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Can You Take Thyroid Hormone With Food? New Research on Levothyroxine Timing (2026)

June 30, 2026TfriedmanPosts
Can You Take Thyroid Hormone With Food? New Research on Levothyroxine Timing (2026)

Background

Thyroid hormone replacement therapy is the cornerstone in the treatment of hypothyroidism, yet the practical aspects of how and when to take these medications have long been debated. Traditional clinical guidance, without much evidence-based studies has emphasized strict timing—particularly taking levothyroxine (LT4) on an empty stomach and avoiding food and other medications to ensure optimal absorption. However, recent research and Dr. Friedman’s clinical insights challenge this rigid approach, suggesting that flexibility and patient adherence may be equally, if not more, important. 

The thyroid gland produces key hormones, primarily thyroxine (T4) and triiodothyronine (T3), which regulate metabolism and energy balance. In hypothyroidism, patients may be treated with several types of hormone replacement, including LT4 alone, LT3, combination therapies, or desiccated thyroid extract (DTE). Importantly, no single therapy works best for all patients, and individualized treatment remains essential. 

Historically, patients were instructed to take thyroid medications on an empty stomach, typically 30 to 60 minutes before breakfast, and to separate dosing from substances such as calcium, iron, and certain medications that could impair absorption. However, adherence to these instructions proved challenging. Studies have shown that up to half of patients find fasting requirements burdensome, leading to inconsistent dosing or missed medication. 

Recent clinical trial

A recent randomized clinical trial from Willems and colleagues in the Netherlands and published in Journal of Clinical Endocrinology and Metabolism in April 2026 explored whether levothyroxine could be taken with breakfast if the dose were adjusted. In this study, patients were divided into two groups: one taking LT4 in the traditional fasting state, and another taking it with breakfast with a 15% dose increase. The findings were notable—TSH levels remained stable in both groups, suggesting that the adjusted breakfast regimen was equally effective in maintaining thyroid hormone balance. 

Additionally, patients reported improved well-being and preferred the convenience of taking medication with food. Nearly 78% of participants who experienced both approaches favored taking LT4 with breakfast. Benefits included better adherence, a more consistent daily routine, reduced gastrointestinal discomfort, and overall improved quality of life. 

AI-modeling

Dr. Friedman used some AI programs and modelled thyroid hormone levels with and without food for LT4, LT3 and DTE. Modelling showed less of a peak in thyroid hormone levels after LT4 or LT3/DTE, less suppression of TSH, and more even levels of thyroid hormone levels throughout the day. While this is interested, it needs to be replicated with actual pharmacokinetic studies. 

Lessons learned

From a physiological standpoint, taking thyroid medication with food may produce more stable hormone levels. When taken on an empty stomach, hormone levels can peak significantly within a few hours, potentially suppressing TSH levels more than expected. With food, absorption is slower, resulting in more even hormone levels and possibly a more accurate reflection of thyroid function over time. 

Laboratory testing

Another important consideration is laboratory testing. Thyroid hormone levels fluctuate after medication intake, with free T4 levels rising by approximately 12–14% (and sometimes more) in the hours following a dose. For patients taking T3-containing medications, these fluctuations can be even more pronounced. As a result, it is generally recommended that blood tests be performed before taking the daily thyroid dose to capture baseline (trough) levels and avoid misleading results. 

For combination therapies or T3-containing regimens, timing becomes even more critical. T3 has a shorter half-life and leads to peaks in hormone levels approximately 2–4 hours after ingestion. This can transiently suppress TSH and complicate interpretation of lab results. Therefore, Dr. Friedman advises patients to delay their morning dose until after blood testing. When on DTE or T3-containing regimens, Dr. Friedman also encourages patients to divide doses throughout the day to maintain more consistent hormone levels. 

Clinical perspectives

Clinical perspectives emphasize that consistency is more important than rigid adherence to fasting rules. If a patient takes thyroid medication the same way every day—whether with food or without—dosages can be adjusted based on lab results to achieve optimal outcomes. This individualized approach prioritizes adherence and patient comfort over theoretical absorption concerns. Since this article came out, Dr. Friedman has been recommending taking thyroid medicines with foods and gives a higher dose; patients have been quite pleased. 

Summary

In summary, emerging evidence supports a more flexible approach to thyroid hormone timing. Many patients can take thyroid medicines with food, provided dosing is adjusted and consistency is maintained. With more experience on giving thyroid medicine with food, Dr. Friedman anticipates being able to say patients should take thyroid medicines with food. Blood tests should generally be performed before medication intake, especially for those on T3-containing therapies. Ultimately, successful thyroid management depends on individualized care, careful monitoring, and a focus on patient-centered outcomes rather than rigid protocols. 

