Authorized for FDA Emergency Use only

(casirivimab and imdevimab)

Authorized Use

REGEN-COV® (casirivimab and imdevimab) is an investigational medicine used in adults and adolescents (12 years of age and older who weigh at least 88 pounds (40kg)) who are at high risk for severe COVID-19, including hospitalization or death for:

  • treatment of mild to moderate symptoms of COVID-19
  • post-exposure prophylaxis of COVID-19 in persons who are:
    • not fully vaccinated against COVID-19 (Individuals are considered to be fully vaccinated 2 weeks after their second vaccine dose in a 2-dose series or 2 weeks after a single-dose vaccine) or,
    • are not expected to build up enough of an immune response to the complete COVID-19 vaccination (for example, someone with immunocompromising conditions), and
      • have been exposed to someone who is infected with SARS-CoV-2. Close contact with someone who is infected with SARS-CoV-2 is defined as being within 6 feet for a total of 15 minutes or more, providing care at home to someone who is sick, having direct physical contact with the person, sharing eating or drinking utensils, or being exposed to respiratory droplets from an infected person, or
      • someone who is at high risk of being exposed to someone who is infected with SARS-CoV-2 because of occurrence of SARS-CoV-2 infection in other individuals in the same institutional setting (for example, nursing homes, prisons)

REGEN-COV is investigational because it is still being studied. There is limited information known about the safety and effectiveness of using REGEN-COV to treat people with COVID-19 or to prevent COVID-19 in people who are at high risk of being exposed to someone who is infected with SARS-CoV-2. REGEN-COV is not authorized for pre-exposure prophylaxis for prevention of COVID-19.

  • REGEN-COV has not been approved, but has been authorized for emergency use by FDA
  • This use is authorized only for the duration of the declaration that circumstances exist justifying the authorization of the emergency use under section 564(b)(1) of the Act, 21 U.S.C. § 360bbb-3(b)(1), unless the authorization is terminated or revoked sooner

Do not take REGEN-COV if you have had a severe allergic reaction to REGEN-COV

Note: Due to the large reduction of pseudotyped VLP neutralization activity against spike protein from the B.1.1.529/BA.1 (Omicron; South Africa origin) variant, it is unlikely that casirivimab and imdevimab together will be active against this variant.

Important Safety Information

Important possible side effects of REGEN-COV (casirivimab and imdevimab)

  • Allergic reactions: Allergic reactions can happen during and after infusion with REGEN-COV. Tell your healthcare provider right away if you get any of the following signs and symptoms of allergic reactions: fever, chills, nausea, headache, shortness of breath, low or high blood pressure, rapid or slow heart rate, chest discomfort or pain, weakness, confusion, feeling tired, wheezing, swelling of your lips, face, or throat, rash including hives, itching, muscle aches, feeling faint, dizziness and sweating. These reactions may be severe or life threatening.
  • Worsening symptoms after treatment: You may experience new or worsening symptoms after infusion, including fever, difficulty breathing, rapid or slow heart rate, tiredness, weakness or confusion. If these symptoms occur, contact your healthcare provider or seek immediate medical attention as some of these symptoms have required hospitalization. It is unknown if these symptoms are related to treatment or are due to the progression of COVID-19.

The side effects of getting any medicine by vein may include brief pain, bleeding, bruising of the skin, soreness, swelling, and possible infection at the infusion site. The side effects of getting any medicine by subcutaneous injection may include pain, bruising of the skin, soreness, swelling, and possible infection at the injection site.

These are not all the possible side effects of REGEN-COV. Not a lot of people have been given REGEN-COV. Serious and unexpected side effects may happen. REGEN-COV is still being studied, so it is possible that all of the risks are not known at this time.

It is possible that REGEN-COV could interfere with your body’s own ability to fight off a future infection of SARS-CoV-2. Similarly, REGEN-COV may reduce your body’s immune response to a vaccine for SARS-CoV-2. Specific studies have not been conducted to address these possible risks. Talk to your healthcare provider if you have any questions.

Pregnancy and breastfeeding

There is limited experience treating pregnant women or breastfeeding mothers with REGEN-COV. For a mother and unborn baby, the benefit of receiving REGEN-COV may be greater than the risk of using the product. If you are pregnant or breastfeeding, discuss your options and specific situation with your healthcare provider.

Tell your healthcare provider about all of your medical conditions, including if you:

  • Have any allergies
  • Have had a severe allergic reaction including anaphylaxis to REGEN-COV previously
  • Have received a COVID-19 vaccine
  • Have any serious illnesses
  • Are pregnant or plan to become pregnant
  • Are breastfeeding or plan to breastfeed
  • Are taking any medications (prescriptions, over-the-counter drugs, vitamins, and herbal products)

Please see the Fact Sheet for Patients, Parents and Caregivers for more information.

The product information in this site is intended only for residents of the U.S. The products discussed herein may have different product labeling in different countries.

You are encouraged to report negative side effects of prescription drugs to the FDA Visit or call 1-800-FDA-1088.

More information available at

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