Photo of woman pharmacist taking a medicine from the shelf, wearing lab coat during work in a modern drugstore with various pharmaceutical products.

Updated January 5, 2024. This post will be updated when new information becomes available.

Two antiviral pills are available to treat COVID-19. One is fully approved by the U.S. Food and Drug Administration (FDA) – Paxlovid. The FDA fully approved Paxlovid in May 2023 for adults who are at risk for severe COVID-19 illness. It continues to be approved under an Emergency Use Authorization (EUA) for children ages 12-18 at risk for severe illness.

The antiviral pills are a major step forward in the fight against the COVID-19 pandemic. They help reduce the risk of hospitalization and death. Prior to the pills, most COVID-19 treatments were administered intravenously and usually in a hospital. Monoclonal antibody treatments are effective in treating COVID-19, but they also require monitoring by healthcare providers.

What antiviral pills for COVID-19 are currently available?

Two COVID-19 antiviral pills are available, one from Pfizer and one from Merck/Ridgeback Biotherapeutics:

  • Paxlovid – fully approved by FDA for adults, it is a combination of nirmatrelvir and the HIV/AIDS drug ritonavir (Pfizer).
  • Lagevrio (molnupiravir) – approved under an EUA (Merck/Ridgeback Biotherapeutics).

The antiviral pills prevent onset of severe symptoms from COVID-19. Clinical trials showed both medications were able to help prevent hospitalization and death from COVID-19 infection.

The therapy can be taken at home, making this antiviral treatment ideal for many patients.

Who should get a COVID-19 antiviral pill?

Paxlovid and Lagevrio are approved for people with mild or moderate COVID-19 who are at risk of becoming seriously ill. These include people with chronic diseases such as:

  • asthma
  • COPD
  • lung diseases
  • heart disease
  • diabetes
  • a compromised immune system

Paxlovid is authorized for patients who are 12 years of age and older. Lagevrio is approved only for adults 18 years of age or older. Lagevrio is not recommended for use by pregnant women.

People with asthma or COPD should talk with their doctor about using their asthma medications while taking Paxlovid. Long-acting beta-agonists (LABA) taken with Paxlovid may cause cardiac risks. Salmeterol, in particular, may need to be withheld during Paxlovid treatment. Certain inhaled corticosteroids taken with Paxlovid may put patients at increased risk for Cushing’s syndrome and adrenal suppression.

In most cases, the benefits of a short course of Paxlovid to treat COVID-19 will outweigh the potential risks. It may be more dangerous to stop taking asthma medication even for a short period of time. That’s why it’s important to talk with your doctor about the risks and any possible alternative medications.

Learn more about Paxlovid from FDA.

How can Americans get a COVID-19 antiviral pill?

If you test positive for COVID-19, you may ask, “How can I get access to the COVID pill?” Discuss this treatment option with your doctor to find out if a COVID-19 pill is right for you.

Doctors can prescribe Paxlovid and Lagevrio to people with a positive COVID-19 test. They can also provide prescriptions to people diagnosed with COVID-19 based on symptoms or recent exposures to others with COVID-19.

While it’s recommended you see your doctor for Paxlovid, FDA has also authorized state-licensed pharmacists to prescribe Paxlovid with certain limitations. Patients should provide the following information to the pharmacist:

  • electronic or printed health records less than 12 months old;
  • a list of all medications you are taking so the pharmacist can screen for drugs that may interact with Paxlovid.

Remember, Paxlovid is not for everyone. Doctors prescribe Paxlovid for people who are at high risk for severe disease. It may help treat mild symptoms but only in people who may progress to severe disease. In fact, a recent Pfizer study indicated Paxlovid may not benefit patients who are low-risk for severe illness and are vaccinated.

Pharmacists should refer patients to doctors for special considerations. These considerations may include possible drug interactions with Paxlovid.

How much and how often should you take COVID-19 antiviral drugs?

Both Paxlovid and Lagevrio should be taken within five days of experiencing COVID-19 symptoms.

