Your experiences with thyroid medication, part I

Results of Boost Health survey

In our survey, we asked you about your experiences with the thyroid therapy you are currently on. It is an anonymous survey, with an aim to learn what and how many side effects are present and how does the successful therapy look and feel like.

You can still participate in the survey, we will update results regularly on our blogand our Facebook page.

We collected enough data for Levothyroxine (containing T4 only) and Natural thyroid preparations (containing a mix of T4 and T3) therapy. We did not collect enough data on the combination of Levothyroxine and Liothyronine (a synthetic mix of T4 and T3), and for that reason, we decided not to present results on Levothyroxine and Liothyronine in this first part of analysis. If you are using this combination therapy and interested in sharing your experiences, we would love to hear more from you too.

Please keep in mind that results of this survey might not represent the global averages.


54% of you is using Levothyroxine, 36% of you is using Natural thyroid preparations and 10% of you is using a combination of Levothyroxine and Liothyronine.


Levothyroxine is still the preferred and usually the first therapy choice for most of the healthcare professionals.It is substituting for the lack of T4 in the body, and should in principle work well for people that can convert T4 into T3, an active form of thyroid hormone. 1 in 10 of people with the hypothyroid condition cannot convert T4 into T3 because they miss the enzyme called deiodinase [1, 2].

Levothyroxine is good for restoring blood levels of TSH to what is considered a “normal” value. However, metabolism remains 10%- 20% less efficient, making it hard to maintain a healthy weight [3, 4]. High cholesterol levels, often experienced in hypothyroidism, seem not improve with Levothyroxine treatment [5, 6].

Natural thyroid preparations

Natural thyroid, or desiccated thyroid, preparations are made from thyroid glands of domestic animals and contain both T3 and T4. In the last couple of years, natural thyroid preparations are becoming more commonly prescribed.

Although they do contain a mix of T4 and T3, the ratio of T4 — to — T3 is different than what is found in a human with a healthy functioning thyroid, resulting in 3.3x more T3. This condition of excess of thyroid hormone is called thyrotoxicosis [7].

Symptoms experienced after the treatment

For people using Levothyroxine, two most common side effects are brain fogand anxiety, results are in line with what research has shown so far [8]. The symptoms might come from high T4 levels.

For people using Natural thyroid, two most common side effects are fatigueand brain fog. The symptoms might come from high T3 levels.

It is possible these symptoms are triggered by other than medication, namely the lifestyle, such as excessive or high-intensity exercise or dietary habits. High intake of sugars or foods causing an immune reaction in the gut can be the cause of symptoms.

Therapy dosage adjustments

More than half of you adjusted your dose at least once in the past two years, with newly diagnosed people on average having 2x more adjustments than the people diagnosed more than 3 years ago.

Want to know more?

If you want to discover more about what lifestyle choices could work specifically for you, we invite you to chat with Hashiboto, a virtual assistant for thyroid. All of our information and insights are coming from peer-reviewed scientific journals.

We do not give out medical advice, you and your healthcare provider are the only people to talk about what kind of treatment is the best for you personally.


1. Jonklaas J, et al. American Thyroid Association Task Force on Thyroid Hormone Replacement. Guidelines for the treatment of hypothyroidism: prepared by the American Thyroid Association Task Force on Thyroid Hormone Replacement, 2014

2. Wiersinga WM, et al. 2012 ETA guidelines: the use of L-T4 + L-T3 in the treatment of hypothyroidism, 2012

3. Cotton GE, et al. Suppression of thyrotropin (h-TSH) in serums of patients with myxedema of varying etiology treated with thyroid hormones, 1971

4. Gorman CA, et al. Comparative effectiveness of dextrothyroxine and levothyroxine in correcting hypothyroidism and lowering blood lipid levels in hypothyroid patients, 1979

5. National Cholesterol Education Program (NCEP) Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults (Adult Treatment Panel III) Third Report of the National Cholesterol Education Program (NCEP) Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults (Adult Treatment Panel III) final report. Circulation, 2002

6. Tanis BC et al. Effect of thyroid substitution on hypercholesterolaemia in patients with subclinical hypothyroidism: a reanalysis of intervention studies, 1996

7. Jonklaas J, et al. Guidelines for the treatment of hypothyroidism: prepared by the american thyroid association task force on thyroid hormone replacement, 2014

8 Hoffenberg R. Primary hypothyroidism, 1978