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Update on Desiccated Thyroid

April 22, 2026TfriedmanPosts
Update on Desiccated Thyroid

Dr. Friedman frequently prescribes Natural Desiccated Thyroid (NDT), also called desiccated thyroid extract (DTE) to patients with hypothyroidism, especially to the 20% of hypothyroid patients on synthetic thyroid hormone replacement who still have hypothyroid symptoms, despite normal TSH values. Of the NDT products, Dr. Friedman prescribes either NP Thyroid or Armour Thyroid to his patients. NDT has other substances not found in synthetic thyroid preparations, and contrary to misinformation, are well-formulated products with excellent quality control. No NDT product is currently U.S. Food and Drug Administration (FDA)-approved, although Acella Pharmaceuticals, the manufacturer of NP Thyroid is completing a study that will be the basis for their FDA application. Synthroid and other L-T4 products were on the market for over 50 years before FDA-approval.


FDA Announcement

While on August 6, 2025, the FDA announced that it plans to remove all DTE, on March 11, 2026, the FDA issued a follow-up statement to DTE manufacturers. In this follow-up announcement, the FDA stated that it would “continue applying its risk-based enforcement approach to ‘unapproved’ animal-derived medications …,” while reiterating that it may “take action against a manufacturer that is not meeting quality standards and putting patients at risk.” This follow-up memo stated that the FDA will continue to allow DTE products to remain on the market beyond August 2026, while manufacturers pursue full approval of their DTE products as biologics.


We thank Dr. Makary and the FDA for their leadership in protecting access to DTEs for the 1.5 million Americans who depend on this vital medication to treat hypothyroidism. Acella Pharmaceuticals has been collaborating with the FDA since 2018 to pursue formal approval of a new DTE product. They remain committed to delivering a quality treatment that meets all current good manufacturing practices and FDA requirements.

CVS Caremark Announcement

However, starting April 1, 2026, CVS Caremark, a pharmacy benefit manager (PBM) that manages the prescription benefits for many health plans (including some Aetna plans), notified its members that they are removing DTE medications from its standard list of covered drugs. They did not give a reason for this decision, but Dr. Friedman suspects that CVS Caremark is pushing patients toward synthetic thyroid medicines instead of DTE products. This is not the first instance of CVS Caremark putting profits over patient care, as in 2019, they claimed that all doses of NP thyroid were on backorder, even though they were not.

Dr. Friedman encourages his patients to make their voices heard. If you are upset or concerned about losing coverage for NDT, you can tell CVS Caremark directly:

o Phone: 1-888-217-4161
o Email: customerservice@caremark.com

Alternatives for DTE

Fortunately, there are alternatives for DTE that may even be lower cost than insurance coverage. Dr. Friedman recommends you explore these options before suggesting Dr. Friedman change your thyroid medication, especially if you are doing well. Dr. Friedman recommends patients taking DTE and other T3-containing preparations twice a day.

Acella Pharmaceuticals offers a program called Vytal, with reasonable cash pricing. The following doses of NP thyroid are available at $69 for a 90-day supply including free shipping: 15 mg, 30 mg, 60 mg, 90 mg, 120 mg, 45 mg (15 mg + 30 mg), 75 mg (15 mg + 60 mg). Dr. Friedman frequently prescribes the 45 mg dose, so this is an excellent option.

The following are other options for obtaining NP thyroid:

Glendale Pharmacy
There are also coupons at GoodRx, WellRx or Optum PerksFor more information In case you missed it, Dr. Friedman’s webinar with Dr. Henderson entitled Dueling Academic-Based Endocrinologists discussing state of the art hypothyroidism diagnosis and treatment, September 14, 2025 is available at https://www.youtube.com/watch?v=hNx3ekkc0-Q or https://www.goodhormonehealth.com/webinars/ or https://www.facebook.com/goodhormonehealth
This webinar discussed the advantages of DTE and Drs. Friedman and Henderson’s view on why the FDA should not ban these products
Please contact our office at mail@goodhormonehealth.com or go to our website, www.goodhormonehealth.com for more information or to schedule an appointment.

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T4/T3 Combination

January 16, 2025TfriedmanUncategorized
T4/T3 Combination

Understanding Thyroid Hormones: T4 and T3

The thyroid makes two hormones, T4 which has a long half-life meaning it can be given once a day. T4 gets converted to T3 which is the active form of the hormone and has a short-half life, meaning it has to be given frequently. Most patients with hypothyroidism are treated with levothyroxine (L-T4), which is T4. There are many brands of levothyroxine that include Tirosint, Synthroid, Unithroid, and Levoxyl. As the thyroid makes both T4 and T3, doctors that give only L-T4 hope the L-T4 goes into “overdrive” to make up for the lack of T3 replacement and converts to T3. However, multiple studies have found that about 15-20% of patients on L-T4 replacement with a normal TSH level still have hypothyroid symptoms. Are you one of them?

Challenges with T4-Only Therapy

However, two very important recent articles suggested that about 15% of patients with hypothyroidism do not convert T4 to T3 properly and should be on a T4/T3 combination or on desiccated thyroid extract (DTE) that contains T4 and T3. I wish to highlight these papers as they are very interesting and important studies.

