Can a 15-Day course of paxlovid ease long COVID?
NCT ID NCT05576662
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
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Nov 2022
- Finished
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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 Hide 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
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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.
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