Paxlovid is given at a dose of 300 mg (two 150 mg tablets) of nirmatrelvir with one 100 mg tablet of ritonavir, twice-daily for five days. It is a total of three tablets twice a day.

Lagevrio is given at a dose of 800 mg (four 200 mg tablets) every 12 hours for five days. This is a total of four pills twice a day.

Concept photo of closeup of pills, the Covid Pill is highlighted and the rest are in the dark.

How does the COVID pill work?

Both the Paxlovid and Lagevrio pills work by limiting the ability of the virus to replicate.

Paxlovid is a protease inhibitor. It is a combination of two medications: nirmatrelvir, which stops the virus from replicating, and ritonavir, which stops nirmatrelvir from breaking down. Lagevrio is a type of nucleoside analog. Both of these medications have previously been valuable in the fight against HIV/AIDS.

In clinical studies, Paxlovid and Lagevrio have both shown the ability to reduce the risk of hospitalization and death in COVID-19 patients. The medications were taken within three days of symptom onset.

According to the National Institutes of Health (NIH), Lagevrio has been shown to be effective against all RNA (ribonucleic acid) viruses while Paxlovid “has demonstrated antiviral activity against all coronaviruses that are known to infect humans.”

Do the COVID pills work for the Omicron variants?

Both Paxlovid and Lagevrio are effective treatments to those infected with the Omicron variants.

How much is the pill for COVID-19?

During the first couple years of the pandemic, Paxlovid and Lagevrio were free. The federal government purchased large supplies of both COVID medications and distributed them to states so they could be free to the public.

In 2023, Paxlovid and Lagevrio transitioned to the private marketplace. This means they are no longer free from the federal government.

Most people who have private health insurance should be able to obtain the medications for free or at low cost. Check with your health insurance provider to see if it will be covered. For Paxlovid, people can enroll in a Co-Pay Savings Program.

People on Medicare or Medicaid can still obtain Paxlovid at no cost through a patient assistance program from Pfizer. So can people who get healthcare through the Department of Veterans Affairs and the Indian Health Service.

What about people with no health insurance? Pfizer has said Paxlovid will continue to be free for people without health insurance through at least 2024. Merck has a patient assistance program available as well.

The full cost for Paxlovid out of pocket is high – $1,390 for the five-day treatment course. The full cost for Lagevrio out of pocket is not yet available.

Concept photo of scientist doing medical research on the Covid Pill

What are the COVID pill ingredients?

Pfizer’s Paxlovid is a combination of the two active ingredients, nirmatrelvir and ritonavir. Additional inactive ingredients include:

  • colloidal silicon dioxide
  • croscarmellose sodium
  • lactose monohydrate
  • microcrystalline cellulose
  • sodium stearyl fumarate
  • hydroxypropyl methylcellulose
  • iron oxide red
  • polyethylene glycol
  • titanium dioxide
  • anhydrous dibasic calcium phosphate
  • copovidone
  • sorbitan monolaurate
  • hydroxypropyl cellulose
  • hypromellose
  • polyethylene glycol 40
  • polyethylene glycol 3350
  • polysorbate 80
  • talc

The Lagevrio active ingredient is molnupiravir, with additional ingredients as part of the capsule and printing:

  • croscarmellose sodium
  • hydroxypropyl cellulose
  • magnesium stearate
  • microcrystalline cellulose
  • Hypromellose
  • titanium dioxide
  • red iron oxide
  • butyl alcohol
  • dehydrated alcohol
  • isopropyl alcohol
  • potassium hydroxide
  • propylene glycol
  • purified water
  • shellac
  • strong ammonia solution

If you are allergic to any of the active or inactive ingredients to these medications, make sure to let your doctor know and discuss risks vs. benefits.

Do COVID-19 pills have side effects or allergens?

Medications always have a risk for potential side effects and/or may cause an allergic reaction. That is why it is important to know your allergies. Make sure your healthcare records are updated with your doctors and pharmacy. And be sure to read ingredient lists of medications.

