Tag Archives: T4

Endocrinologists Take a Backward Step in the Treatment of Hyperthyroidism


When I became an endocrinologist in 1981 I was truly excited about the field. At that time it seemed that the science of endocrinology was expanding rapidly and new discoveries were on the horizon particularly in regards to the way hormones effect the brain, mood and the immune system. Was I ever wrong! It’s thirty years later and none of those expectations were realized. In fact, I find that the field of endocrinology has barely budged since then and in some areas has actually lost ground.

Bringing on this round of pessimism on my part, is a recent “development” in the area of treatment for hyperthyroidism (over active thyroid). Ever since I was in training there have been two medicines, propylthiouracil (PTU) and methimazole (Tapazole), which are the mainstays of medical treatment for hyperthyroidism. Both medicines have been available since the 1940’s and show excellent efficacy and tolerability (and they are cheap!). Almost all endocrinologists I have met use these two drugs interchangeably although in pregnancy propylthyiouracil is favored due to rare birth defects in fetuses exposed to methimazole.

The “development” which I find so discouraging is the recent action by the FDA to place a very strict (black box) warning on the use of PTU due to the possible occurrence of a rare form of liver injury attributed to the drug. After almost 70 years of exemplary use, this has given rise to extensive debate in the endocrinology literature about how to restrict PTU use.

While it is true that methimazole is equally as effective as PTU to treat hyperthyroidism, I have personally seen numerous cases of fairly severe allergic reactions to methimazole. Fortunately it has been easy to continue medical treatment by simply switching to PTU. If we can’t use PTU freely then the only other options are surgical removal of the thyroid or eradication of the thyroid using radioactive iodine, neither of which is free of potentially adverse outcomes.

I have never encountered severe liver injury with PTU nor has any of the colleagues I have polled. It has to be very, very rare. This is obvious because it has taken 70 years to get around to recognizing it formally. Can we really call it progress that we now have one less simple option for treating hyperthyroidism, a common and relatively benign disease? Let me take my cynicism to the next level. I won’t be surprised if a major pharmaceutical company soon announces the development of a new drug for treating hyperthyroidism. If I’m right the new drug will add nothing of real value that wasn’t previously available but is many times more expensive then the drug it replaces.

So goes endocrinology into the new century, the stogy old lady of medicine.

Suzi’s Amazing Blood Pressure Response to Cytomel (t3)


Suzi has hypothyroidism and high blood pressure. She sends the following story describing how t3 treatment appeared to help normalize her blood pressure. This is the first time I have come across this effect and thought it would be helpful to share her story on the main blog. Does anyone else have a similar (or contradictory) experience?

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Hi Dr. Pepper,

I was diagnosed hypothyroid 2 years ago and given levothyroxine. On diagnosis I had lots of symptoms and my BP was 175/115 despite my whole family having low BP. After some months on T4 I did feel an improvement in a lot of ways and my BP got better. Then after a year, things started going wrong, as if my body didn’t like T4.

I tried reducing my dose of T4 back down to 75µg but went hypo. But each time I increased above 75µg my BP increased again, then on 112µg it became a serious problem, especially the diastolic. I still had fatigue, constipation, red eyes, swollen legs and so on.

About 3 weeks ago I started on 10µg T3 and reduced my T4 from 112 to 75µg and pretty much immediately felt clearer headed and more energy, the constipation went etc….. My BP has gone down by an average of 20, which I know because I check it regularly myself. I’m doing a 24-hour BP monitor this week too, because my doctor put me on Amlopidine 6 weeks ago after being shocked by the monitor results from then while on 112µg T4 (only took Amlopidine for 2 weeks after terrible side-effects incl. overwhelming fatigue and massively swollen legs).

So, it looks as though my body goes weird on T4 tablets when the dose is above 75µg, but if I stuck to that dose I’d be really hypothyroid. The T3 has changed my life completely!!

Now I’m wondering what the ideal balance T4 / T3 tablets would be? Is that possible to say or does it depend on each individual body and genetics? My typical BP now is around 120/ 95; it goes down after eating, and gets worse when I’m hungry or tired. The T3 reduced my BP so much more than the Amlopidine did, and on T3 I feel great whereas on Amlopidine I felt half dead. I’d like to get my BP back to before I got hypo, so that’d be 110/70.

