CONTEXT: In the person depicted in the graph, “Sleep was allowed between 2300-0700 h with an average duration of 6h40 ± 0h40/rhythm. Meals were given at 0730, 1200, and 1730 h.”
TIP: Make an early morning appointment for your blood test.
TIP: If you do night shift work or sleep abnormal hours, consider how your circadian rhythm might shift. TSH might be lowest at a different time during the day than is shown in the graphs above.
3. TSH can be higher during sleep deprivation.
Safety notice: Please do not drive or operate equipment while sleep-deprived!
The 1990 study by Brabant and team tested the effect of sleep deprivation on TSH. They tested 3 conditions in 6 healthy males:
- acute sleep withdrawal (SW) during the 24 h of testing,
- normal sleep (S), and
- sleep after a night of sleep withdrawal (SAW).
The main thing that changed was the height of the peak TSH.
TIP: Your TSH may be higher if you did NOT get a good night’s sleep just before a morning blood test.
TIP: Don’t test TSH as you are recovering from sleep withdrawal.
4. TSH may be higher 12+ hours post-dose
It depends on what thryoid medication(s) you are dosing and how much you are taking.
The graphs below show two lines from the exact same patients on two types of medication.
- While taking more than 100 mcg of T4 only, they had their blood tested every 2 hours for 24 hours.
- Then they had 50 mcg of their T4 dose taken away, and doctors replaced it with only 10 mcg of T3. After they stabilized at that dose, they did the same 24-hour blood tests. Then they layered the line graphs on top of each other.
NOTE: These graphs’ time flow does not begin at midnight. The X axis at 0.0 is the time of a single daily dose. The 24.00 means twenty-four hours after a dose.
In the graphs above, reference ranges are fT3: 2.8 – 7.1 pmol / L | fT4: 10.0 – 24.0 pmol / L, | TSH: 0.3 – 4.0 mU / L.
On the T3-T4 combo they tested, the average TSH was 6.0 for part of the day. Obviously the experimental T3-T4 combo was an underdose. They took too much T4 away and gave too little T3 in exchange for it.
In the graph you can see this principle in people whose TSH is not suppressed by thyroid therapy:
- If you are dosed with T4 hormone (Levothyroxine, Synthroid, Eltroxin), you can lose a lot of your natural TSH fluctuation. TSH will be relatively flatter, but it will still change 12+ hours post dose.
- If you are dosed with T3 hormone (or desiccated thyroid / NDT which contains 20% T3 and 80% T4), your TSH can fluctuate significantly, especially if you are underdosed like these people and you are taking your T3-containing medication only once a day like these people.
Tip: Test 12+ hours post dose to increase chances of a higher TSH. Don’t take your thyroid medication after 8pm if you have an 8am blood test the next day. Take your thyroid pill after the blood draw.
Tip: IF dosing T3 medication or NDT, avoid testing during the post-dose Free T3, and try to spread out your daily dose to reduce its TSH-suppressive side effects. (See our post on managing Free T3 peaks and valleys.)
5. TSH can be higher if you don’t eat a meal right before the lab test.
Caution: Longer term fasting or calorie restriction can LOWER your TSH (Flier et al). Therefore, this tip is NOT about fasting or reducing calories on a chronic basis.
This is only about the timing of a single meal (Breakfast) in relationship to a blood test.
In 2014, Nair and team did a study on “postprandial state” (just after eating breakfast) and TSH levels. The experiment was simple:
- First, “Phlebotomy [blood sampling] was performed after an 8-12 hour overnight fast between 7:30-8:30 am for free T4 and TSH measurements.”
- Then, “the patients returned 2 hours after breakfast for their samples to be rechecked between 10:30-11:00 am on the same day.”
Before and during the experiment, nobody was taking thyroid hormones.
Results: TSH was significantly higher before breakfast. TSH was significantly lower after breakfast. Their T4 levels were unchanged.
Among the people tested, there were three subgroups. Before the experiment, Group A had normal TSH and FT4 levels, Group B had high TSH but normal T4. Group C had overt hypothyroidism, high TSH and low T4.
