Why some people can’t tolerate T3 and natural desiccated thyroid medications

Why some people can't tolerate T3 and natural desiccated thyroid medications

You’ve read about T3 and natural desiccated thyroid medication options for hypothyroidism and you’ve finally found an open-minded thyroid doctor to prescribe it but it’s NOT WORKING. Now what?

Written by David Borenstein, MD

Time and time again thyroid patients visit my office feeling sick and tired for years or even decades. The vast majority have only heard about T4-only levothyroxine medications like Synthroid. These medications are the only treatment most conventional doctors will consider but many patients fail to be well.

Then there are the well informed thyroid patients that have read about the benefits of combining synthetic T3 and synthetic T4 levothyroxine medications or taking natural desiccated thyroid instead but struggle to find doctors open to prescribing it. Once the right type of thyroid medication and dosage is found for that patient, the vast majority of their symptoms disappear and the remaining ones diminish. Their lives can change just like that.

Then there are the patients that have finally found doctors to try T3 and/or natural desiccated thyroid but it’s just not working. They either find no change at all or they feel worse including experiencing heart palpitations. Their doctors will conclude that T3 and NDT are just not for them, but the patient is left without a solution.

Treating the thyroid is the most complex condition that I have found in my practice. Each patient is bio-individual. There is no one thyroid medication or dosage that will be right for every person. There just isn’t. Finding what is right for YOU is the key and it takes careful trial and error with a knowledgable doctor.

Here are some key findings that I’ve discovered over my 15 years working with thyroid patients.

Adrenal Fatigue

Adrenal fatigue may be exposed during thyroid hormone treatment, especialy while taking synthetic T3 along with T4 or natural desiccated thyroid NDT medication or even T3 alone, as T3 is more potent than T4. I always adress the adrenals before starting my patients on any T3 therapy. I check morning AM cortisol at a minimum with salivary or blood testing but it is ideal to check cortisol levels at different points over the day. If the cortisol levels are abnormal then I recommend a blend of adaptogenic herbs and high dose Vitamin C, or adrenal extracts in some cases. The vast majority of supplements that I use are from the brand Ortho Molecular. I also recommend improving sleep, reducing coffee intake, starting a gluten and dairy free diet, and implementing relaxation techniques.

Iron Problems

I find that low iron leads to poor T4 to T3 conversion which is a common problem for hypothyroid people in particular because of lower stomach acid and chronic inflammation. Heavy periods that can come with hypothyroidism in women can cause iron deficiency. The solution is iron supplements (take with Vitamin C to increase absorption and avoid constipation) or even iron patches that are now available. I always run comprehensive iron lab testing before recommending iron supplements and retest over the course of supplementation to avoid iron overload. I advise my patients to take iron supplements including multivitamins with iron 3 to 4 hours apart from thyroid medication.

Type of T3 or NDT

There is a significant difference between fast and slow release T3. Fast release preparations like the brand Cytomel can cause more symptoms, such as palpitations and anxiety. I find my younger patients tolerate fast release T3 much better. When I prescribe fast release Cytomel, I advise my patients not to take their daily dose all at once but rather divide their daily dose into 2 or 3 smaller doses throughout the day. In older patients, I usually recommend sustained release T3 (available through compound pharmacies) to reduce risk of side effects like palpitations. Slow release T3 has been particularly helpful for my patients with high Reverse T3. Instead of the body converting inactive T4 to the active T3 hormone needed by the cells, the body can instead convert it to inactive Reverse T3. The are many reasons this can happen including calorie-restricting diets, chronic illness, inflammation, infections, gut imbalances, stress, and even certain prescription medications. However even with slow release there may be problems if the person has digestion issues. There is no one solution that is right for everyone. Make sure the compound pharmacy is experienced in sustained release T3 compounding because many are not.

For each brand of thyroid medication, there are different fillers, binding agents, dyes and other ingredients that will vary. Our bodies will vary in terms of the sensitivities we experience to the different brands. A patient will visit my office and ask to be put on Armour because her friend is doing brilliantly on it. Then she will try Armour and may not respond well to it (the reactions will vary too) and find that another brand like Nature-throid is better for her.

Thyroid Medication Shortage

Over the years there have been shortages of one or another thyroid medication brand, including the recent Nature-throid and WP thyroid shortage. Doctors and patients have had to scramble to find alternatives. Reformulations of brands have happened too leaving patients feeling unwell on the new versions. Now what? Finding an alternative can be tricky as our bodies are all different. In cases where my patient reacts poorly to every brand we try, I usuallly compound the NDT for these people and in most cases they feel better. Compounding pharmacies can custom make formulations and remove ingredients to which the person reacts poorly.

Dosage of T3 or NDT

I find most conventional doctors are not familiar with T3 and NDT thyroid medication options and actually use very little. I have many patients come to my office that report finding no improvement on T3 and NDT and I find that the problem is the dosage was far too low. In the case of patients with heart palpitations, doctors may put them on too high a dosage to start. I start at a moderate dose and increase incrementally over time until I find the ideal dosage for that particular patient.