Study on T4 to T3 Conversion: The UK Research

One study came from the United Kingdom that looked at the prevalence of the gene that converts the T4 to T3. This is called the type 2 deiodinase. In this study, 15% of the population had an alteration in the gene that converts T4 to T3, the alteration is called a polymorphism. This polymorphism means the DNA is changed so that this enzyme works less effectively. The patients with this polymorphism required higher T4 dosing and had more psychological problems than those that did not have the deiodinase polymorphism. They did not examine whether these patients would benefit from T4/T3 combination and also did not actually measure the enzyme, they only looked at the gene coding for this enzyme.

Italian Study on Free T4 and T3 Levels

Another very intriguing article came out from Italy that initially examined patients that had a thyroid nodule but were not on a thyroid medicine and did not have any other problems with their thyroid. Examining several thousand of these healthy patients, they were able to establish normal values for free T4, free T3, and TSH in this Italian population. Once these normal values were obtained, the researchers then took patients that had their thyroid completely removed for thyroid cancer, but did not get any other procedures done to the thyroid such as radioactive iodine. The patients with the thyroid cancer who had the thyroid removed were then placed on T4 or levothyroxine therapy and their free T4, free T3, and TSH were measured. All the patients had a normal TSH and that was the criteria for being in the study. However, approximately 15% of the people had a low serum free T3 that was below the range previously established. An additional 5% of the patients had a free T4 above the range that was established. This shows that about 15% of the people do not convert the T4 to T3 properly. This was based on serum T3 levels and is a very good indication that these 15% of the people would need T3 in addition to T4 to get both levels in a normal range. This study suggested that measuring serum free T3 is quite helpful in patients that are treated with T4 for hypothyroidism, an evaluation that is not normally done. This paper did not measure reverse T3, which some Dr. Friedman also uses to determine that the T4 to T3 conversion does not occur and actually this paper suggested that the measurement of serum free T3 itself can be used to determine which patients need T4/T3 combination treatment.

Implications for Hypothyroidism Treatment

These 2 intriguing papers challenge the idea that all patients with hypothyroidism should be treated with T4. Dr. Friedman uses different thyroid medicines to treat patients with hypothyroidism including T4/T3 combinations, and desiccated thyroid that contains T4 and T3. Dr. Friedman interprets this data that the majority of hypothyroid patients do fine on T4 alone, include the patients he treats at Los Angeles County Department of Health Services. Approximately 15% of the population does need T4/T3 combination to have an optimal effect on the thyroid. Dr. Friedman feels these patients are the vocal minority who are not doing well on T4 treatment and would benefit from seeing a thyroid specialist like Dr. Friedman.

A Personalized Approach to Thyroid Health

For more information about Dr. Friedman’s practice or to schedule an appointment, go to www.goodhormonehealth.com.

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Supplements to Lower TPO Antibodies

January 16, 2025TfriedmanUncategorized
Supplements to Lower TPO Antibodies

There are some supplements that can be used to lower the TPO antibody. Selenium at 200 mcg a day (can be purchased at Trader Joes or online) can lower the TPO antibody as can Myo-Inositol plus from Omnibiotics, 2000 mg/50 mg once a day that can be purchased on Amazon. These supplements are helpful in those with a positive TPO antibody and a high normal or slightly elevated TSH, in patients who don’t want to take thyroid medicine. They are probably not helpful in those with a high TSH who definitely need thyroid medicine.

For more information on Dr. Friedman’s endocrinology practice, please go to www.goodhormonehealth.com.

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Anti-Thyroglobulin Antibodies and Hashimoto’s

January 14, 2025TfriedmanUncategorized
Anti-Thyroglobulin Antibodies and Hashimoto’s

There is some confusion about the role of anti-thyroglobulin antibodies in diagnosing Hashimoto’s. A large study using a national database called the NHANES database showed that only the TPO antibodies correlated with hypothyroidism and not anti-thyroglobulin antibodies.

The confusion seems to come that before the TPO antibody was identified, doctors used a test called an anti-microsomal antibody that was not as specific for Hashimoto’s as the TPO antibody. When that was the only test available for Hashimoto’s, an anti-thyroglobulin antibody was helpful because it could be used in complement with the anti-microsomal antibody to diagnose Hashimoto’s. However, now that the TPO antibody is standardized and is a very sensitive and specific test for Hashimoto’s hypothyroidism, there is no reason to get a anti-thyroglobulin antibody unless the person has thyroid cancer, in which it is a useful test.

For more information on Dr. Friedman’s endocrinology practice, please go to www.goodhormonehealth.com.

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Do I Need a Thyroidectomy After a Cancer Diagnosis? | Good Hormone Health

November 22, 2024TfriedmanUncategorized
Do I Need a Thyroidectomy After a Cancer Diagnosis? | Good Hormone Health

Thyroid Cancer

Thyroid cancer is quite common but very few people die from it or have a shortened lifespan because of it. In other words, don’t worry. Many people have a thyroid nodule found in their neck area. Sometimes you the patient notices a lump, sometimes the doctor finds it, and sometimes (especially more recently) it shows up on other studies such as when CT scans or MRIs are done.