All I need to do now is find my ideal dose of T4 and T3, could you possibly advise me on that? If I started 20µg T3 instead of 10µg, would you advise a reduction in T4 from 75µg? ( I’ll be doing a TSH, fT3 and fT4 test in about 5 weeks’ time, maybe I should wait till then?).

Thank you so much!

What You can Learn from Sarah’s Struggle With Hypothyroidism


Every so often I like to bring attention to someone who has struggled to get properly treated for hypothyroidism. Not everyone shares the same dilemma regarding treatment of hypothyroidism because T4 by itself may be sufficient in many instances. But for those who continue to experience symptoms of hypothyroidism despite T4 treatment, adding T3 can be a life changing experience.

Here is Sarah’s story:

I was diagnosed with hypothyroidism in my early twenties and Synthroid did not help. I did not know at the time that many of my symptoms were due to hypothyroidism. After changing to my long time physician, I told her of my original diagnosis some years back. She did only the TSH and told me I was no longer hypothyroid! So for some 15 years after being in her care and continuing to feel crummy, then for the last 8 steadily gaining weight and feeling worse, I was not on any medication. I begged her for Cytomel several years back and was denied…she said she didn’t treat with that. When I finally was deemed hypo by her, she put me on the smallest dose of levothyroxine. It did not help. I finally went to see a shrink and he put me on 25 mcg of Cytomel. For the first time in my post pubescent life, I feel like living. My dose was upped to 50, and I felt even better but my thyroid levels were off, so we are now working on that and I am back to 25 mcg per day. If you can’t get Cytomel from your regular physician, you might get a psychiatrist to prescribe it. It changed my life and I finally feel alive. I’ve since switched primary physician because she wouldn’t listen to me, and she didn’t like that I was on Cytomel. I don’t know what it is about this medication that regular physicians don’t like and make them refuse to treat with it, especially when so many can benefit from it. I’ve lost only 12 lbs since being on it, but I gained nearly 35 unnecessarily while not being properly treated and was told to eat less and exercise more…I only ate about 1500 calories a day and walked my dog 2 miles each day, so I don’t feel it had anything to do with my diet!

What is My Correct Thyroid Dose?


Lots of members at metabolism.com with hypothyroidism ask what is their correct thyroid hormone dosage. For those who are still confused I am posting the latest Q and A addressing this issue.

Member ecchho received radioactive iodine for hyperthyroidism (over-active thyroid) and as commonly happens, developed hypothyroidism (under-active thyroid). Despite t4 levels which appear to be normal symptoms persist, so ecchho inquires about ways of dealing with this common problem.

Here is the Q and A regarding ecchho’s post:

Hi Dr. Pepper:

I had Graves disease at 23 and then had RAI at 28 and have been on synthroid for 18 years. I did try ARmour once, but I found it had too much t3 (I think the pig’s ratio of t4 to t3 is much more potent than humans) and I actually had a real hard time regulating. I don’t have a thyroid anymore, and I take 225 synthroid. i still suffer a bit with impossible weight loss (despite running, dieting, etc) and some depression that feels quite hormonal at times. My dr. brought up adding t3 last visit and tested me, and then said, oh, you don’t need any xtra t3, you seem to be converting fine.
what are the levels that the t3 should be, and is this free t3 or t3? thanks.

My reply to Ecchho’s post:

Your question regarding the correct level for thyroid functions, is frequently raised on this website. I would respond to your question with this question, ” What is the correct shoe size?” Obviously, the answer is, whatever shoe size fits best. Similarly with thyroid function, everyone has a different “comfort zone” where their body functions best. That is their “correct” thyroid hormone level. You also refer to a t4 to t3 ratio for pigs versus humans. These ratio’s are averages of several hundred individuals (human or pig)and do not apply to any particular individual. Some people function better at a t3 to t4 ratio which is higher than the average. As pointed out in my article,https://www.metabolism.com/2009/11/07/breakthrough-discovery-thyroid-hormone-therapy-part-2/ , there is recent evidence that due to genetic differences, a percentage of the population does not convert t4 to t3 efficiently and therefore are likely to require t3 supplementation when treated for hypothyroidism.

Rather than spend the money for genetic testing to discover whether the genes for conversion of t4 to t3 are abnormal, some doctors recommend simply adding an appropriate dose of t3 to the standard t4 (levothyoxine)treatment and following the patient for improvement in clinical symptoms. You might want to consider discussing this approach with your doctor.