- Group A: pre-breakfast TSH 2.42, post-breakfast TSH 1.79
- Group B: Pre-breakfast TSH 7.53, post-breakfast TSH 5.35
- Group C: Pre-breakfast TSH 66.93, post-breakfast TSH 61.22
Is this effect just simply the circadian rhythm? Maybe. They should have tested other meals, not just breakfast, because TSH can have a steep decline between 6am and 12pm in people not taking thyroid medication.
TIP: Delay breakfast until after your early morning lab test to increase chances of a higher TSH.
6. On thyroid therapy, TSH can be higher mid-menstrual cycle
A study in two pre-menopausal women taking Levothyroxine monotherapy discovered that the mid-month rise in Estrogen created a significant rise in TSH levels. (Benvega et al, 2017)
The blood test was taken every day of the month at 8 – 8:30 AM over 36 months (3 years). They found a monthly rise and fall in TSH in two women aged 30 and 32 years.
Woman A on left, Woman B on right:
This happens because estrogen peaks just before ovulation mid-cycle. Day 0 is when the menstural flow begins.
It is well known in thryoid science that higher estrogen (estradiol) levels can increase TSH because it increases TBG (Thyroxine Binding Globulin). When TBG rises, it increases the percentage of T4 and T3 that is bound to TBG, and decreases “Free” hormone levels. Only “free” thyroid hormone can enter cells.
In women with healthy thyroid glands, there is not much of a difference in TSH because the body adapts: their thyroid gland can add more thyroid hormone to blood to keep Free T3 and T4 levels relatively steady.
However, in patients who can’t produce extra thyroid hormone from a thyroid gland, we can lose FT3 and FT4 without changing our thyroid dose. Even a tiny decrease can amplify the TSH. When estrogen peaks mid-month in females who have TSH that is unsuppressed, TSH can rise.
The main challenge is that it’s difficult to predict what day of the month the estrogen peak plus TSH peak will occur for each person. You might be able to predict it better if you measure basal body temperature, like people do when using the “rhythm method” to increase or decrease chances of pregnancy. You might have a monthly pattern that repeats, like these women. There are now smartphone apps available to track temperature on graphs to predict when ovulation occurs.
TIP: Take your blood test mid-cycle if you are a menstruating female to raise the chances of obtaining a higher TSH.
TIP: If you dose medication including estrogen / estradiol, be aware that it is a TSH-raising medication at the cost of lowering your Free thyroid hormone levels. Some foods also contain phytoestrogens that mimic this effect to a lesser degree.
7. On thyroid therapy, TSH can be higher in the coldest months of the year.
In 2017, Gullo and team did a study of a huge number of people’s seasonal TSH, Free T3 and Free T4 levels.
They compared people with healthy thyroid glands not taking thyroid hormones (BLUE) vs. people after a thyroidectomy who were taking thyroid hormones (RED).
Look what happened to the people who were on the same dose of thyroid hormone all year long.
This study was done on patients in Sicily in this climate:
- August daily temperature is between 19.3°C and 33.1°C
- January daily temperature is between 5.2°C and 15.5°C
What would the results be like in Scotland, or North Dakota, or Canada, or Norway, or Finland where the cold months will be colder?
They also found that thyroidless people on thyroid therapy lost a lot of Free T3 hormone in winter, while people with helathy throids gained Free T3 in Winter.
See my previous post with the fuller data set and discussion of Gullo et al, 2017: “In Winter, everyone gains T3 except thyroidless patients on T4“
TIP: If you test TSH once a year, test in the coldest month of the year. If you get TSH tested and your dose adjusted in summer, you may need a really big sweater to stay warm in the winter.
Is it worth it?
I’ve just listed 7 ways to increase chances of a higher TSH. It all adds up to this list.
Take your TSH blood test:
- After removing or reducing as many TSH-depressive factors as possible,
- As early in the morning as possible,
- After being sleep-deprived the night just before the test,
- At least 12 hours after taking thyroid medication,
- Before breakfast on the day you test,
- If you are a pre-menopausal female, mid-cycle,
- In the colder months of the year if you live in an extreme climate.
THIS IS RIDICULOUS, ISN’T IT?
Why would any thyroid patient be motivated to go to such lengths to try to inflate their TSH or avoid its suppression?