Thyroid Function Tests If You Have A Thyroid Nodule

If a thyroid nodule is found, the first thing you should do is have your doctor determine your thyroid hormone status by measuring thyroid function tests, especially a TSH level. If you are hyperthyroid and have a suppressed TSH, the nodule could be what is called a hot nodule, in that it makes too much thyroid hormone, which can often be treated with either medicines or radioactive iodine. Hypothyroidism in which the TSH is high, may be part of a Hashimoto gland. If your TSH is high, you should get a TPO antibody measured, and you could be treated with thyroid medicines for it. However, most commonly, you are what is called euthyroid or have normal thyroid tests. In that case, the next step is to have a thyroid ultrasound done.

Thyroid Ultrasound

The thyroid ultrasound is crucial to determine who needs to get a thyroid biopsy and who can just watch their nodule. In addition to the maximal size of the thyroid nodule, the ultrasound should state different characteristics of the nodule including echogenicity (lumpiness) and whether the nodule is solid or cystic or a mixture. It will also describe the shape of the nodule.

Key Characteristics Assessed in Thyroid Ultrasound

The radiologist then gives a score called a TI- RADS which goes from 1 (looks very benign) to 5 (looks like it might be cancer). If the TI-RADS score is 3 and the nodule is bigger than 2.5 centimeter, or the score is 4 and the nodule is bigger than 1.5 centimeter or the or the score is 5 and the nodule is bigger than 1 centimeter, then Dr. Friedman would recommend a fine-needle aspirate (also called a biopsy).

If the TI-RADS score is less than these cut-offs, the nodule can be followed, usually with an ultrasound in a year. Thus, all patients with a thyroid nodule should get an ultrasound that helps determine the next course. Thyroid nodules with a higher TI-RADS score are more likely to be malignant, and in those cases the patient may need to get the total thyroid removed. Also, the ultrasounds look at lymph nodes, and if there are lymph nodes present, that would be more of a concern and more of an indication for a total thyroidectomy at the time of surgery.

Thyroid Biopsy

If the ultrasound suggests a biopsy, it should be done by a specialist who has many years of experience doing thyroid biopsies (Dr. Friedman does not do this procedure). The person who does the biopsy is often a radiologist, endocrinologist, or pathologist, and they put some numbing medicine on you before putting a needle into the nodule. The biopsy is done while you are lying down. Often, they put the needle in several times to get multiple samples to make sure they get tissue from the thyroid nodule. This sample gets sent off to the laboratory, where they determine whether it is cancer, possible cancer or not.

Types and Treatment for Different Types of Thyroid Cancer

There are several different types of thyroid cancer. The most common one by far is called papillary thyroid carcinoma, which occurs in at least 90% of the cases. The next most common is called follicular carcinoma, and then rarely it could be medullary carcinoma or anaplastic carcinoma, or thyroid lymphomas.

Diagnosing Thyroid Cancer

The pathologist will easily be able to tell about papillary thyroid carcinoma, anaplastic thyroid cancer, lymphomas, and medullary carcinoma. However, in terms of some papillary thyroid carcinomas and most follicular carcinomas (see below), sometimes it comes back clearly cancer, sometimes it comes back clearly non-cancer, sometimes it comes back not enough tissue to make a determination. If it comes back thyroid carcinoma, it depends on the size of the nodule and whether lymph nodes are involved.

When Surgery Is Not Needed

If the nodule is smaller than a centimeter, then surgery is not needed. Let me repeat that. Even if you have thyroid cancer, if your nodule is less than a centimeter, it is not recommended to undergo surgery. Some experts even suggest not removing it if it is less than 2 cm, but Dr. Friedman will probably recommend removal of those 1-2 cm. Of course, if you feel more comfortable having the thyroid nodule removed, you could have it removed. But in general, Dr. Friedman does not recommend surgery for these small thyroid carcinomas because they are very unlikely to affect people’s life.

Treatment for Nodules Between 1 and 3 cm

If the thyroid nodule is between 1 and 3 cm, and there are no lymph nodes involved, then Dr. Friedman usually recommends just having that half of the thyroid gland removed, which is called a hemithyroidectomy. This allows you to preserve thyroid function, and you will usually not need to take thyroid medicine. If the nodule is greater than 3 cm, a total thyroidectomy is usually recommended.

The Importance of Ultrasound in Treatment Decisions

Dr. Friedman also recommends that the ultrasound look carefully to see if there are any lymph nodes. If there are lymph nodes, then most likely a total thyroidectomy is needed, but if there are no lymph nodes and the nodule is between 1 and 3 cm, just taking out the site of the tumor is the recommended procedure.

