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Selenium TR

Generic name: seleniumse-LEE-nee-um ]
Drug class: Minerals and electrolytes

Medically reviewed by on Aug 11, 2023. Written by Cerner Multum.

What is Selenium TR?

Selenium TR is mineral that is found in soil and occurs naturally in certain foods (such as whole grains, Brazil nuts, sunflower seeds, and seafood). Selenium TR is not produced in the body, but it is needed for proper thyroid and immune system function.

Selenium TR is used to treat or prevent Selenium TR deficiency.

Selenium TR has been used in alternative medicine as an aid to treat Hashimoto's thyroiditis (an autoimmune disorder of the thyroid), and to treat high cholesterol.

Not all uses for Selenium TR have been approved by the FDA. Selenium TR should not be used in place of medication prescribed for you by your doctor.

Selenium TR may also be used for purposes not listed in this product guide.

Selenium TR side effects

Get emergency medical help if you have any of these signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

Long term use of high Selenium TR doses can lead to dangerous side effects. Stop taking Selenium TR and call your doctor at once if you have:

  • nausea, vomiting;

  • lack of energy, feeling irritable or very tired

  • hair loss, mild rash, brittle or painful fingernails, or white streaks on the nails;

  • tremors, feeling light-headed;

  • muscle tenderness;

  • flushing (warmth, redness, or tingly feeling);

  • metallic taste, bad breath, strong body odor; or

  • easy bruising or bleeding.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.


High doses or long-term use of Selenium TR can lead to serious medical problems or death. Do not use more of this product than is recommended on the label.

Follow all directions on your medicine label and package. Tell each of your healthcare providers about all your medical conditions, allergies, and all medicines you use.

Before taking this medicine

You should not use this product if you are allergic to Selenium TR.

Using Selenium TR long-term or at high doses may increase your risk of developing diabetes or other serious medical conditions. Ask your doctor about your specific risk.

Before using Selenium TR, talk to your healthcare provider. Your dose needs may be different if you have:

Your dose needs may be different during pregnancy or while you are nursing. Do not use this product without medical advice if you are pregnant or breast-feeding a baby.

Do not give any herbal/health supplement to a child without medical advice.

How should I take Selenium TR?

When considering the use of herbal supplements, seek the advice of your doctor. You may also consider consulting a practitioner who is trained in the use of herbal/health supplements. If you choose to use Selenium TR, use it as directed on the package or as directed by your doctor, pharmacist, or other healthcare provider.

Long-term use of Selenium TR in doses greater than 400 micrograms (mcg) per day can lead to serious medical problems or death. Do not use more of this product than is recommended on the label.

The recommended dietary allowance of Selenium TR increases with age. Follow your healthcare provider's instructions. You may also consult the National Academy of Sciences "Dietary Reference Intake" or the U.S. Department of Agriculture's "Dietary Reference Intake" (formerly "Recommended Daily Allowances" or RDA) listings for more information.

If you need surgery, tell the surgeon ahead of time that you are using Selenium TR. You may need to stop using this product for at least 2 weeks before your surgery.

This medication can affect the results of certain medical tests. Tell any doctor who treats you that you are using Selenium TR.

Store at room temperature away from moisture and heat.

What happens if I miss a dose?

Take the missed dose as soon as you remember. Skip the missed dose if it is almost time for your next scheduled dose. Do not take extra Selenium TR TR to make up the missed dose.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222. An overdose of Selenium TR can be fatal.

What should I avoid while taking Selenium TR?

Follow your doctor's instructions about any restrictions on food, beverages, or activity.

What other drugs will affect Selenium TR?

Other drugs may interact with selenium, including prescription and over-the-counter medicines, vitamins, and herbal products. Tell each of your health care providers about all medicines you use now and any medicine you start or stop using.

Popular FAQ

Food sources that are high in selenium include:

  • Brazil nuts: Just one or two nuts can provide a significant amount of selenium
  • Cottage cheese
  • Seafood: Oysters, clams, crab, tuna, halibut, and lobster are all rich in selenium
  • Meat: Beef, chicken, pork, ham, and turkey are all good sources of selenium
  • Eggs: Both the yolk and white eggs contain selenium
  • Grains: Some whole grains, such as wheat, barley, and rice, are good sources of selenium
  • Seafood: Oysters, clams, crab, and lobster are all good sources of selenium
  • Meat: Beef, chicken, and turkey are all good sources of selenium
  • Eggs (yolk and white)
  • Grains: Some whole grains, such as wheat, barley, and rice, are good sources of selenium, particularly if grown in soils rich in selenium.
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Further information

  • Consult with a licensed healthcare professional before using any herbal/health supplement. Whether you are treated by a medical doctor or a practitioner trained in the use of natural medicines/supplements, make sure all your healthcare providers know about all of your medical conditions and treatments.

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use this medication only for the indication prescribed.

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.