EGb 761 for Post-COVID Cognitive Impairment

A Ginkgo Extract Trial Targets Post-COVID Brain Fog

For millions experiencing the lingering effects of COVID-19, cognitive impairment—often called “brain fog”—is a debilitating hallmark of Post-COVID-19 Syndrome (PCS). With no treatments yet approved to address its underlying pathology, management focuses on symptom relief. Now, a new clinical trial named EGb COCOS is putting a specific Ginkgo biloba extract, EGb 761®, to the test. Researchers Jordi A. Matias-Guiu, Katrin Arélin, and Paula Jiménez Serrano hypothesize that the extract’s properties could directly counter the suspected mechanisms driving PCS-related cognitive decline.

How the EGb COCOS Trial Is Designed

This is a prospective, multicentre, randomised, placebo-controlled, and triple-blind study. It plans to enroll 400 adults who have a history of SARS-CoV-2 infection, a PCS diagnosis with cognitive symptoms lasting at least two months, and objective cognitive impairment. Participants must also have mild-to-moderate anxiety or depressive symptoms.

Each participant will be randomly assigned to take either a 240 mg dose of EGb 761® or an identical-looking placebo once daily for 12 weeks. The triple-blind design means neither the participants, the clinicians administering the treatment, nor the researchers analyzing the data will know who is receiving the active extract.

The analysis will be exploratory, as there is no universally accepted primary endpoint for PCS cognitive studies yet. Researchers will assess changes across cognitive, neuropsychiatric, and neurosensory domains, which could include symptoms like tinnitus and hyperacusis. Safety will be monitored by recording all adverse events.

The Scientific Rationale Behind Using Ginkgo Biloba

The choice of EGb 761® is not arbitrary. The researchers point to three key pathological factors in PCS cognitive impairment: neuroinflammation, neurovascular dysfunction, and disrupted cellular energy metabolism in neurons. The standardized Ginkgo biloba extract has documented anti-neuroinflammatory effects, improves microcirculation (blood flow in small vessels), and supports mitochondrial function—the energy powerhouses of cells.

Previous clinical research has demonstrated EGb 761®’s efficacy in treating cognitive impairment from other causes, such as age-related decline. Small case series in PCS patients have also reported significant cognitive improvement after six months of treatment. This trial aims to provide the first high-quality evidence from a controlled study specifically for the PCS population.

Why This Trial Matters for Auditory and Sensory Health

While the primary focus is on cognition, the trial’s measurement of “neurosensory” outcomes is particularly relevant for an audience concerned with hearing health. Cognitive dysfunction in PCS often coexists with and may exacerbate conditions like tinnitus, misophonia, and hyperacusis. The brain’s auditory processing centers are susceptible to the same inflammatory and vascular challenges targeted by the Ginkgo extract.

Improvements in central cognitive processing could positively influence the perception and distress associated with these auditory conditions. This aligns with a broader understanding of auditory health as a brain-centered phenomenon. Furthermore, the trial’s exploration of neurovascular health connects to research on other sensory issues, such as the vascular links between sudden hearing loss and eye health.

Practical Implications and Future Directions

The results of the EGb COCOS trial, expected after its completion, will offer a clear answer on whether this specific Ginkgo biloba extract is a viable treatment option for PCS-related cognitive impairment. A positive outcome would provide clinicians with an evidence-based, mechanism-targeted intervention for a condition currently lacking specific treatments.

For patients, it represents hope for a treatment that goes beyond general coping strategies. The potential for concurrent improvement in cognitive and neurosensory symptoms could significantly enhance quality of life. It also underscores the importance of integrated approaches to post-viral syndromes, where cognitive and sensory health are deeply intertwined. Managing the cognitive load and distress from conditions like tinnitus may also benefit from strategies that improve overall brain resilience, similar to principles discussed in resources on sleep hygiene for cognitive function.

This trial, registered as CTIS2024-517199-39-00, is a direct response to an urgent clinical need. Its findings will determine whether a well-known botanical extract can be repurposed to address one of the most challenging chronic complications of the COVID-19 pandemic.

Source: Matias-Guiu JA, Arélin K, Serrano PJ. (2026). The EGb 761® Post COVID Cognitive Impairment Study (EGb COCOS): protocol for a clinical trial. Front Hum Neurosci. DOI: 10.3389/fnhum.2026.1658342.