Follicular Lesions

The problem that often occurs is that follicular thyroid cancers are very hard to tell on biopsy if they are cancer or not. It is rarely determined that it is follicular cancer. They often come back as follicular tumors that look like cancer, and that it would be recommended that the thyroid be removed even though there is only about a 30% chance they are malignant. There is also a category that is quite common, called follicular lesion of unknown significance (FLUS); these are most likely benign and often occur in thyroid glands that have Hashimoto’s. If this pathology comes back, then Dr. Friedman recommends checking the TPO antibody, and if the TPO antibody is positive, then could just watch it and repeat the biopsy in a year. These lesions can also be sent off for molecular testing. The patients who have smaller follicular lesion could also get a hemithyroidectomy (half your thyroid removed).

Total vs Partial Thyroidectomy

Although many other doctors recommend a total thyroidectomy for the papillary thyroid carcinomas and the follicular carcinomas, Dr. Friedman does only recommend taking out half of your thyroid. Usually, people who have the total thyroid removed have more hypothyroid symptoms than people who have hypothyroidism from Hashimoto. For these reasons, Dr. Friedman likes to keep the thyroid in place.

Balance

Dr. Friedman wants to balance the downsides of having aggressive surgery but also wants to make sure the thyroid cancer does not give people problems and spread. It is very rare for thyroid cancers to spread, but a balance between doing the right amount of surgery is what is needed in these cases. In general, thyroid experts including Dr. Friedman are recommending less aggressive treatments than 20 years ago.

If you are have thyroid cancer and want to take advantage of Dr. Friedman’s expertise in this area, please do not hesitate to make an appointment by visiting his website at goodhormonehealth.com.

*Photo by Ed Uthman

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Using rT3 to Assess Hypothyroidism

November 20, 2024TfriedmanUncategorized
Using rT3 to Assess Hypothyroidism

Controversy Surrounding Reverse T3 (rT3) Measurement

There is polarization about whether reverse T3 (rT3) should be measured to assess hypothyroidism with most traditional Endocrinologists being against its measurement and functional medicine doctors being in favor of it. The normal thyroid gland secretes T4 (an inactive precursor), T3 (the active hormone), and reverse T3, a biologically inactive form of T3 that may block T3 from binding to the thyroid hormone receptor. Most of the circulating T3 is derived from 5′-deiodination of circulating T4 in the peripheral tissues by type 1 deiodinase. Deiodination of T4 can occur at the outer ring (5′- deiodination), producing T3 (3,5,3′-triiodothyronine), or at the inner ring, producing reverse T3 (3,3,5′-triiodothyronine) by type 3 deiodinase. Type 2 deiodinase in the pituitary also converts T4 to T3 and is regulated differently from type 1 deiodinase.

rT3 and Sick Euthyroid Syndrome

Many years ago, endocrinologists realized that in severe illnesses, type 3 deiodinase increases and rT3 is often high and T3 is often low. Endocrinologists termed this “sick euthyroid syndrome” and noted that it was common in many types of chronic illnesses, especially in patients hospitalized in intensive care units. It was usually recommended that these patients not be treated with thyroid hormone and in most cases, the elevated rT3 resolved when the patients’ health returned.

Functional Medicine Perspective on rT3

However, more recently, more alternative doctors, including doctors who used to be known as antiaging doctors and now are called functional medicine doctors, have made quite an issue about rT3. They argue somewhat appropriately that high rT3 is bad and can block T3 from binding to the thyroid hormone receptor. They also state that rT3 can go up in various conditions including systemic illness, stress, inflammation, chronic pain, dieting, weight gain, and depression. They often quote articles showing that these diseases are correlated with a high rT3, but do not necessarily show that the rT3 plays a significant role in the disease. These functional medicine doctors rely extremely heavily on rT3 to treat patients that may have no other laboratory findings of hypothyroidism and often prescribe them T3-only preparations to try to lower the rT3. They have not published on whether this is effective or not, and may treat a person with completely normal thyroid function tests and put him on T3 to try to lower the rT3. They often use a high rT3:T3 ratio as further indication to treat these patients.

Concerns about inappropriate T3 treatment in patients without thyroid disease

Dr. Friedman has seen many of these patients put on thyroid hormone, especially T3, inappropriately. T3 does not penetrate the brain well, not nearly as well as T4 does, and these patients often suffer from hyperthyroidism systemically and hypothyroidism in their brain. Dr. Friedman also believes that a healthy thyroid works best on its own and prescribing exogenous thyroid hormones to a patient with a normal thyroid gland, causes the gland to stop making its own hormones. Sometimes it is very hard for the patient to stop thyroid hormones, especially if given in high enough dose or for a long period of time. Therefore, he is quite cautious about who he puts on thyroid medicine and who he does not.

