Can a 15-Day course of paxlovid ease long COVID?

NCT ID NCT05576662

What the study statuses mean

This study's is highlighted.

Recruitment status, easiest to join first

Recruiting now
This trial is taking on new participants right now.
Not yet recruiting
Registered, but not yet taking participants.
By invitation only
Not open to general applications. Only people the study team invites can take part.
Paused
Paused for now. It may or may not start again.
Ongoing
Running, but no longer taking on new participants.
Completed This study
The trial has finished. Results may not be published yet.
Stopped early
Stopped early, before it reached the end. That can be for many reasons, including safety.
Cancelled
Cancelled before anyone took part.

Expanded access (not trials)

Expanded access
Not a trial. This treatment can be requested outside a study, case by case, for people who qualify.
Expanded access (paused)
Not a trial. The treatment can normally be requested outside a study, but is unavailable right now.
Expanded access (ended)
Not a trial. The treatment could once be requested outside a study, but no longer can.
Approved
The treatment has been approved, so it is available normally rather than through this programme.

When the status isn't known

Details not published
The full record has not been published yet, so there is little to show here.
Status unknown
This status has not been confirmed recently, so it may be out of date.

First seen Jun 26, 2026 ยท Last updated Jun 26, 2026

Summary

This study tested whether taking Paxlovid for 15 days can reduce severe Long COVID symptoms like fatigue, brain fog, and shortness of breath. 168 adults with persistent symptoms after COVID-19 took either the drug or a placebo. Researchers tracked symptom severity over 15 weeks to see if the treatment helped.

What this could mean

Our plain-language read of the trial. This is informational only, not medical advice or a prediction.

Active substance
Paxlovid (nirmatrelvir and ritonavir)
What this could lead to
If it works, this could point toward a treatment for Long COVID symptoms.
What could go wrong
This is a small, early-phase pilot trial, so results may not apply to everyone. The drug may not significantly reduce symptoms, and side effects are possible.

This is an AI summary of the original study and may miss details. Read our disclaimer.

Study facts

What this study's own registry entry says, in plain language.

Phase

Phase 2

Tests whether the treatment actually works, and watches for side effects, in a larger group.

Participants

168 people

The number who actually took part.

Started

Nov 2022

Finished

Sep 2023

Lead sponsor

Other sponsor

The registry's catch-all category, for sponsors it does not file as a company, a government agency, or a research network.

Who can take part

This study's own entry requirements. Only the study team can say for certain whether you qualify.

Ages

18 years and older

Sex

Anyone

Healthy volunteers

Not accepted

This study is not open to healthy volunteers. The entry requirements below say who it is open to.

Show the full entry requirements

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: * Normal or near-normal kidney function * History of confirmed COVID-19 infection that preceded the post-COVID symptoms * Post-COVID-19 symptoms persisting greater than three months * At least 2 post-COVID symptoms of moderate or severe intensity (fatigue, brain fog, shortness of breath, body aches, gastrointestinal symptoms, or cardiovascular symptoms) * Willing to report all vaccinations * Women of childbearing potential or men whose partners may become pregnant must use acceptable method of contraception during the treatment period and for 28 days after the last dose of the study drug * Willing and able to adhere to study procedures and available for the duration of the study Exclusion Criteria: * Suspected or confirmed pregnancy or breastfeeding * Severe liver disease * Prior use of study drug or other COVID treatment within 30 days * Hypersensitivity or other contraindication to any components of the study drug * Current or expected use of any medication dependent on or inducer of CYP3A4 * Current or expected use of supplements or herbs (unless medically necessary) that cannot be temporarily held (period as determined necessary by investigators) * HIV infection with viral load \>50 copies/ml * Suspected or confirmed active COVID infection within 30 days * History of COVID vaccine within 28 days prior to enrollment, or other vaccine (influenza, shingles, etc.) within 14 days of enrollment, or planned use of any vaccine until the primary endpoint has been met (10 weeks) * Other medical condition(s) or concomitant therapy that would compromise participant's safety or compliance with the study protocol or significantly confound interpretation of study results, as determined by study investigators * Current enrollment in, or discontinuation within the last 30 days from, a clinical trial involving any investigational drug or device * Inability to provide informed consent * Currently hospitalized

Get updates

Get notified about this study

Sign up to get updates when this study changes or when new studies for Long COVID are added.

Our safety recommendation!

By submitting, you agree to our Terms of use

Conditions

The condition(s) this trial relates to.

As listed by the trial registrant

The condition terms exactly as the trial's registrant entered them.

Contacts and locations

Locations

  • Stanford University

    Stanford, California, 94305, United States

More trials for these conditions

Other studies related to the condition(s) this trial covers.