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On August 6, 2025, the Food and Drug Administration (FDA) announced plans to take action against manufacturers of unapproved animal-derived thyroid medications including those labeled as Armour®Thyroid, Dessicated Thyroid or Natural Thyroid. Manufacturers will have to cease distribution of these products until they have addressed the FDA's concerns. Patients taking these products should contact their healthcare providers to discuss transition to an alternative FDA-approved product. Contact your doctor or pharmacist if you have any questions. Additional information on this FDA notice can be found here: http://www.fda.gov/drugs/enforcement-activities-fda/fdas-actions-address-unapproved-thyroid-medications?utm_medium=email& utm_source=govdelivery
Thyroid hormone should not be used to speed weight loss in people who are overweight but do not have a thyroid condition. Thyroid hormone will not help speed weight loss in people with normal thyroid glands, and it may cause serious or life-threatening side effects in these people. The risk of serious side effects is even higher if thyroid is also taken with amphetamines such as benzphetamine (Didrex®), dextroamphetamine([Dexedrine®, in Adderall®), and methamphetamine (Desoxyn®).
Talk to your doctor about the risks of taking this medication.
WHY is this medicine prescribed?
Thyroid is used to treat the symptoms of hypothyroidism (a condition where the thyroid gland does not produce enough thyroid hormone). Symptoms of hypothyroidism include lack of energy, depression, constipation, weight gain, hair loss, dry skin, dry coarse hair, muscle cramps, decreased concentration, aches and pains, swelling of the legs, and increased sensitivity to cold. Thyroid is also used to treat goiter (enlarged thyroid gland). Thyroid is in a class of medications called thyroid agents. It works by supplying the thyroid hormone normally produced by the body.
HOW should this medicine be used?
Thyroid comes as a tablet to take by mouth. It usually is taken once a day before breakfast. Take thyroid at around the same time every day. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take thyroid exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.
Your doctor will probably start you on a low dose of thyroid and gradually increase your dose.
Thyroid helps control the symptoms of hypothyroidism, but does not cure this condition. It may take up to several weeks before you notice any change in your symptoms. To control the symptoms of hypothyroidism, you probably will need to take thyroid for the rest of your life. Continue to take thyroid even if you feel well. Do not stop taking thyroid without talking to your doctor.
Are there OTHER USES for this medication?
This medication is sometimes prescribed for other uses; ask your doctor or pharmacist for more information.
What SPECIAL PRECAUTIONS should I follow?
Before taking thyroid,
What SPECIAL DIETARY instructions should I follow?
Unless your doctor tells you otherwise, continue your normal diet.
What should I do IF I FORGET to take a dose?
Take the missed dose as soon as you remember it. However, if it is almost time for the next dose, skip the missed dose and continue your regular dosing schedule. Do not take a double dose to make up for a missed one. Tell your doctor if you miss two or more doses of thyroid in a row.
What SIDE EFFECTS can this medicine cause?
Thyroid may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:
Some side effects can be serious. If you experience any of the following symptoms, call your doctor immediately:
Thyroid may cause other side effects. Call your doctor if you have any unusual problems while taking this medication.
If you experience a serious side effect, you or your doctor may send a report to the Food and Drug Administration's (FDA) MedWatch Adverse Event Reporting program online (http://www.fda.gov/Safety/MedWatch) or by phone (1-800-332-1088).
What should I do in case of OVERDOSE?
In case of overdose, call the poison control helpline at 1-800-222-1222. Information is also available online at http://www.poisonhelp.org/help. If the victim has collapsed, had a seizure, has trouble breathing, or can't be awakened, immediately call emergency services at 911.
What should I know about STORAGE and DISPOSAL of this medication?
Keep this medication in the container it came in, tightly closed, and out of reach of children. Store it at room temperature and away from excess heat and moisture (not in the bathroom).
Dispose of unneeded medications in a way so that pets, children, and other people cannot take them. Do not flush this medication down the toilet. Use a medicine take-back program. Talk to your pharmacist about take-back programs in your community. Visit the FDA's Safe Disposal of Medicines website http://goo.gl/c4Rm4p for more information.
Keep all medication out of sight and reach of children as many containers are not child-resistant. Always lock safety caps. Place the medication in a safe location - one that is up and away and out of their sight and reach. http://www.upandaway.org
What OTHER INFORMATION should I know?
Keep all appointments with your doctor and the laboratory. Your doctor will order certain lab tests to check your response to thyroid.
Before having any laboratory test, tell your doctor and the laboratory personnel that you are taking thyroid.
Thyroid tablets may have a strong odor. This does not mean that the medication is spoiled or that it cannot be used.
Learn the brand name and generic name of your medication. Check your medication each time you have your prescription refilled or receive a new prescription. Do not switch brands without talking to your doctor or pharmacist, as each brand of thyroid contains a slightly different amount of medication.
Do not let anyone else take your medication. Ask your pharmacist any questions you have about refilling your prescription.
Keep a written list of all of the prescription and nonprescription (over-the-counter) medicines, vitamins, minerals, and dietary supplements you are taking. Bring this list with you each time you visit a doctor or if you are admitted to the hospital. You should carry the list with you in case of emergencies.
This report on medications is for your information only, and is not considered individual patient advice. Because of the changing nature of drug information, please consult your physician or pharmacist about specific clinical use.
The American Society of Health-System Pharmacists, Inc. represents that the information provided hereunder was formulated with a reasonable standard of care, and in conformity with professional standards in the field. The American Society of Health-System Pharmacists, Inc. makes no representations or warranties, express or implied, including, but not limited to, any implied warranty of merchantability and/or fitness for a particular purpose, with respect to such information and specifically disclaims all such warranties. Users are advised that decisions regarding drug therapy are complex medical decisions requiring the independent, informed decision of an appropriate health care professional, and the information is provided for informational purposes only. The entire monograph for a drug should be reviewed for a thorough understanding of the drug's actions, uses and side effects. The American Society of Health-System Pharmacists, Inc. does not endorse or recommend the use of any drug. The information is not a substitute for medical care.
AHFS® Patient Medication Information™ Copyright, 2025. The American Society of Health-System Pharmacists®, 4500 East-West Highway, Suite 900, Bethesda, Maryland. All Rights Reserved. Duplication for commercial use must be authorized by ASHP.
Selected Revisions: September 15, 2025.