Dr. Friedman’s Study on rT3 Measurement in Patients on thyroid hormone treatment (submitted to PLOS One)

Dr. Friedman wanted to know if rT3 was indeed higher in patients on L-T4 preparations and after achieving IRB approval, decided to measure rT3 in 976 consecutive patients who came to see him with potential thyroid problems. All of these had signs and symptoms of hypothyroidism, and many of them were already treated with different thyroid preparations. He used the upper limit of normal for rT3 at either Quest or Labcorp, which is 24 ng/dL. He did not calculate any type of ratios. Dr. Friedman and colleagues found that the number of patients with rT3 levels above normal range varied significantly with the type of thyroid hormone replacement.  The highest rate of an elevated rT3 was 20.9% (29/139) in patients taking T4 alone. 9% (31/345) of patients not taking thyroid hormone replacement had elevated rT3 values. In contrast, only 3.5% (8/226) of patients taking desiccated thyroid hormone with synthetic thyroid had above normal rT3 values, compared to 12% (10/83) of patients taking a T3-T4 combination and 17.4% (24/138) of patients taking desiccated thyroid-T4 combination. Patients on all types of L-T4 treatment had higher rT3 levels than those not on L-T4 treatment (p < 0.00001) and a higher percent of rT3 levels above the cutoff of 24.1 ng/dL (p < 0.00001). Linear regression analysis showed rT3 levels correlated with free T4 and free T3 levels and inversely with log TSH levels.

In conclusion, this study found elevated rT3 levels in patients with symptoms of fatigue on various thyroid hormone replacements with highest levels in L-T4 alone replacement and the lowest levels in those on preparations that contain L-T3. Further studies are needed to understand the implications of elevated rT3 values in patients both on and off thyroid hormone replacement and whether its measurement will be useful in clinical practice to guide thyroid hormone replacement.

Recommendations for rT3 Testing

Dr. Friedman concluded from his study that measuring rT3 is helpful in patients already on thyroid treatments with preparations containing T4 having higher rT3 levels. Most but not all patients on no thyroid treatment have normal rT3, levels so its less helpful in those patients. Patients that have an elevated rT3 on thyroid treatment with either T4 alone or T4 plus desiccated thyroid may benefit from decreasing the amount of T4 given and increasing the amount of T3 or switching to desiccated thyroid extract (DTE).

The concept is in those patients on levothyroxine (L-T4, Synthroid) with a high rT3 you can add on T3 or use DTE that has T3 to “kick out the rT3.” This would lead to improved thyroid function and symptom improvement.

The area of rT3 is clearly an interesting area, and there is a clear division between endocrinologists who do not measure all and the functional doctors who measure it in almost everybody and treat almost everybody for it. Dr. Friedman is hoping that his peer-reviewed article on measuring rT3 is published, there will be more clarity on rT3 measurement.

Ongoing Research and Expert Care

Dr. Friedman is an expert at putting the right patients on the right thyroid hormone. For more information about Dr. Friedman’s practice or to schedule an appointment, go to www.goodhormonehealth.com

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Hypothyroidism Diagnosis

November 15, 2024TfriedmanPosts
Hypothyroidism Diagnosis

Introduction to Hypothyroidism

Hypothyroidism is a relatively common disorder. It affects more women then men, but I happen to be one of the men who does have it. Symptoms of hypothyroidism include fatigue, gradual weight gain, constipation, muscle aches, joint pain, feeling cold, menstrual irregularities, weakness, hair loss, dry, cold skin and slow reaction time. Many patients will have a goiter (enlarged thyroid). Although it has received much discussion, I believe low body temperature is not a reliable sign of hypothyroidism.

Causes of Hypothyroidism

The incidence of hypothyroidism increases with increasing age. In other words, the older we get, the more likely a thyroid deficiency will show up. The most common cause of primary hypothyroidism (hypothyroidism originating in the thyroid gland itself), is Hashimoto’s Thyroiditis. Hashimoto’s is an autoimmune condition. The body’s own antibodies attack the thyroid gland and destroy it, leading to hypothyroidism. Hashimoto’s Thyroiditis may be a manifestation of multiple autoimmune syndromes and may occur in families. Hypothyroidism can also be due to a pituitary problem (central hypothyroidism).

The Importance of Diagnosis

Diagnosing all types of hypothyroidism is important, because treatment with thyroid hormone will improve symptoms in patients with hypothyroidism, but is unlikely to help those who do not have hypothyroidism. In primary hypothyroidism, the thyroid gland, located in the neck, is less able to produce the thyroid hormones, T4 and T3. The pituitary gland, located in the head, responds to this deficiency by secreting more TSH. Thus, in more mild cases of primary hypothyroidism, T4 and T3 levels are normal, but the TSH is high. In more severe cases, T4 and T3 levels drop. Although the normal range for TSH is often between 0.5 and 5 mU/mL, values at the high end of the normal range may be abnormal. T3 is the more bioactive hormone compared to T4, but T4 is more stable in the circulation.

