Your Guide to Thyroid Support Supplements

by Mary Shomon Patient Advocate

If you are hypothyroid, even if you are taking prescription thyroid hormone replacement medication, you may have lingering symptoms. Many thyroid patients complain of unresolved fatigue, weight gain, mood changes, hair loss, and other symptoms, even after what is considered optimal hypothyroidism treatment.

If you are still struggling to manage your symptoms, you may decide to add thyroid-support supplements to your overall treatment. Your first step in finding one, like many people, is to search the internet. Or, you may consult a holistic healthcare provider, such as a naturopathic physician, nutritionist, herbalist, or even ask the clerk at your local vitamin store for a recommendation.

Along the way, you will discover there are dozens of supplements that claim to be designed specifically for thyroid support. They are typically labeled "thyroid support," "thyroid energy," "thyroid booster," "thyroid help," "thyroid complex," among other variations on "thyro…" followed by various health claims.

Before you start taking any thyroid support supplement, learn about the most common and popular ingredients you are likely to find in these products, pros and cons, and some cautions you should keep in mind.

Common ingredients in thyroid-support supplements

Most thyroid-support supplements contain one or more of the following ingredients.

  • L-tyrosine - an amino acid that is needed for the production of thyroid hormone

  • Iodine - the mineral that is the necessary and essential ingredient for the production of thyroid hormone

  • Seaweed, kelp, and bladderwrack - sea vegetables that are high in iodine

  • Selenium - a mineral that helps facilitate T4 to T3 conversion, and can lower thyroid antibodies

  • Thiamine (Vitamin B1) - a vitamin that can help resolve fatigue in people with thyroid conditions

  • B vitamins, including B12 (cyanocobalamin), B2 (riboflavin), and B6 (pyridoxine) - for general energy and overall thyroid function

  • Raw thyroid/thyroid glandular/glandular "complex"/ bovine thyroid tissue - thyroid and other glandular tissue from animals

  • Ashwagandha - an adaptogenic Ayurvedic herb used to help support the thyroid and adrenal glands, and improve energy

  • Coleus forskohlii - a botanical that helps improve the uptake of iodine into thyroid cells

  • Guggul - also known as commiphora mukul, guggul is an extract of the sap of the Indian myrrh tree that helps enhance T4 to T3 conversion

There are also some specialized thyroid support supplements designed for metabolism and/or weight loss. Some of these products include:

  • Probiotics - to help heal gut inflammation that may be a trigger for autoimmune thyroid disease

  • Korean ginseng and Panax ginseng - to increase metabolism and improve energy

  • Green tea/green tea extract - to help support the ability to burn fat

  • Garcinia cambogia - a plant-based supplement purported to help curb appetite and burn fat

  • Caffeine - to increase calorie-burning and improve energy

Benefits of thyroid support supplements

In some cases, thyroid support supplements may help reduce hypothyroidism symptoms. For example, there is proven research to show the benefits of iodine, selenium, thiamine, and probiotics for various aspects of thyroid disease.

The challenge is in knowing which specific minerals, vitamins, amino acids, or herbs you actually need, and which ones could potentially create more problems. That is truly not a do-it-yourself project and would be better accomplished with the guidance of a knowledgeable healthcare provider.

Then there is also an issue of dosage of ingredients in thyroid support supplements.

For example, research shows that daily supplementation with thiamine, a common ingredient in these supplements, can quickly help relieve fatigue in patients with Hashimoto's and hypothyroidism. Most thyroid support supplements, however, contain no more than about 10 to 25 mg of thiamine - well below the 650 mg per day needed to help relieve thyroid-related fatigue.

Selenium is another nutrient that has been proven to improve T4 to T3 conversion and lower thyroid antibodies. Most thyroid support supplements that contain selenium, however, only have 20 to 50 mcg, well below the recommended 200 to 400 mcg per day that should be ingested -- from all sources combined, including food - to obtain benefits.

Iodine is also a concern. Most thyroid support supplements have reasonable - but low - levels of iodine, ranging from 50 to 200 mcg. Some thyroid patients, however, may have significant iodine deficiency that requires significantly higher doses.