Nutrient Deficiencies

I find nutrient deficiencies common in thyroid patients and comprehensive lab testing can be invaluable including testing for Vitamin D, Vitamin B12, Iodine, Selenium, Zinc, and Magnesium. In cases where patients experience palpitations with low dose T3, I find supplementing with magnesium 500 mg a day helpful. I prefer Ortho Molecular Reacted Magnesium. It is gentle, gut “friendly”and does not cause diarrhea that often accompanies other forms of magnesium.

Hashimoto’s Thyroiditis

Most of my patients with Hashimoto’s do well on T3 and NDT. However, a small subset of patients will feel worse on NDT. Their symptoms worsen, TSH and antibodies all increase. Hashimoto’s is an autoimmune disease where the immune system erroneously attacks the thyroid gland. Given that NDT is made from pig thyroid which is biologically similar to human thyroid, it is not hard to imagine why this may happen. I use a combination of synthetic T4 and synthetic T3 in these cases.

Another word on Hashimoto’s, I’ve found low-dose naltrexone (LDN) treatment very helpful. I also find LDN great for fibromyalgia. Before I use LDN for Hashimoto’s, I work on diet, blood sugar imbalance, digestion, inflammation, infections, and toxicity. After we’ve tried everything, then we consider LDN.

Success Stories

I had a 20 something female with bad palpitations on Cytomel. I held her Cytomel for a week, gave her adrenal support, then put her on slow release T3 by a compounding pharmacy. We also added magnesium supplementation at 500 mg at bedtime. It took 2-3 weeks but she then was able to tolerate any dose increase to get her to optimal.
Here is a second case that I am working on right now, a 46 year old hypothyroid male with severe Crohn’s disease, an inflammatory bowel disease. I gave him stem celll treatment and in one week he had increased energy, less bloating, and more solid bowel movements. I did not put him initially on slow release T3 because I was worried about his digestive issues and thought there would be absorption issues. I decided to put him on fast release Cytomel and try that first but his symptoms came back! So now I use slow release t3 and he is doing great. It’s not what I initially expected but with trial and error we found the right treatment for him.

It Takes Time

For the vast majority of thyroid patients there are multiple health conditions from adrenal issues to nutrient deficiencies to individual sensitivities going on. Don’t expect a quick fix in one or two appointments. It is well worth the time it takes to work with a knowledgable doctor to find the right thyroid treatment for you.

About David Borenstein, MD

Dr. David Borenstein is the founder of Manhattan Integrative Medicine and the New York Stem Cell Treatment Center. He obtained his medical degree from the Technion Faculty of Medicine in Haifa, Israel and completed his internship at Staten Island University Hospital. Dr. Borenstein is regularly featured by thyroid expert Mary Shomon at VeryWell Health. He serves as medical advisor for the film Sick to Death! created to support changing medical practices around thyroid disease. He has been published in the European Journal of Ultrasound and has been the Chief Investigator on a research project on Spinal Cord Injuries.

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About Dana Trentini

Dana Trentini founded Hypothyroid Mom October 2012 in memory of the unborn baby she lost to hypothyroidism. This is for informational purposes only and should not be considered a substitute for consulting your physician regarding medical advice pertaining to your health. Hypothyroid Mom includes affiliate links including the Amazon Services LLC Associates Program. Connect with Dana on Google+


  1. I came across this post in my recent research on hypothyroidism. In the past year, I’ve slowly had my NatureThroid increased from 1.5 gr to 3 gr and still having low FT3 and low FT4. I switched physicians recently and one thing we are doing is adding Cytomel 2x/day in incremental, small doses to my NatureThroid. It’s starting to help me, but it’s slow! She did more extensive bloodwork and we discovered I DON’T have high reverse T3 and NOPE, I don’t have thyroid antibodies that are high, so not likely Hashimoto’s. Over the summer, I had a thyroid ultrasound and it came back normal. So, it’s just wait and see. I keep wondering if something is up with the NatureThroid formula, due to their shortages. I also do wonder about my ability to tolerate the NDT type of thyroid medications. I’ve been on them for 20+ years, but interesting that it’s the synthetic T3 that is helping me to feel better, but added with the NatureThroid. I hope to reduce my NatureThroid. I’m super petite, 105 pounds at 5’2 and marvel at taking such a high dose, haha! One thing to mention is that checking a woman’s hormones using a dried urine test method such as DUTCH testing (not saliva one since it won’t show metabolites!) is important! We discovered I have been estrogen dominant, which is not something you’d expect from just looking at me, a lean person. Estrogen dominance can suppress the thyroid and it’s my understanding that TSH especially can be suppressed. My new physician changed my progesterone bioidentical cream dose, delivery method and application site. So far, I’m feeling way better. Hormone balancing is such a delicate thing. I agree re: comments about healing the gut and iron aspects. I do feel though that eating a vegan, whole food plant-based diet has helped me and my thyroid more than any other medical intervention. I reduced my inflammation significantly, which I believe put my Hashimoto’s in remission, along with creating a negative ANA in my case. I had stellar levels of B12, D, selenium, iron, magnesium, and iodine, even though I eat plants (I do take B12 supplements). I’m having to address a zinc deficiency though with supplements. One thing to also look at is copper levels too. If they are too high, it can cause issues. Thanks for letting me chime in.

