A Fasting Pilot Study for Long COVID

February 10, 2026 updated by: Université de Sherbrooke

A Prospective Pilot Study to Evaluate the Feasibility of Prolonged Fasting for the Treatment of Long COVID Patients

Background Long COVID (LC) is a chronic multisystemic condition which substantially impact the quality of life. Despite the staggering burden of LC, there is still no effective treatment.

Because fasting promotes anti-inflammatory and antioxidant responses, which are involved in the pathophysiology of LC, we hypothesized that it might improve daily functioning and health-related quality of life in patients with LC.

The aim of this single center, one arm, prospective pilot clinical trial will be to assess the feasibility and acceptability of prolonged fasting for LC. The main questions aims to answers are;

  1. Does in-home prolonged fasting (7 days) is feasible and acceptable for patients with LC
  2. Is there a clinical benefit associated with fasting is LC patients

Participants (adults 18 year and older) will be asked to

  1. Fast for 7 days
  2. Have in-person visit at baseline (day 0) and at day 9 for checkups and tests
  3. Answer difference questionnnaires about their perceived health during and after fasting

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Completed

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
25

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Canada
    • Quebec
      • Sherbrooke, Quebec, Canada
        • Centre de recherche du CIUSSSE-CHUS

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Age 18-64 years
  • Diagnosis Long Covid based on WHO criteria (post-acute COVID-19 symptoms persisting ≥12 weeks) and validiated by an experienced cinician
  • Normal body Mass Index (18.5 to 39 kg/m2)
  • Able to communicate in and comprehend English and/or French language
  • Present written / signed declaration of consent
  • Ability to understand the patient information and willingness to sign the consent form
  • Willing to limit physical activity during prolonged fasting

Exclusion Criteria:

  • Current underweight condition (body mass index less than 18.5 kg/m2) or weight loss exceeding 3 kg within the last month or 5 kg within the last three months.
  • Current or history of eating disorder (e.g., anorexia, bulimia).
  • Psychiatric condition that limits understanding of the examination protocol (unable to consent)
  • Participation in another intervention study.
  • Fasting during the last six months
  • Pregnancy or breastfeeding status.
  • Diagnosis of chronic inflammatory bowel diseases, celiac disease or colorectal cancer according to the guidelines of the Canadian Society of Gastroenterology
  • Use of anti-psychotic drugs
  • Start of novel drug therapy for long COVID
  • Contraindication for additional blood draws (e.g. hemoglobin <100)
  • Taking opioid analgesics or undergoing treatment for opioid addiction
  • Opioid dependence or withdrawal syndrome
  • Type 1 or 2 Diabetes, or history of hypoglycemia
  • Active cancer
  • Baseline E+ (Na, K, Mg, phosphate) within normal range
  • Baseline ALT < 60
  • Baseline Hb > 100
  • Baseline INR within normal range
  • Baseline DFG < 50

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Other
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: Fasting arm
Participants will be allowed to continue their regular drug treatment
Other: prolonged fasting
Participants will be fasting for 7 days

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Feasibility and Acceptability
Time Frame: From baseline (day 0) to end of follow up day 30
Retention rates will be used to measure feasibility and response to Likert-like questions for measuring acceptability
From baseline (day 0) to end of follow up day 30

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Mean changes from baseline to one month post-fasting on the SF 36 physical component score questionnaire
Time Frame: From baseline (day 0) to the end of follow up at day 30
The SF 36 questionnaire is a validated scale for assessment and monitoring of patients with LC. The 36-item scale includes 8 subscales : role functioning-physical, body pain, general health, vitality, social functioning, role functioning-emotional, and mental health.
From baseline (day 0) to the end of follow up at day 30

Other Outcome Measures

Other Outcome Measures

For clinical trials, a planned measurement described in the protocol that is used to determine the effect of an intervention/treatment on participants. For observational studies, a measurement or observation that is used to describe patterns of diseases or traits, or associations with exposures, risk factors, or treatment. Types of outcome measures include primary outcome measure and secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Fatigue severity score (FSS)
Time Frame: From baseline (day 0) to end of follow up at day 30
The Fatigue severity scale (FSS) (0-7 score, 7 being worse) is one of the tool to assess the severity of fatigue. It is validated for LC patients
From baseline (day 0) to end of follow up at day 30
Cognitive failure questinonaire
Time Frame: From baseline (day 0) to end of follow up (day 30)
Assess cognitive impairment (25 questions, 0-100 score).Higher scores indicat increased propensity to cognitive impairment and it is validated for LC
From baseline (day 0) to end of follow up (day 30)

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Université de Sherbrooke

Collaborators

Collaborators

An organization other than the sponsor that provides support for a clinical study. This support may include activities related to funding, design, implementation, data analysis, or reporting.
Centre de recherche du CHU de Sherbrooke

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

Helpful Links

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
May 1, 2025

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
November 1, 2025

Study Completion (Actual)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
December 1, 2025

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
February 10, 2026

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
February 10, 2026

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
February 18, 2026

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
February 18, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
February 10, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
February 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • PF study
  • Programme PAFI 2024-2025 (Other Identifier: Centre de recherche du CIUSSSE-CHUS)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

IPD Plan Description

Except for the study protocol that we are willing to share, personal and confidential will not be shared

Study Data/Documents

  1. Study Protocol
    Information comments: christine.rioux-perreault.ciussse-chus@ssss.gouv.qc.ca

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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