The Wellness Library

3 Common Chemicals That Could Impact Your Thyroid

by | Jun 3, 2020 | Thyroid Health

Washing hands

We’ve regularly talked about the thyroid gland’s vital role in your body’s ability to function well. The thyroid hormone, which the gland produces and releases a steady stream of into your bloodstream, is used by essentially every cell in your body. So what happens if the thyroid gets off balance? Or something else in your body starts circulating thyroid hormones? That’s what we’re breaking down today: how common chemicals you come into contact with maybe every day can impact your thyroid.

How Thyroid Hormone is Made

A structure in the brain, called the anterior pituitary, releases thyroid stimulating hormone (TSH) to communicate with your thyroid gland to produce thyroid hormone. When your brain sends your thyroid approval to make more thyroid hormone, it takes its major building blocks, iodine and tyrosine, and fuses them together via a variety of steps.

This production primarily produces the prohormone, thyroxine (a.k.a T4). As your tissues demand it, the prohoromone may also go through a step called deionisation. This is a fancy word for the process of plucking off one iodine from T4 to form the thyroid’s most metabolically active form of hormone—triiodothyronine (a.k.a. T3). Both are important for optimal body function, but let’s dive into the benefits of T3.

How T3 (Triiodothyronine) Benefits the Body

T3 is a crucial hormone that your body needs to:

  • Regulate body temperature. 
  • Influence heart rate and rhythm.
  • Help with maturation of brain and growth development in children.
  • Improve concentration and faster reflexes through the nervous system.
  • Provide proper metabolism of energy resources.

Without T3, your body will feel a little out of whack. The good news? You may be able to impact your thyroid hormone production with a few simple changes.

The Effects of Halogens on Thyroid Hormone Production 

Do you remember being back in chemistry class learning about the periodic table of elements? In that table, there’s a class of elements labeled “Halogens.” The Halogens category includes 6 elements—and 3 of those can have a significant impact on your thyroid hormone production.

Here’s how: Remember I told you that iodine is a major building block to synthesize thyroid hormone, whether that be T4 or T3? Iodine can be out-ranked by its bigger brothers—fluorine, chlorine, and bromine. When you’re exposed to higher levels of these “bigger” halogens, research shows that you can experience negative impacts in the production of your thyroid hormone. Here’s how.

3 Common Chemicals That Could Impact Your Thyroid


Fluorine is found in the form of Fluoride in toothpaste, mouth rinses, drinking water, medical imaging scans, cleaning agents, pesticides, and in items such as Teflon, steel, and aluminum products. Although Fluoride is a mineral found in healthy bones and teeth, there’s debate on what constitutes safe exposure levels.

High doses of Fluoride have been associated with several health concerns. It has the ability to block the iodide transport process in your body’s production of thyroid hormone. This can cause antithyroid effects by reducing thyroid hormone production and raising your TSH levels through a negative feedback loop. Higher TSH levels can be indicative of an under-active thyroid, and lead to hypothyroidism.


Chlorine is a common disinfectant. It’s added to pools, drinking water, and many cleaning products. Chlorine has been shown to lower T4 levels, and suppress T3, both causing antithyroid effects. 


Bromine, in concentrated numbers, works similar in nature to Fluorine and Chlorine, competing for the same receptors that help to take up iodine for thyroid hormone production. Studies have shown that Bromine can induce alterations in cellular structure and can reduce T4 and T3 levels.

Bromine can be found naturally in some foods, but more often than not, bromine exposures come from bromine-fortified foods, beverages, sanitizers, and flame proofing agents. Pesticides contain methyl bromide, and can be found on commonly sprayed fruits (such as strawberries), bakery goods that contain potassium bromate, soft drinks that are made with brominated vegetable oils, and polybrominated diphenyl ethers (PBDEs), chemicals that are used in carpets, mattresses, and upholstery as flame retardants. 

What You Can Do to Help Prevent Unwanted Halogen Exposures, and Reduce Thyroid Issues

Much like with your personal care and beauty products, there’s no need to panic and swap everything you’re using immediately. As you run out of products or as you’re considering your next food and beverage purchases, consider these tips to reduce your Halogen exposure:

  • Drink filtered or reverse osmosis water (don’t forget to add in minerals to reverse osmosis water!)
  • Refer to the Environmental Working Group’s (EWG) Clean 15 and Dirty Dozen to help navigate which foods are better to buy organic. Organic fruits and vegetables help to reduce unwanted pesticide exposure. 
  • Use natural cleaning products such as Branch Basics or Dr. Bronner’s.
  • Limit the amount of time you spend in chlorinated swimming pools, and always rinse off after.
  • Avoid processed foods and beverages, and opt to buy locally grown, fresh foods.
  • Swap out fluoridated toothpastes and mouthwash, for fluoride-free.
  • And if you want to get really serious, look for GOTS certified textile products! GOTS third-party certification that requires products be at least 95% organic fiber; not be treated with bleach, formaldehyde, or other toxic substances; be colored with nontoxic dyes; and be produced in a mill that enforces strict social and environmental standards. We’ve got a few ideas for home goods you can check out here.

If you’re looking for further guidance on cleaning up your household, or you’re wondering if your symptoms could be thyroid related, schedule a visit with one of our practitioners to get more info, tailored to your health needs.



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