  2. I was taking Armour Thyroid (15 mg) for three years with no problems, however, the following year I began having throat and chest pains. Has anyone else had this problem and if so what did you do to alleviate the problem. I don’t understand why I tolerated it well for three full years and now I can no longer.

  3. I am 43 was recently diagnosed with hypothyroidism. My Dr. prescribed Cytomel to begin with and I started on a generic brand. I started sleeping well, loosing weight, and regaining cognitive abilities that had greatly deteriorated. It felt like a miracle! One day, I was doing a simple crafting project with my daughter and could not follow simple instructions. I checked my script and noticed the generic had been changed on a recent refill. Not only was my weight increasing but I developed a nasty itch on one leg. I called the pharmacy and switched the medication for the first generic brand. Things very slowly improved. I spoke to many people including doctors and pharmacists about my issues with the generics and found that many of them suggest brand name only. I spent the big bucks and began Cytomel. For the last month I have not been sleeping well. I am up multiple times and my husband reports that even when I am asleep, I kick,scream, talk, toss and turn. Yet again, I just switched back to the first generic. I do not feel my Thyroid is regulated correctly yet but I do feel much better. This is a crazy ride getting this figured out!

  4. Hi JoAnn. If you have symptoms of stomach acid issues, then do research Hydrochloric Acid and Pepsin.Symptoms of low acid are the same as high acid and I believe, especially as we get older, that our stomach acid is likely to be too little rather than too much, thus needing supplementing.

  5. Christine says:

    Unfortunately my journey wasn’t a simple one. I had to resolve working and living in a place with toxic mold/mycotoxin/biotoxin, endogenous retroviruses and environmental pesticides too. These issues are more prevalent and causative than many people and professionals know or admit. Learn about these, see if it applies then do what you need to do to live. We breath a lot more often than we eat so it’s not only about food and supplements. Air quality, water quality and light quality….and amounts for all of them matter.

  6. After years of trying Levoxyl/Armour, Armour only, Nature-Thryoid only, Levoxyl/Nature-Thryoid, Levoxyl only and Cytomel only…. my Doctor and I have never found my maintenance dose. Never. I tried LDN, it did absolutely nothing for me. In fact, if I take anything more than 1 grain of NDT, my weight EXPLODES. I gain on average 2.5 pounds every week until the meds are lowered back to 1 grain. I know its the T3 because I gained 23 pounds on Cytomel as well when I took that alone for several months. Yet, I’ve tried T4 only as well that that doesn’t work for me either. My symptoms are so extreme I can barely move some days. Some days I seem to have all 300 thyroid symptoms it seems like. I’ve taken every adrenal supplement there is, had MTHFR testing, you name it. Nothing has ever worked for me. Hypothyroidism has destroyed my life.

    • Have you ever tried an elimination diet? I have found a few additives make ‘hypo symptoms’ a lot worse – some completely floor me. Artificial sweeteners and acacia (gum arabic) are the main culprits along with alcohol. Tiny amounts make me feel ill e.g. drinks dispensed from a soda gun where other ‘diet’ drinks are also dispensed, so contaminated with artificial sweeteners. Also some meds have acacia in them so I have to always check the ingredients of everything including pain relief etc. Recently discovered mint candy I was eating also contained acacia – I was blaming new meds which I thought weren’t working. Really worth a try to find if something is making things worse.

    • Hi Katie. So sorry for your troubles. I was diagnosed with Hashi’s as well as Celiac and Type 1.5 diabetes at 45 yrs old. It took me 9 years to finally get what I needed. I guided my doctors to get proper lab work and we discovered that my body is not converting the T4 to T3 properly. My doctor had a combination T4/T3 made for me at a compounding pharmacy this past August. The results were astounding, like being reborn. No one should suffer for years like that, everyone is different too, keep trying. I also have had great success with a whole food, plant based diet (gluten/dairy/grain free as well).

  7. JoAnn Clarke says:

    I really appreciate your site and the valuable information shared among the many of us who have been “neglected” by medical professionals. I am perplexed however, on some conflicting info. I was diagnosed with Hashi’s at age 25 and prescribed Synthroid, Later while at my peak of health ( or at least feeling healthy & regularly exercising) was diagnosed with Rheumatoid Arthritis. ( my feet became seriously inflamed and I could barely walk) at age 42. I understand that those with Hasi’s as having a “low acid” gut but noticed a lot of information about taking baking soda to reduce inflammation. I am gluten free & dairy free. On Orencia weekly injections and taking Nature Troid plus many supplements. Your thoughts?

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