If you are allergic to any of the ingredients of a medicine or vaccine, don’t take it. Instead, talk with your doctor. There may be alternative medicines or vaccines available.

Studies have linked both COVID-19 pills to “COVID rebound.” This is when a COVID-19 patient recovers from illness, but develops symptoms again several days later. However, some people have had COVID rebound even when not taking the pills, suggesting the rebound is not due to the pills alone.

Does Paxlovid have side effects?

According to the FDA patient fact sheet, Paxlovid may cause liver problems, resistance to HIV medications, an altered sense of taste, diarrhea, high blood pressure, and muscle aches. Most side effects are reported as mild.

Does Lagevrio have side effects?

According to the FDA patient fact sheet for Lagevrio, side effects include nausea, dizziness, and diarrhea.

Molnupiravir is not recommended for use by pregnant women as some studies indicate it could impact the development of a fetus. It’s also not recommended for women who are breastfeeding.

In addition, scientists are studying how Lagevrio affects sperm in men and whether it could impact the development of a fetus. It is recommended that sexually active men use a reliable method of birth control while taking Lagevrio and for at least 3 months after the last dose.

Do the COVID-19 antiviral pills interact with other medications and can this lead to a severe reaction?

Both Paxlovid and Lagevrio pills can interact with other medications a person is taking and cause a severe reaction.

The National Institutes of Health has posted a list of medications that may interact with Paxlovid. The list includes salmeterol, which is a long-acting beta2-agonist (LABA) medication used to treat asthma and COPD. Salmeterol taken with Paxlovid may cause cardiac risks.

Salmeterol should not be taken at the same time as Paxlovid. Alternatives to treat asthma include vilanterol, formoterol and albuterol. Doctors should prescribe these medications instead of salmeterol while their patient is taking Paxlovid, and for another three days afterward.

Paxlovid can also interact with medications such as statins, blood thinners and some antidepressants.

It’s important to tell your doctor all of the medications you’re taking. Ask whether any of them will interact with the COVID-19 pill. The doctor may withhold the COVID-19 pill and/or prescribe an alternative COVID-19 therapy.

What’s the difference between Paxlovid and Lagevrio?

Both Paxlovid and Lagevrio are classified as antiviral medications.

Paxlovid is a protease inhibitor. Protease is an enzyme which works by chopping up viral proteins into smaller portions so they can spread easily. Protease inhibitors work by poisoning the protease so the viral protein chain remains long and cannot effectively replicate.

Lagevrio is a nucleoside analog and works by inserting errors into the virus’s genetic code. This interferes with the virus’s ability to replicate itself.

The common thread with both medications is they limit the ability of the COVID-19 virus to replicate. Viruses replicate very quickly at the beginning of an illness, so that is why it is important for these pills to be taken as early as possible from the onset of symptoms. The longer the virus has to replicate, the more challenge to reducing symptoms and risk.

Can I take a COVID-19 pill instead of a vaccine?

The COVID-19 antiviral pill is not a replacement for vaccination. The pill treats COVID-19 and prevents severe symptoms in people already diagnosed with the condition and who are at high risk for severe illness. The COVID-19 vaccines can help prevent infection and reduce the risk of severe illness but they do not treat COVID-19 after diagnosis.

Consider the antiviral pills as another tool in the toolbox to treat COVID-19.

Does the COVID-19 pills contain ivermectin?

You may be asking, “Is this the same COVID-19 pill that’s also for horses?” The answer is no. The “horse pill” is ivermectin. Ivermectin is an antiparasitic approved to treat some tropical diseases in humans. It is also used to deworm livestock, including horses. Ivermectin is not approved to treat COVID-19.

Paxlovid and Lagevrio do not contain ivermectin. They have different chemical structures and compositions.

Reviewed by
Purvi Parikh, MD, FACAAI is an adult and pediatric allergist and immunologist at Allergy and Asthma Associates of Murray Hill in New York City. She is on faculty as Clinical Assistant Professor in both departments of Medicine and Pediatrics at New York University School of Medicine.