My approach to diagnosing hypothyroidism is to start with a careful history and physical. Then an Endocrinologist should perform a hands-on thyroid examination to determine if the patient has a goiter. Blood TSH, free T4, free T3 and anti-TPO antibodies should be tested. Patients with an enlarged thyroid and/or a positive anti-TPO antibody test AND a TSH> 4.0 mU/mL should be considered to have primary hypothyroidism. Patients without an enlarged thyroid and without a positive anti-TPO antibody test but WITH a TSH> 7.5 mU/mL should also be considered to have primary hypothyroidism. Patients with a free T4 of < 0.9 ng/dL and a TSH< 1.0 mU/mL are likely to have central hypothyroidism. Patients with symptoms of hypothyroidism but who do not meet these criterion should be watched and retested in 6 months.

Hypothyroidism Treatment

Once hypothyroidism is diagnosed, there are many treatment options, including synthetic Lthyroxine (T4) preparations (Synthroid, Levoxyl and Unithroid), synthetic L-triiodothyronine (T3) preparations (Cytomel), synthetic T4/T3 combinations (Thyrolar) and dessicated thyroid preparations (Armour, Naturethroid, Bio-Throid, and Westhroid). All of the L-thyroxine preparations contain the same active ingredient, but contain different fillers and have different quality control. Until recently, Synthroid did not have FDA approval, but now all L-thyroxine preparations have FDA approval. Thyrolar and the dessicated thyroid preparations probably have a higher T3/T4 ratio than desirable and thus, I often give a lower amounts of these preparations supplemented with T4.

Most Endocrinologists use L-thyroxine preparations for the initial treatment of all forms of hypothyroidism. Although the use of L-thyroxine (T4) compared to L-triiodothyronine (T3) may be surprising as T3 is the more bioactive thyroid hormone, T4 is most frequently used. This is because tissues convert T4 to T3 to maintain physiologic levels of the T3. Thus, administration of T4 results in bioavailable T3 and T4. As T4 is more stable than T3, T4 therapy gives even blood levels, while T3 therapy leads to high levels after taking the medicine and low levels before the next dose. Armour thyroid is the least expensive preparation. Because Armour thyroid comes form pig thyroids, some Endocrinologists feel that there is high pill to pill variability, but this is unlikely to be true.

Personalized Treatment Considerations

A recent study published in New England Journal of Medicine in 1999 suggested that brain T4 to T3 conversion may be impaired in some patients and that a select group of patients should be treated with both T4 and T3. Other studies published in Journal of Clinical Endocrinology and Metabolism in 2003 suggested that addition of T3 to T4 treatment is not needed for most patients with primary hypothyroidism. I recommend that most patients be started on a T4 preparation, which improves symptoms in the large majority of the patients. I have found that most patients prefer Levoxyl or Unithroid to Synthroid, but this varies with each patient. After initial treatment with T4, I adjust their T4 dose until their TSH is between 0.5 and 2 mU/mL. If they remain symptomatic despite an optimized TSH, then low doses of T3 given two or three times a day can be added cautiously to T4. If patients start with a low blood free T3 level, then I am more inclined to treat them with T4 plus T3. On T4 plus T3 therapy, I use blood tests to make sure the free T4 and free T3 are in the upper-normal range. The TSH value is usually suppressed on combination treatment.

A percentage of patients will have symptomatic improvement on T4 plus T3 therapy. For those that do not improve, I occasionally recommend treatment with dessicated thyroid preparations, usually Armour, plus synthetic T4. This combination is needed as dessicated thyroid preparations have a higher T3/T4 ratio than desirable and need to be supplemented with synthetic T4 to achieve normal ranges of both hormones. Again, I aim for a free T4 and free T3 in the upper-normal range.

A Personal Case Study

Patients with central hypothyroidism can be treated with any of the preparations available for patients with primary hypothyroidism. The difference is that treatment needs to be monitored by aiming for a free T4 and free T3 in the upper-normal range, as TSH is suppressed with proper treatment. Patients with both central and primary hypothyroidism also needed to be treated by aiming for a free T4 and free T3 in the upper-normal range.

I was diagnosed with primary hypothyroidism in February 2003. An Endocrinologist performed an examination of my thyroid gland and I was found to have a goiter. My blood values showed a TSH of 8 mU/mL and strongly positive anti-TPO antibodies. I have a strong family history of Hashimoto’s Thyroiditis but I was lucky to be fairly asymptomatic prior to treatment. I am now on 150 mg a day of Levoxyl, have a TSH of 1.9 mU/mL and feel great. I have lost a few pounds on T4 therapy and my cholesterol profile has improved.

Contact Dr. Friedman for a Consultation

For more information about Dr. Friedman’s Endocrinology clinic, visit his website at www.goodhormonehealth.com. To schedule an appointment with Dr. Friedman, please email Kimberly at appointments@goodhormonehealth.com.

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The 15% Rule of Who Should Get T4/T3 Combination

July 7, 2024TfriedmanUncategorized
The 15% Rule of Who Should Get T4/T3 Combination

Understanding Thyroid Hormones: T4 and T3

The thyroid makes two hormones, T4 which has a long half life meaning it can be given once a day. T4 gets converted to T3 which is the active form of the hormone and has a short-half life, meaning it has to be given frequently. Most patient with hypothyroidism are treated with levothyroxine, which is T4. There are many brands of levothyroxine that include Synthroid, Unithroid, and Levoxyl.

