Screen Shot 2015-05-05 at 5.37.04 PMWhat is Synthroid?

Synthroid is a brand name of the thyroid storage hormone T4 and made by Abbott Laboratories for many years. It’s the most well-known brand name for what’s called levothyroxine sodium, a synthetic, man-made version of the thyroid hormone T4.

Technically, it’s a synthetic, man-made crystalline L-3,3′,5,5′-tetraiodothyronine sodium salt. Doctors have been prescribing Synthroid for over 50 years to treat hypothyroidism. Before that time, the only treatment for hypothyroidism was natural desiccated thyroid, which appeared to work well for a good seven decades before Synthroid entered the arena due to a single bad batch of NDT which came into the United States. See more details in Chapter 1 of the revised STTM book.

Inactive ingredients include acacia, confectioners sugar (contains corn starch), lactose monohydrate, magnesium stearate, povidone, and talc. These fillers may be different in other brands of T4-only. The Synthroid sizes ranges from 25 mcg all the way to 300 mcg.

What is T4?

T4 is one of five hormones made by your thyroid gland– the latter which includes T4, T3, T2, T1 and calcitonin. T4 is a storage pro-hormone with the purpose of converting to the active hormone T3, though the thyroid also makes some direct T3 as well. T3 is the hormone which gives health and energy to every cell in the body. See Chapter 1 in the revised STTM book for more info on these thyroid hormones.

What are other brands similar to Synthroid?

Levoxyl, Levothroid, Unithroid, Berlthyrox, Eltibio, Eltroxin, Eutroxsig, Oroxine, Droxine, Eferox, Elthyrone, Euthyrox, Eutirox, generic levothyroxine, and more. They can have different fillers.

What’s the history of Synthroid or T4-only medications?

This is covered in Chapter One of the revised Stop the Thyroid Madness book with interesting detail.

Is Synthroid an adequate treatment for hypothyroidism? Does Synthroid work?

The answer is varied according to the reported experiences of patients.

1. For some, yes, it does provide some relief of some hypothyroid symptoms due to conversion to T3..

2. For others, it fails from the beginning, leaving unresolved problems unique to each individual, resulting in continuing and worsening hypothyroid symptoms the longer one stays on it.

3. For the majority of those who initially found some success, there is clear reported evidence of growing or worsening symptoms of an inadequate treatment the longer Synthroid is used.

i.e hypothyroid patients report continuing hypothyroid symptoms in their own degree and kind, sooner or later, which can include lingering fatigue, the need to nap, poor stamina or strength, depression, rising cholesterol or blood pressure, dry skin or hair, digestive problems, easy weight gain, difficulty losing weight, a diagnosis of Chronic Fatigue Syndrome or Fibromyalgia, brain fog, anemia, low B12, adrenal issues and many more.

Browse this compiled, patient-reported list of lingering or worsening symptoms while on Synthroid or similar T4-only meds, and which only went away when they switched to a different thyroid medication with desiccated thyroid or T3. The kinds and severity are unique to each individual.

Why do hypothyroid patients on Synthroid see rising symptoms the longer they stay on?

T4 is a storage hormone meant to convert to the active and life-changing T3. It’s T3 which removes symptoms. But there are a myriad of issues which can hinder the conversion of T4 to T3, ranging from one’s genetic mutations, illnesses, chronic stress, too much exercise, poor eating habits, lyme disease, mold exposure… to even your body aging. And there are more reasons.

Is there an issue with Synthroid being synthetic?

In a particular STTM blog post written by Janie Bowthorpe in 2012, she refers to an article with an interesting viewpoint, stating that synthetic T4-only medications like Synthroid are “unfortunately a mix of the left handed nature-made combination of molecules, aka L-(Laevorotary), along with the synthetic, man-made right handed version, aka D-(Dextrorotary), i.e. the latter is a mirror-image, not a direct image.” As a result, one ends up with a lot of waste products, states the author of the article, and not the true T4. She presents it as food for thought.

Where can more information about the problem of T4-only meds be found?

The T4-only Meds Don’t Work page gives a good outline of why these medications don’t work for a large body of patients and why.

Chapter One in the revised Stop the Thyroid Madness book also contains more details of the problem of Synthroid or other T4-only medications.

If a patient doesn’t want to be on Synthroid or other T4-only meds, what’s another choice?

Patients report getting far better results with Natural Desiccated Thyroid hormones. Even adding T3 (Cytomel) to T4 has been reported to give better results than T4-only.

My doctor refuses to prescribe anything other than Synthroid. What do I do??

Important note: STTM is an information-only site based on what many patients worldwide have reported in their treatment and wisdom over the years. This is not to be taken as personal medical advice, nor to replace a relationship with your doctor. By reading this information-only website, you take full responsibility for what you choose to do with this website's information or outcomes. See the Disclaimer and Terms of Use.