Gary Pepper, M.D

How to Talk to Your Doctor About Thyroid Medication


Mary…you’ve made my day! I am glad you found my suggestion about “how to talk to your endocrinologist”, helpful. I am absolutely serious about approaching your physician in this way, since it makes them aware valid new information is available explaining why some people need t3 to recover from symptoms of hypothyroidism. This approach is much more likely to elicit a sympathetic response from a physician than quoting from a book by a non-physician or using the more general “I read it on the internet” statement.

Here is what Mary had to say to metabolism.com:

Dr Pepper, thank you so much for this article. I love the last part of where you give us the perfect phrases to say to our doctor. I have been suffering with hypothyroidism for 14 years now (10 years undiagnosed, 4 years insufficiently treated). Over these years I have come to know quite a bit about my condition and can speak with my doctor using the correct terminology most of the time, but not always (I have to get through the brain fog). Your phrases are just what I need to say to my doctor since I believe I have a conversion problem. I will enjoy presenting the study to him an talking to him about polymorphism and deiodinase! 🙂 Some people tell me I should have changes doctors along time ago. My doctor may have given up on me but I will not give up on him. I am determined to educate him. He did recently admit to me that he doesn’t know much about the thyroid. I fail to understand why the vast majority of General Practitioners don’t get up to speed on this subject since so many of their patients are suffering from thyroid problems. My doctor has wasted time and money giving me anti-depressants and appetite suppressants (Reductil) and sending me to a counsellor. Thanks again for helping.

Wondering if t4 (Synthroid) Treatment of Hypothyroidism is the Answer


Prosanta asks metabolism.com if her thyroid blood test results indicate that treatment with t4 is required. I suspect that she is also wondering if other forms of treatment might be better (Armour Thyroid for example).

Here is what Prosanta writes:

Iamsuffering from Diabetes type2.recently on routine Blood test—
FT3(ECLIA) 2.33pg/ml
FT4 1.07ng/ml
TSH 9.32microIU/ml
AntiThyroid Peroxidase 37.02IU/ml
Do I need to take only Levothyroxine

In response to her question I offer my thoughts on whether someone beginning with thyroid hormone replacement therapy should start with t4.

Hi Prosanta

You know I can’t recommend medical therapy in this forum. I can make some general comments, however.

There is debate among endocrinologists about what level of TSH indicates a clinical degree of thyroid deficiency, but there is no doubt that a TSH of 9 is abnormally high. Since elevated TSH almost always indicates that the pituitary gland is releasing excessive TSH in response to thyroid hormone deficiency, unless there is a pituitary tumor (exceedingly rare), replacement therapy with thyroid hormone is indicated.

Thyroid hormone replacement therapy in the U.S. usually consists of taking a pure t4 product such as Synthroid or levothyroxine (generic t4). On this website you will notice extensive posting about treating hypothyroidism with alternative forms of thyroid hormone replacement, particularly desiccated thyroid products such as Armour Thyroid. An appropriate concern in a situation like yours is whether to take t4 only or to use desiccated thyroid or t4 plus t3 therapy.

If you are like most people in this country being treated with t4, you will wonder why someone might need alternative forms of thyroid hormone replacement. In the past year or so researchers have discovered that a portion of the population lacks the ability to normally metabolize t4 into the highly biologically active t3. This means that affected individuals may continue to experience symptoms of thyroid hormone deficiency when treated with conventional t4 therapy [https://www.metabolism.com/2009/11/07/breakthrough-discovery-thyroid-hormone-therapy-part-2/ ]. How does a person know if they won’t respond to t4? The simpliest approach is to try t4 and see how you feel. Then you and your doctor can decide whether you are a t4 responder or not.

You may be aware that Armour Thyroid and similar products are in very short supply in the U.S. Even if some advocates of desiccated thyroid therapy for hypothyroidism argue that only desiccated thyroid can result in a full return to normal, in my opinion the present shortage makes t4 therapy the clear initial choice. If symptoms of hypothyroidism persist even after a full course of t4 has been tried, then you may be forced to join the ranks of those struggling with the pharma industry to get desiccated thyroid products.

Please discuss these ideas with your own physician.

The disclaimer and terms of service of metabolism.com applies to this and all my posts on this website.