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Peanut allergen extract

Generic name: peanut allergen extract [ PEE-nut-AL-er-jen-EX-tract ]
Brand name: Palforzia
Dosage forms: oral capsule (0.5 mg-1 mg; 12 mg daily-dose; 120 mg daily-dose; 160 mg daily-dose; 20 mg daily-dose; 200 mg daily-dose; 240 mg daily-dose; 3 mg daily-dose; 40 mg daily-dose; 6 mg daily-dose; 80 mg daily-dose); oral powder (300 mg)
Drug class: Allergenics

Medically reviewed by on Feb 9, 2022. Written by Cerner Multum.

What is peanut allergen extract?

Peanut allergen extract is used to help reduce the severity of an allergic reaction (including anaphylaxis) when you are accidentally exposed to peanuts. peanut allergen extract will not treat an allergic reaction that has already begun.

Peanut allergen extract is for use in adults and children at least 4 years old who have been diagnosed with an actual peanut allergy. Peanut allergen extract will not affect allergic reactions to other foods. Always seek emergency medical attention if you have an allergic reaction.

Peanut allergen extract is available only under a special program. You must be registered in the program and understand the risks and benefits of this medicine.

Peanut allergen extract may also be used for purposes not listed in this medication guide.


You should not use this medicine if you have uncontrolled asthma, or problems with your esophagus or digestive tract due to increased eosinophils (a type of white blood cell).

Peanut allergen extract can cause a severe or life-threatening allergic reaction. Your doctor may prescribe epinephrine injection to keep on hand in case you have an allergic reaction.

Call your doctor or get emergency medical help if you have an allergic reaction, even if you have used epinephrine to treat it.

Before taking this medicine

You should not use peanut allergen extract if you have:

  • untreated or uncontrolled asthma; or

  • problems with your esophagus or digestive tract that are caused by higher than normal levels of eosinophils (a type of white blood cell).

You may not be able to use peanut allergen extract if:

  • you are unable to give yourself an epinephrine injection in the case of an allergic reaction; or

  • an allergic reaction would be life-threatening to you because of a medical condition you have or a medicine you use.

Tell your doctor if you have ever had:

  • asthma; or

  • any disease related to increased eosinophils.

Tell your doctor if you are pregnant or breastfeeding.

How should I take peanut allergen extract?

Follow all directions on your prescription label and read all medication guides or instruction sheets. Your doctor may occasionally change your dose. Use the medicine exactly as directed.

When you start using peanut allergen extract (and any time your dose is increased) you will receive your first dose in a hospital or clinic setting. Your breathing, blood pressure, oxygen levels, and other vital signs will be watched closely for at least 60 minutes after your dose.

Your dose may need to be postponed if you are not feeling well before starting this treatment.

Do not swallow a capsule whole or inhale the powder medicine. Open the capsule or powder packet and sprinkle the medicine into a spoonful of applesauce, yogurt, or pudding (do not mix with liquid). Stir well and swallow the mixture right away without chewing. Do not save it for later use.

You may need to use up to 6 capsules to get the correct dose. Follow your doctor's dosing instructions very carefully.

Wash your hands after handling a capsule or powder packet.

You may be more likely to have an allergic reaction:

  • if you have uncontrolled asthma;

  • if you are sick with a virus;

  • during your menstrual period;

  • during vigorous exercise or exposure to hot water;

  • if you are not getting enough sleep;

  • if you are not getting enough to eat; or

  • if you are taking an NSAID (nonsteroidal anti-inflammatory drug).

The timing of your doses may need to be adjusted to avoid using peanut allergen extract while any of the above conditions exists.

Store peanut allergen extract in the original packaging in a refrigerator, do not freeze.

You must keep injectable epinephrine with you at all times while you are using peanut allergen extract. Read and carefully follow any Instructions for Use provided with your epinephrine. Ask your doctor or pharmacist if you don't understand all instructions.

What happens if I miss a dose?

Call your doctor for instructions if you miss a dose.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

Overdose symptoms may include trouble swallowing, trouble breathing, changes in your voice, or a feeling of fullness in your throat.

What should I avoid while taking peanut allergen extract?

In addition to taking peanut allergen extract, you should avoid peanuts in your diet.

Peanut allergen extract side effects

Peanut allergen extract can cause a severe or life-threatening allergic reaction. Stop using this medicine and get emergency medical help if you have signs of an allergic reaction:

  • chest discomfort, wheezing, trouble breathing;

  • tightness in your throat;

  • trouble speaking or swallowing;

  • swelling of your face, lips, eyes, or tongue;

  • itchy, raised bumps on your skin;

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

  • severe stomach pain, vomiting, or diarrhea; or

  • a light-headed feeling, like you might pass out.

Your doctor may prescribe epinephrine injection to keep on hand in case you have an allergic reaction. Get emergency medical help if you have an allergic reaction, even if you have used epinephrine to treat it.

Also call your doctor at once if you have symptoms of inflammation in your stomach or esophagus:

  • vomiting undigested food;

  • trouble swallowing (food getting stuck in throat);

  • feeling sick; or

  • burning in your mouth, throat, or chest.

Common side effects of peanut allergen extract may include:

  • itching or burning in your mouth;

  • cough, wheezing, trouble breathing;

  • tightness or irritation in your throat;

  • rash, itchy skin;

  • itching in or around your ear;

  • runny nose, sneezing; or

  • stomach pain, nausea, vomiting.

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.

What other drugs will affect peanut allergen extract?

Other drugs may affect peanut allergen extract, including prescription and over-the-counter medicines, vitamins, and herbal products. Tell your doctor about all your current medicines and any medicine you start or stop using.

Further information

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.