The Little-Known Secret About Coffee and Your Thyroid

If you are drinking coffee at the same time you take your thyroid hormone replacement medication, you could be sabotaging your thyroid treatment,. istockphoto

If you are drinking coffee at the same time you take your thyroid hormone replacement medication, you could be sabotaging your thyroid treatment, and your health.

You may not see a warning on the drug leaflet you get from the pharmacist, and you may not be told this by your physician, but the impact of coffee on absorption of your thyroid medication has been studied and scientifically documented.

A study published in the journal Thyroid found that women who had a high or high-normal Thyroid Stimulating Hormone (TSH) levels, and who took their thyroid medication with coffee, had substantial lowering of the medicine's absorption and impact -- reducing the effectiveness of the medication by as much as 36%.

That's like cutting your dose by one-third, or forgetting to take your pill one out of every three days.


When absorption of your medication is impaired, your TSH will rise, levels of T4 and T3 (the active thyroid hormones) will drop, and you will likely experience hypothyroidism symptoms, such as fatigue, weight gain, mood changes, and more. For a detailed list of hypothyroidism symptoms, see the Hypothyroidism Symptoms Checklist.


There are four things you can do to manage the possible interactions between coffee and your thyroid medication:

  1. This impaired absorption was not seen in women who took their medication with water and waited an hour before drinking coffee. So you can take your medication, and then wait an hour before having your coffee.
  2. If you regularly awake in the middle of the night, you can take your medication, and go back to bed. As long as it's at least an hour, that will allow you to have coffee when you awake.
  1. If your doctor agrees, you may be able to take your thyroid medication at bedtime, instead of the morning.
  2. If you are on a levothyroxine tablet (like Synthroid or Levoxyl), you can switch to the liquid capsule form (Tirosint). Studies have shown that coffee does not affect the absorption of Tirosint -- essentially, Tirosint is "coffee-resistant." Tirosint is designed for patients with allergies, digestive issues, and absorption problems.

    Note: The caffeine content of the coffee does not have an effect -- it's components of the coffee (caffeinated or decaf) that affects absorption. So switching to decaffeinated coffee is not a solution.


    Read more about coffee and your thyroid medication.


    Benvenga, S. et. al. "Altered intestinal absorption of L-thyroxine caused by coffee." Thyroid. 2008 Mar;18(3):293-301. doi: 10.1089/thy.2007.0222. Abstract.)

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