What is remdesivir used for? An in-depth look at the COVID-19 antiviral

October 7, 2025 •

3 min read

Remdesivir (sold as Veklury) was the first antiviral medication to receive FDA approval for the treatment of COVID-19 in October 2020. To understand its purpose and effectiveness, it's essential to know what is remdesivir used for and the clinical evidence supporting its use.

Quick Summary

Remdesivir is an antiviral drug for treating COVID-19 in hospitalized patients and high-risk, non-hospitalized patients. It works by inhibiting the SARS-CoV-2 virus's ability to replicate, helping to reduce recovery time and disease progression.

Key Points

Antiviral for COVID-19: Remdesivir (Veklury) is an FDA-approved antiviral treatment for COVID-19 in both hospitalized and non-hospitalized high-risk patients.
Mechanism of Action: It works by inhibiting the viral RNA-dependent RNA polymerase (RdRp), which disrupts the virus's ability to replicate within cells.
Hospitalized Patients: For hospitalized patients, a typical treatment course is 5 days, extendable to 10 days in certain situations.
High-Risk Outpatients: For non-hospitalized patients at high risk for severe illness, a 3-day IV infusion course is administered within 7 days of symptom onset.
Intravenous Administration: Remdesivir is given as an IV infusion in a clinical setting, unlike oral medications like Paxlovid.
Specific Patient Populations: It is a key treatment for immunocompromised patients and young children, sometimes preferred over other antivirals due to fewer drug interactions.
Common Side Effects: Common side effects include nausea and elevated liver enzymes, with more serious infusion-related reactions also possible.

What is Remdesivir (Veklury)?

Remdesivir is a broad-spectrum antiviral medication initially developed for hepatitis C and Ebola, but it is primarily used for treating COVID-19. The drug is a nucleotide analog prodrug that is converted into an active form within the body to fight the virus. It is administered via intravenous (IV) infusion in a clinical setting.

How Remdesivir Works to Stop the Virus

Remdesivir interferes with the SARS-CoV-2 virus's ability to replicate by targeting the viral enzyme RNA-dependent RNA polymerase (RdRp). The active form of remdesivir is incorporated into the new viral RNA strand, causing a delayed stop in the replication process and preventing the production of new viruses. This action helps reduce the viral load.

Remdesivir's Approved Uses for COVID-19

Remdesivir (Veklury) is approved for treating COVID-19 in adult and pediatric patients. Its use varies depending on whether the patient is hospitalized and their risk factors.

Hospitalized Patients

Remdesivir is a recommended treatment for hospitalized patients to improve recovery. A typical course is a 5-day IV treatment, which can be extended up to 10 days if needed. For severe cases, a 10-day course is recommended, often with dexamethasone.

Non-Hospitalized High-Risk Patients

Remdesivir is also used for non-hospitalized patients at high risk for severe COVID-19. These patients must have mild-to-moderate COVID-19 and at least one risk factor for severe disease. Treatment should start within 7 days of symptom onset for maximum effectiveness, and the course is a 3-day series of IV infusions. Studies show this can reduce hospitalization or death in high-risk individuals.

Potential Side Effects of Remdesivir

Remdesivir can cause side effects, and patients are monitored during administration. Common side effects include nausea, changes in liver enzymes, infusion site reactions, and headache. Serious side effects like infusion-related reactions, liver injury, and allergic reactions are possible.

Comparison with Other COVID-19 Treatments

Remdesivir is an IV treatment, unlike oral options such as Paxlovid. The choice depends on the patient's needs and clinical guidelines.


Feature	Remdesivir (Veklury)	Nirmatrelvir-Ritonavir (Paxlovid)
Administration	Intravenous (IV) infusion	Oral pills
Setting	Hospital or clinical setting	At home, prescribed by a doctor
Duration	3 days (outpatient) or 5-10 days (hospitalized)	5 days
Timing	Administered within 7 days of symptom onset (outpatient)	Administered within 5 days of symptom onset
Drug Interactions	Fewer significant interactions compared to Paxlovid	Extensive potential drug-drug interactions
Patient Population	High-risk non-hospitalized, hospitalized adults and children	High-risk non-hospitalized adults and children
Efficacy	Significantly reduces risk of hospitalization or death when given early	Also shows high efficacy in reducing hospitalization or death

Who Is Remdesivir for? A Look at Specific Patient Populations

Remdesivir is particularly beneficial for certain groups, including immunocompromised individuals where it has shown efficacy in reducing mortality. It's a preferred first-line antiviral for some, like transplant patients, due to fewer drug interactions. It is approved for pediatric patients as young as 28 days and weighing at least 3 kg, if they are hospitalized or at high risk. Remdesivir can also be used in patients with severe renal impairment, including those on dialysis, without dose adjustment.

Conclusion: The Role of Remdesivir in COVID-19 Treatment

Remdesivir is a key treatment for COVID-19, especially for hospitalized and high-risk patients. Its IV administration and the need for early use are defining characteristics. Despite the availability of oral antivirals, remdesivir remains crucial, particularly for patients with contraindications to other treatments. Updated guidelines continue to refine its optimal use in managing COVID-19.

Visit the NIH COVID-19 Treatment Guidelines for more information

Frequently Asked Questions

Remdesivir is marketed under the brand name Veklury.

Remdesivir is approved for adults and pediatric patients weighing at least 3 kg who are hospitalized with COVID-19 or who are high-risk outpatients with mild-to-moderate COVID-19.

Remdesivir is given as an intravenous (IV) infusion, which must be administered by a healthcare professional in a hospital or clinical setting.

Common side effects include nausea and increases in liver enzyme levels. Infusion-related reactions, like flushing and shivering, have also been reported.

Yes, a 3-day course is authorized for non-hospitalized patients with mild-to-moderate COVID-19 who are at high risk for progressing to severe disease.

In vitro studies have shown that remdesivir retains its antiviral activity against recent Omicron subvariants and other emerging variants.

The main difference is the administration method; remdesivir is an IV infusion, while Paxlovid is an oral pill. While both are highly effective in reducing severe COVID-19 outcomes in high-risk patients, Paxlovid has more significant drug-drug interactions.

Early administration is crucial because remdesivir targets the virus's replication process, which is most active in the early stages of the illness. This helps prevent the progression to severe disease.