Skip to Content

NP Thyroid

Generic Name: Thyroid, Desiccated (THYE roid DES i kay tid)
Brand Name: Armour Thyroid, Nature-Throid, NP Thyroid, Westhroid, WP Thyroid


  • Do not use NP Thyroid (thyroid, desiccated) to treat obesity or for weight loss. Very bad and sometimes deadly side effects may happen with NP Thyroid (thyroid, desiccated) if it is taken in large doses or with other drugs for weight loss. Talk with the doctor.

Uses of NP Thyroid:

  • It is used to add thyroid hormone to the body.
  • It is used to treat or prevent an enlarged thyroid.
  • It is used to manage thyroid cancer.
  • It may be given to you for other reasons. Talk with the doctor.

What do I need to tell my doctor BEFORE I take NP Thyroid?

  • If you have an allergy to thyroid drugs or any other part of NP Thyroid (thyroid, desiccated).
  • If you are allergic to NP Thyroid (thyroid, desiccated); any part of NP Thyroid (thyroid, desiccated); or any other drugs, foods, or substances. Tell your doctor about the allergy and what signs you had.
  • If you have any of these health problems: Overactive thyroid gland or weak adrenal gland.

This is not a list of all drugs or health problems that interact with NP Thyroid (thyroid, desiccated).

Tell your doctor and pharmacist about all of your drugs (prescription or OTC, natural products, vitamins) and health problems. You must check to make sure that it is safe for you to take NP Thyroid (thyroid, desiccated) with all of your drugs and health problems. Do not start, stop, or change the dose of any drug without checking with your doctor.

What are some things I need to know or do while I take NP Thyroid?

  • Tell all of your health care providers that you take NP Thyroid (thyroid, desiccated). This includes your doctors, nurses, pharmacists, and dentists.
  • Do not run out of NP Thyroid (thyroid, desiccated).
  • It may take several weeks to see the full effects.
  • If you have high blood sugar (diabetes), you will need to watch your blood sugar closely.
  • Have blood work checked as you have been told by the doctor. Talk with the doctor.
  • This medicine is made from pork (pig) thyroid tissue. There is a very small risk of getting a viral disease from NP Thyroid (thyroid, desiccated). No cases have been reported. If you have questions, talk with the doctor.
  • If you are 65 or older, use NP Thyroid (thyroid, desiccated) with care. You could have more side effects.
  • Tell your doctor if you are pregnant, plan on getting pregnant, or are breast-feeding. You will need to talk about the benefits and risks to you and the baby.

How is this medicine (NP Thyroid) best taken?

Use NP Thyroid (thyroid, desiccated) as ordered by your doctor. Read all information given to you. Follow all instructions closely.

  • It is best to take NP Thyroid (thyroid, desiccated) on an empty stomach.
  • There is more than 1 brand of NP Thyroid (thyroid, desiccated). One brand cannot safely be used for the other. The doctor will tell you about any needed change.
  • Do not take colesevelam, colestipol, or cholestyramine within 4 hours of NP Thyroid (thyroid, desiccated).
  • Some foods like soybean flour (infant formula) may change how NP Thyroid (thyroid, desiccated) works in your body. Talk with your doctor.
  • Take NP Thyroid (thyroid, desiccated) at the same time of day.
  • Keep taking NP Thyroid (thyroid, desiccated) as you have been told by your doctor or other health care provider, even if you feel well.

What do I do if I miss a dose?

  • Take a missed dose as soon as you think about it.
  • If it is close to the time for your next dose, skip the missed dose and go back to your normal time.
  • Do not take 2 doses at the same time or extra doses.

What are some side effects that I need to call my doctor about right away?

WARNING/CAUTION: Even though it may be rare, some people may have very bad and sometimes deadly side effects when taking a drug. Tell your doctor or get medical help right away if you have any of the following signs or symptoms that may be related to a very bad side effect:

  • Signs of an allergic reaction, like rash; hives; itching; red, swollen, blistered, or peeling skin with or without fever; wheezing; tightness in the chest or throat; trouble breathing, swallowing, or talking; unusual hoarseness; or swelling of the mouth, face, lips, tongue, or throat.
  • Chest pain or pressure.
  • Fast or abnormal heartbeat.
  • Shortness of breath, a big weight gain, or swelling in the arms or legs.
  • Lump on the neck.
  • Headache.
  • Feeling nervous and excitable.
  • Shakiness.
  • Trouble sleeping.
  • Bothered by heat.
  • Sweating a lot.
  • Feeling more or less hungry.
  • A change in weight without trying.
  • Diarrhea.
  • Stomach cramps.
  • Throwing up.
  • Feeling irritable.
  • Fever.
  • Leg cramps.
  • Muscle weakness.
  • Period (menstrual) changes.

What are some other side effects of NP Thyroid?

All drugs may cause side effects. However, many people have no side effects or only have minor side effects. Call your doctor or get medical help if any of these side effects or any other side effects bother you or do not go away:

  • Hair loss may happen in some people in the first few months of using NP Thyroid (thyroid, desiccated). This most often goes back to normal.

These are not all of the side effects that may occur. If you have questions about side effects, call your doctor. Call your doctor for medical advice about side effects.

You may report side effects to the FDA at 1-800-332-1088. You may also report side effects at

If OVERDOSE is suspected:

If you think there has been an overdose, call your poison control center or get medical care right away. Be ready to tell or show what was taken, how much, and when it happened.

How do I store and/or throw out NP Thyroid?

  • Store at room temperature.
  • Protect from light.
  • Store in a dry place. Do not store in a bathroom.
  • Keep all drugs in a safe place. Keep all drugs out of the reach of children and pets.
  • Throw away unused or expired drugs. Do not flush down a toilet or pour down a drain unless you are told to do so. Check with your pharmacist if you have questions about the best way to throw out drugs. There may be drug take-back programs in your area.

Consumer information use

  • If your symptoms or health problems do not get better or if they become worse, call your doctor.
  • Do not share your drugs with others and do not take anyone else's drugs.
  • Some drugs may have another patient information leaflet. Check with your pharmacist. If you have any questions about NP Thyroid (thyroid, desiccated), please talk with your doctor, nurse, pharmacist, or other health care provider.
  • If you think there has been an overdose, call your poison control center or get medical care right away. Be ready to tell or show what was taken, how much, and when it happened.

Further information

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