Challenges with T4-Only Therapy

However, two very important recent articles suggested that about 15% of patients with hypothyroidism do not convert T4 to T3 properly and should be on a T4/T3 combination or on desiccated thyroid that contains T4 and T3. I wish to highlight both of these papers as they are very interesting and important studies.

Study on T4 to T3 Conversion: The UK Research

One study came from the United Kingdom that looked at the prevalence of the gene that converts the T4 to T3. This is called the type 2 deiodinase. In this study, 15% of the population had an alteration in the gene that converts T4 to T3, the alteration is called a polymorphism. This polymorphism means the DNA is changed so that this enzyme works less effectively. The patients with this polymorphism required higher T4 dosing and had more psychological problems than those that did not have the deiodinase polymorphism. They did not examine whether these patient would benefit from T4/T3 combination and also did not actually measure the enzyme, they only looked at the gene coding for this enzyme.

Italian Study on Free T4 and T3 Levels

Another very intriguing article came out in Italy that initially examined patients that had a thyroid nodule but were not on a thyroid medicine and did not have any other problems with their thyroid. Examining several thousand of these healthy patients, they were able to establish normal values for free T4, free T3, and TSH in this Italian population. Once these normal values were obtained, the researchers then took patients that had their thyroid completely removed for thyroid cancer, but did not get any other procedures done to the thyroid such as radioactive iodine. The patients with the thyroid cancer who had the thyroid removed were then placed on T4 or levothyroxine therapy and their free T4, free T3, and TSH were measured. All the patients had a normal TSH and that was the criteria for being in the study. However, approximately 15% of the people had a low serum free T3 that was below the range previously established. An additional 5% of the patients had a free T4 above the range that was established. This shows that about 15% of the people do not convert the T4 to T3 properly. This was based on serum T3 levels and is a very good indication that these 15% of the people would need T3 in addition to T4 to get both levels in a normal range. This study suggested that measuring serum free T3 is quite helpful in patients that are treated with T4 for hypothyroidism, an evaluation that is not normally done. This paper did not measure reverse T3, which some alternative doctors use to determine that the T4 to T3 conversion does not occur and actually this paper suggested that the measurement of serum free T3 itself can be used to determine which patients need T4/T3 combination treatment.

Implications for Hypothyroidism Treatment

These 2 intriguing papers challenge the idea that all patients with hypothyroidism should be treated with T4. Dr. Friedman uses different thyroid medicines to treat patients with hypothyroidism including T4/T3 combinations, and desiccated thyroid that contains T4 and T3. Dr. Friedman interprets this data that the majority of hypothyroid patients do fine on T4 alone including himself, who takes only T4. Approximately 15% of the population does need T4/T3 combination to have an optimal effect on the thyroid. Dr. Friedman feels these patients are the vocal minority who are not doing well on T4 treatment and would benefit from seeing a thyroid specialist like Dr. Friedman.

A Personalized Approach to Thyroid Health

For more information about Dr. Friedman’s practice or to schedule an appointment, go to www.goodhormonehealth.com.

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Graves’ Disease vs Hyperthyroidism

January 9, 2024TfriedmanPosts
Graves’ Disease vs Hyperthyroidism

Introduction to Graves’ Disease

Dr. Friedman is one of the world’s experts on treating Graves’ disease.  Graves’ disease is a type of hyperthyroidism that is autoimmune in nature.  

Understanding Hyperthyroidism in Graves’ Disease

The thyroid gland is stimulated by the same antibodies that can lead to hypothyroidism in Hashimoto’s hypothyroidism.  In Graves’ disease, the thyroid gland is enlarged and makes excess thyroid hormone, especially T3 but also T4.  The TSH is suppressed.  

Symptoms of Graves’ Disease

The symptoms of Graves’ disease and hyperthyroidism are the similar, and they include palpitations and rapid heart beat, sweating, shakiness, diarrhea or loose stool, weight loss, and increased appetite.

Other Causes of Hyperthyroidism

There are different causes of hyperthyroidism besides Graves’ disease, which is the most common.  A patient with hyperthyroidism can also have a single hot nodule, a toxic multinodular goiter, thyroiditis, or is taking too much thyroid medicine.  

Distinguishing Graves’ Disease

However, in Graves’ disease, the gland is uniformly enlarged, while in a single nodule, an ultrasound or palpation can reveal the single nodule, and in toxic multinodular goiter, there are multiple nodules present.  In thyroiditis, the gland is usually very tender.  Graves’ disease is also associated with Graves’ exophthalmos, where the eyes are bulging, and occasionally can be associated with Graves’ dermopathy, which is a skin change usually in the shin area.

It is important to distinguish between Graves’ disease and other causes of hyperthyroidism as the treatment and prognosis may be different.

Contact Dr. Friedman Today!

For more information on Graves’ disease, please look at Dr. Friedman’s website, goodhormonehealth.com.

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