If you are not iodine deficient, adding too much iodine can worsen your thyroid problem. While many of the capsules and tablets contain 50 to 100 mcg of iodine per capsule, if you take them as recommended, you can easily start ingesting up to 1000 mcg (or 1 mg) - a level that could be problematic if you are not deficient in iodine. Also, keep in mind that seaweeds such as kelp, a popular ingredient in many thyroid supplements, are very high in iodine. One serving or tablet of some kelp products can have as much as 800 mcg to 1 mg of iodine.

Ideally, you should have your iodine levels tested, and supplement accordingly only if you are deficient.

Downsides of thyroid support supplements

Thyroid support supplements also raise three key concerns for thyroid patients.

Thyroid hormone content. Many thyroid support supplement brands contain actual thyroid hormone. In 2013, the journal Thyroid published research that found that the majority of over-the-counter thyroid-support supplements evaluated in one study contain detectable amounts of thyroid hormone.

Thyroid hormone was found in many of the supplements that were labeled as raw thyroid/thyroid glandular or listed thyroid tissue as an ingredient. But of additional concern is the fact that thyroid hormone was also found in supplements that claimed to contain only vitamins and herbs, and did not list a glandular as an ingredient.

The study actually found that 9 out of the 10 popular thyroid supplements evaluated had detectable amounts of triiodothyronine (T3), and one tablet contained a whopping 25 mcg of T3. Four out of the 10 products studied had thyroxine (T4) at levels from 8.5 mcg up to 91 mcg. These are levels that may easily exceed a daily prescription dose of thyroid medication for many people. Popping these supplements in multiple quantities or several times a day could easily push you into overmedication and medication-induced hyperthyroidism. The risk is even greater when you are already taking prescription thyroid hormone medication along with these supplements.

The potential for contamination from cow/bovine sources

You need to be careful about cow glandulars, also known as bovine tissue, because they can be infected with prions. In evaluating these products, Consumer Reports senior scientist Michael Hansen, Ph.D. said:

"Ingesting ingredients like these is not wise. Supplements that contain pituitary or brain products from cows could theoretically pose a risk for Creutzfeldt-Jakob, a rare disease that occurs in humans and causes brain tissue to degenerate rapidly. The disease has been linked to eating material from cows infected with mad cow disease … Those prions are far harder to kill than bacteria or viruses, so processing or treating the organs before adding them to supplements won't necessarily eliminate the risk."

Holistic physician, Andrew Weil, M.D., usually an outspoken proponent of vitamins and supplements, is also not a fan of thyroid supplements that contain glandular material. Dr. Weil says:

"Manufacturers claim that they can enhance immune function, correct hormonal imbalances, treat allergies, and combat inflammation. Some are said to have rejuvenating effects. I know of no credible evidence demonstrating that these products live up to their advertised effects. (Also) … these products may contain toxic contaminants and could, theoretically, transmit diseases like mad cow disease. Bottom line: At best, glandular extracts are a waste of money. At worst, they could be dangerous. I strongly recommend against using these products."

Supplements are not a substitute for prescription thyroid medication.

You may want to treat your hypothyroidism without a prescription, but there is also no way to know whether a particular thyroid supplement contains any actual thyroid hormone, and if so, how much. Over-the-counter thyroid support supplements are not a reliable, safe or effective alternative to prescription thyroid hormone medication you take to treat your hypothyroidism.

If you are going to take a thyroid support supplement …

If you are going to take a thyroid support supplement, here are two key guidelines.

First, it's best to work with a knowledgeable healthcare provider, who can provide guidance on choosing a thyroid supplement when needed. A practitioner can also test for any deficiencies before starting supplementation.

Second, if you are going to take a supplement product that contains glandular material, ask your practitioner to recommend a specific brand that he or she knows to be safe and free of toxins or disease. Also, be sure that any thyroid supplements label the country of origin of animal-glandular products. Glandular materials should also come only from toxin-free, free-range animals whose grazing areas are free of pesticides, growth hormones, antibiotics, or chemical additives.

Mary Shomon
Meet Our Writer
Mary Shomon

Mary Shomon is a patient advocate and New York Times bestselling author who empowers readers with information on thyroid and autoimmune disease, diabetes, weight loss and hormonal health from an integrative perspective. Mary has been a leading force advocating for more effective, patient-centered hormonal healthcare. Mary also co-stars in PBS’ Healthy Hormones TV series. Mary also serves on HealthCentral’s Health Advocates Advisory Board.