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Study on Metformin and Colchicine for Patients with Long COVID Symptoms

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What is this trial about?

A plain-language summary of the goals, design and what participants do

This clinical trial is focused on studying treatments for Post-Acute Sequelae of SARS-CoV-2 Infection (PASC), which refers to the long-term effects some people experience after recovering from COVID-19. The study will evaluate the effectiveness of two medications: Metformin and colchicine. Metformin is commonly used to manage blood sugar levels in people with diabetes, while colchicine is often used to reduce inflammation and treat conditions like gout.

The purpose of the study is to understand how these treatments impact the physical health-related quality of life for individuals experiencing PASC. Participants will be randomly assigned to receive either metformin, colchicine, or a placebo. The study will last for a period of 12 weeks, during which participants will take the assigned treatment orally in tablet form. The maximum daily dose for metformin is 1500 mg, and for colchicine, it is 1 mg. The study will monitor the participants' health and any changes in their symptoms throughout this period.

At the end of the 12 weeks, the study will assess the participants' physical health using a standardized questionnaire. This will help determine if the treatments have improved their quality of life. The study will also look at other aspects of health, such as mental well-being and the ability to perform daily activities. The findings from this trial could provide valuable insights into managing the long-term effects of COVID-19.

The research process

The trial runs in 6 steps – from screening to follow-up. Each step says what happens and what the team monitors.

  1. Step 1

    Initial assessment

    Upon joining the study, an initial assessment is conducted to confirm eligibility. This includes verifying age, residence, and the presence of persistent symptoms related to post-acute sequelae of SARS-CoV-2 infection (PASC) for at least 12 weeks after infection.

    Confirmation of a previous SARS-CoV-2 infection is required through a positive test or a diagnosis by a medical specialist.

  2. Step 2

    Informed consent

    Participants must provide informed consent, indicating their willingness to participate and comply with trial procedures.

    Consent includes allowing the exchange of relevant medical information between the participant's general practitioner or pharmacy and the trial team.

  3. Step 3

    Medication administration

    Participants receive either metformin or colchicine as part of the trial. Both medications are administered orally.

    The specific dosage and frequency of administration are determined by the trial protocol and communicated to participants at the start of this phase.

  4. Step 4

    Monitoring and assessments

    Throughout the trial, participants undergo regular monitoring to assess their health-related quality of life (HRQoL) and other health parameters.

    Primary assessments occur at 12 weeks, focusing on physical health using the Patient-Reported Outcomes Measurement Information System Profile29 (PROMIS-29).

  5. Step 5

    Secondary assessments

    Secondary assessments at 12 weeks include mental health, fatigue, pain interference, and other domains using PROMIS-29 and additional questionnaires.

    Adherence to the medication regimen is evaluated, and any adverse events are recorded and analyzed.

  6. Step 6

    Follow-up

    A follow-up assessment is conducted 12 weeks after the cessation of medication use, totaling 24 weeks from the start of the trial.

    This assessment evaluates the maintenance of treatment success in terms of HRQoL.

Who can join the trial?

9 criteria

  • Adults aged 18 years or older.
  • Living in the study area for the entire time they are part of the trial.
  • Having ongoing signs and symptoms of PASC (post-acute sequelae of SARS-CoV-2 infection), such as feeling very tired (fatigue) or feeling worse after physical or mental activity (PEM), for at least 12 weeks after getting a SARS-CoV-2 infection. These symptoms should not have been present before the infection, but they might have gotten better and then come back after the infection.
  • Being able to confirm they had a SARS-CoV-2 infection by one of the following:
    • A positive result from a nucleic acid amplification test (NAAT), like a PCR test.
    • A positive result from a rapid diagnostic test for SARS-CoV-2, including tests done at home.
    • A COVID-19 diagnosis made by a doctor, based on the tests mentioned above or other medical tests and evaluations.
    • Willing and able to give their agreement (informed consent) to participate in the trial.
    • Willing and able to follow the trial procedures.
    • Allowing their doctor or pharmacy and the trial team to share medical information that is important for their safety and the trial assessments.

Who cannot join the trial?