It’s because our medical system threatens to reduce our thyroid hormone supply based on a low TSH alone. Raising TSH can be a way to protect ourselves from harm within this broken system.
It’s because some foolish people in the 1990s put this moody hormone TSH on a pedestal and made it the sole judge of our thyroid dosing, and too many people have been afraid to question its God-like authority by pointing to the evidence.
If you step back and think about it, isn’t it amazing that TSH can vary as much as shown in the graphs above in response to some tiny nonthyroidal changes?
- TSH is a volatile, vulnerable hormone. It fluctuates based on factors way beyond your thyroid hormone levels.
- TSH often behaves very differently in people taking thyroid hormones compared to people who are not on thyroid therapy.
- TSH behaves very differently when dosing different combinations and ratios of T4 and T3 thyroid hormones.
- TSH fluctuations can sometimes be huge while our thyroid hormone dose does not change.
Why do medical systems grant this volatile TSH hormone the sole right to judge whether we have “adequate” dosing during thyroid therapy?
Our doctors have been given the power to starve us of thyroid hormone for a year just because our TSH is having a bad day.
We can be victims of our TSH and the medical system that idolizes it, or we can use science to try to master it.
If the TSH is abnormally low in context and we can’t do anything about it, a smart, evidence-based doctor can learn to recognize that and mistrust it.
Benvenga, S., Di Bari, F., Granese, R., & Antonelli, A. (2017). Serum Thyrotropin and Phase of the Menstrual Cycle. Frontiers in Endocrinology, 8. https://doi.org/10.3389/fendo.2017.00250
Block-Galarza, J. (2018). Biotin supplement use is common and can lead to the false measurement of thyroid hormone in commonly used assays. Clinical Thyroidology for the Public, 11(12), 3–4. https://www.thyroid.org/patient-thyroid-information/ct-for-patients/december-2018/vol-11-issue-12-p-3-4/
Brabant, G., Prank, K., Ranft, U., Schuermeyer, T., Wagner, T. O., Hauser, H., Kummer, B., Feistner, H., Hesch, R. D., & von zur Mühlen, A. (1990). Physiological regulation of circadian and pulsatile thyrotropin secretion in normal man and woman. The Journal of Clinical Endocrinology and Metabolism, 70(2), 403–409. https://doi.org/10.1210/jcem-70-2-403
Farhangi, M. A., Keshavarz, S. A., Eshraghian, M., Ostadrahimi, A., & Saboor-Yaraghi, A. A. (2012). The effect of vitamin A supplementation on thyroid function in premenopausal women. Journal of the American College of Nutrition, 31(4), 268–274.
Haugen, B. R. (2009). Drugs that suppress TSH or cause central hypothyroidism. Best Practice & Research. Clinical Endocrinology & Metabolism, 23(6), 793–800. https://doi.org/10.1016/j.beem.2009.08.003
Izadi, V., Saraf-Bank, S., & Azadbakht, L. (2014). Dietary intakes and leptin concentrations. ARYA Atherosclerosis, 10(5), 266–272. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4251481/
Oliveira, K. J., Chiamolera, M. I., Giannocco, G., Pazos-Moura, C. C., & Ortiga-Carvalho, T. M. (2019). Thyroid function disruptors: From nature to chemicals. Journal of Molecular Endocrinology, 62(1), R1–R19. https://doi.org/10.1530/JME-18-0081
Russell, W., Harrison, R. F., Smith, N., Darzy, K., Shalet, S., Weetman, A. P., & Ross, R. J. (2008). Free Triiodothyronine Has a Distinct Circadian Rhythm That Is Delayed but Parallels Thyrotropin Levels. The Journal of Clinical Endocrinology & Metabolism, 93(6), 2300–2306. https://doi.org/10.1210/jc.2007-2674
Sharma, V., Hays, W. R., Wood, W. M., Pugazhenthi, U., Germain, S., L, D., Bianco, A. C., Krezel, W., Chambon, P., & Haugen, B. R. (2006). Effects of Rexinoids on Thyrotrope Function and the Hypothalamic-Pituitary-Thyroid Axis. Endocrinology, 147(3), 1438–1451. https://doi.org/10.1210/en.2005-0706
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Categories: TSH hormone