Pycnogenol® in Post-COVID-19 Condition

To determine the effect of Pycnogenol® versus placebo on patient-reported health status in people with post COVID-19 condition.

The primary aim of this 12-week quadruple blind, single-center randomized controlled trial is to determine the effect of Pycnogenol® (200mg daily) versus placebo on patient-reported health status (EQ-Visual Analogue Scale) in people with post COVID-19 condition. Secondary outcomes include symptoms, fatigue, cognitive function, health-related quality of life, functional exercise capacity and blood biomarkers of inflammation, endothelial function and oxidative stress.

Pycnogenol® is a licensed pine tree bark extract (Pinus pinaster ssp. atlantica) and primarly used for the treatment of venous disorders. Various studies reported beneficial effects in other conditions such as diabetes, metabolic syndrome and cardiovascular disorders. Pycnogenol® exerts antioxidative, anti-inflammatory and antiproliferative effects and has been shown to improve vascular endothelial function. Pycnogenol® may have potential to improve the health status of people suffering from post COVID-19 condition.

This trial lasts for 12 weeks. Participants are invited to visit the study center four times: screening visit, baseline visit, follow-up 1 visit (6 weeks after baseline visit), follow-up 2 visit (12 weeks after baseline visit).

In a substudy using baseline data, the investigators plan to study associations between objectively measured physical activity, severity of post COVID-19 condition, symptom burden and severity (e.g., fatigue, dyspnoea), functional exercise capacity, and health-related quality of life.

Eligibility Criteria:
Inclusion Criteria:

* SARS-CoV-2 infection confirmed by positive PCR or rapid antigen test for professional use or written medical report
* Post-COVID condition (WHO definition), i.e., ≥ 3 months after SARS-CoV2 infection and ongoing or recurring symptoms for at least 2 months that cannot be explained by alternative diagnosis
* Symptoms include fatigue and / or cognitive impairment ("brain fog") and / or dyspnea and / or post-exertional malaise
* Willing to participate and having signed informed consent
* Sufficient language and cognitive skills
* Ability to participate in study visits
* No foreseeable change in medication

Exclusion Criteria:

* Severe comorbidities such as liver or renal failure, advanced COPD or pulmonary fibrosis requiring \> 5L oxygen/min at rest, active malignancy, advanced heart failure, cardio-vascular events within the previous 24 weeks (such as unstable coronary artery disease, coronary revascularization, myocardial infarction, stroke, transient ischemic attack, critical limb ischemia, pulmonary embolism, deep vein thrombosis), uncontrolled severe hypertension, uncontrolled diabetes uncontrolled autoimmune or inflammatory disease (the responsible study physician will decide each case on an individual basis)
* Acute respiratory or other infections (postpone baseline visit until resolved)
* Clinical diagnosis of a psychiatric disease (e.g., depression, anxiety disorder, schizophrenia) that is untreated and/or unstable (the responsible study physician will decide each case on an individual basis)
* COVID-19 vaccination less than 4 weeks prior to the baseline visit (i.e., first or second dose of a two-dose vaccination regimen, first dose of a single dose vaccination regimen, booster) or during study participation (booster shot will be offered at screening visit, wait time until baseline visit 4 weeks)
* Known intolerance of the study drug
* Regular intake of Pycnogenol®
* Pregnancy or lactating. For women and transgender individuals of childbearing age, who can anamnestically not exclude a pregnancy, are offered a pregnancy test during the study visits.
* Being enrolled in another interventional study that may interfere with the current study (the responsible study physician will decide each case on an individual basis)