4 criteria

  • Individuals who have not experienced PASC, which stands for post-acute sequelae of SARS-CoV-2 infection. This refers to ongoing health issues that occur after recovering from the initial COVID-19 infection.
  • Individuals who are not within the specified age range for the study.
  • Individuals who do not meet the gender requirements for the study.
  • Individuals who are part of a vulnerable population that the study is not designed to include.
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Investigated drugs

  • Metformin

    is a medicine that has been used for decades to treat type 2 diabetes. It is taken by mouth as tablets, lowers blood sugar and improves metabolism, and also appears to dampen inflammatory processes in the body. In this trial it is being tested to find out whether it can reduce long-lasting symptoms after a COVID-19 infection, known as long COVID, and so improve physical quality of life.

  • Colchicine

    is an anti-inflammatory medicine traditionally used for gout and certain inflammations of the sac around the heart. It is taken by mouth as tablets and curbs the activity of inflammatory cells, which may ease persistent inflammatory reactions in the body. In this trial it is being evaluated as a treatment for ongoing symptoms after COVID-19.

  • Minocycline

    is an antibiotic from the tetracycline group that has been in use for many years. Beyond fighting bacteria, it also has anti-inflammatory properties. In this trial it is taken by mouth as tablets to see whether it can relieve long-lasting symptoms after a COVID-19 infection.

  • Placebo

    is an inactive preparation that looks identical to the active study tablets but contains no active substance. It allows researchers to compare results and measure the true effects of the study medicines.

What is already known about the treatment

  • Metformin

    Metformin is a medicine taken by mouth in tablet form, used for decades as a first-choice treatment for type 2 diabetes. It belongs to the biguanide class and works mainly by reducing sugar production in the liver and increasing the sensitivity of cells to insulin, effects linked to the activation of an enzyme called AMP kinase, which regulates the energy metabolism of cells. It is a safe, affordable and very well studied medicine, and recent research also suggests possible anti-inflammatory and antiviral effects. In this study, metformin is being tested to see whether it can relieve the persistent symptoms that follow SARS-CoV-2 infection, known as post-COVID syndrome.

  • Colchicine

    Colchicine is an anti-inflammatory medicine taken by mouth, originally obtained from a plant called the autumn crocus and used for a very long time in the treatment of gout and pericarditis (inflammation of the lining around the heart). It works by blocking microtubules, small structures inside cells, which prevents the movement and activation of inflammatory cells and thus reduces inflammation in the body. Because of its general anti-inflammatory effect, it is being studied more and more intensively in cardiovascular diseases and viral infections. In this study, colchicine is being evaluated as a possible treatment for the long-lasting symptoms that appear after SARS-CoV-2 infection.

  • Minocycline

    Minocycline is an antibiotic from the tetracycline class, taken by mouth as tablets or capsules. It works by blocking bacterial ribosomes, the structures that produce proteins, thereby stopping bacteria from multiplying; in addition, it has anti-inflammatory and nerve-cell-protective effects that are independent of its antibacterial action. It has long been used to treat acne and certain respiratory or urinary tract infections, and its anti-inflammatory properties are being investigated in neurological diseases. In this study, minocycline is being tested for the relief of persistent symptoms following SARS-CoV-2 infection.

Investigated diseases

Post-Acute Sequelae of SARS-CoV-2 Infection (PASC) – This condition refers to a range of symptoms that persist after the acute phase of a COVID-19 infection has resolved. Individuals may experience ongoing fatigue, difficulty breathing, joint pain, and cognitive issues, often described as "brain fog." Symptoms can vary widely among individuals and may affect multiple organ systems. The condition can develop weeks or even months after the initial infection, regardless of the severity of the acute illness. It is sometimes referred to as "long COVID" and can significantly impact daily functioning and quality of life. The exact cause of these prolonged symptoms is still under investigation.
Trial detailsLast updated 30 Oct 2026
Age18+ yearsPhasePhase IIITrial ID2024-511580-28-02Estimated enrolment2 000 patientsSponsorUniversitair Medisch Centrum Utrecht

sourced from the EU Clinical Trials Register and site verification

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