Thyroid-Friendly Smoothies

by Mary Shomon Patient Advocate

Who can resist a creamy, delicious, healthy smoothie? These beverages are growing in popularity, and the global market for smoothies is projected to reach $17 billion dollars by 2024! But for people with thyroid problems, some popular smoothie ingredients and preparation methods are not thyroid-friendly. Let’s take a look at how you can enjoy smoothies without getting in the way of good thyroid health.

Green vegetables.

Watch out for goitrogens

Goitrogens are foods that contain a chemical — thiocyanate — that can slow down your thyroid. Many common smoothie ingredients are goitrogens, including cabbage, cauliflower, spinach, kale, and watercress. Smoothies made from dark leafy greens, are, in fact, a growing sector of the smoothie market. Avoid making smoothies with raw or boiled goitrogenic foods. But don’t avoid them entirely. Cooking or steaming can deactivate most of their anti-thyroid effect.

Soy foods.

Minimize the soy

Soy and soybean products can promote an enlarged thyroid (goiter) and hypothyroidism, so don’t add soy milk, tempeh, tofu, or soy protein powder to your smoothies. For protein powder, try whey or pea protein for thyroid-friendlier smoothies. If you’re determined to use soy in your smoothies, make sure that your diet includes enough iodine, which can help offset the impact of soy.

Fruit smoothies.

Hold the green tea

Whether you’re at Starbucks or Smoothie King, you’ll find green tea on the smoothie menu. But you may want to give it a pass. Too much green tea can significantly reduce thyroid hormone levels, and make your thyroid stimulating hormone (TSH) level go up.


Be careful about seaweed and sea vegetables

Seaweed — and other sea vegetables like kelp and dulse — are healthy and delicious. They are also very high in iodine. If you have been tested and shown to be deficient in iodine, by all means include them in moderation in your smoothies. But if you are not deficient in iodine, loading up your smoothies with seaweed, kelp powder, or dulse flakes can aggravate autoimmune thyroid disease, create worsening hypothyroidism symptoms, and even increase your risk of thyroid cancer.

Woman refusing a glass of milk.

Skip the milk in your morning smoothie

If you like to add milk to your smoothie, remember that the calcium in milk can interfere with the absorption of thyroid drugs used to treat hypothyroidism.

There are solutions, however:

  • Swap your cow’s milk for a lower-calcium alternative like almond or rice milk.
  • Wait at least an hour after taking your thyroid medication before you drink your smoothie.
  • Save your smoothie for later in the day, when it won’t impact your thyroid treatment.
Flaxseed in bowl and spoon.

Be aware of the impact of fiber

Some people like to add psyllium, flaxseeds, flax powder, chia seeds, or other high-fiber ingredients to smoothies. You should know, however, that going from low- to high-fiber intake can reduce your absorption of thyroid hormone replacement medication and make you more hypothyroid. If you start drinking high-fiber smoothies, have your thyroid levels rechecked eight to 12 weeks after making the change, so your medication dosage can be adjusted if necessary.

Healthy smoothies, purple and green.

Try chard

Many smoothie recipes contain kale, which is healthy, but is a goitrogen. You can steam kale before mixing it into the smoothie, however. Or replace the kale with non-goitrogenic and equally delicious chard.

Dr. Amy Myers’ Purple Passion Smoothie and other gut-healing, anti-inflammatory kale smoothies, all of which are delicious. Or try Reboot With Joe's delicious Thyroid-Friendly Pear & Chard Smoothie recipe.

Coconut products.

Join the coconut craze!

Coconut milk and coconut water are thyroid-friendly ingredients you can add to your smoothie. Check out The Hypothyroidism Chick's thyroid-friendly smoothie recipes, including the tantalizing Pina Colada and Bahama Mama Smoothies.

Fresh fruit smoothies.

Smoothies make a perfect breakfast

Functional medicine expert Mark Hyman, M.D. has some healthy breakfast smoothie recipes that are good for your thyroid and can help with weight loss. I love his Strawberry-Almond-Coconut, Ruby, and Cocoa Bliss Smoothies!

Smiling woman making green smoothies in blender.

Try making your own smoothies

Experiment with various smoothie recipes to create thyroid-friendly variations of the ones you love best. Here are some good places to start for other smoothie recipe ideas:

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.