Quercetin is a flavonoid found in many fruits and vegetables and is known for its antioxidant and anti-inflammatory properties. There is emerging scientific interest in its potential neuroprotective effects, which is why it is sometimes used to support the brain and cognitive function. Preclinical studies (primarily in vitro and animal models) suggest that quercetin may protect neurons by scavenging free radicals, reducing neuroinflammation, and modulating signaling pathways involved in cell survival. For example, studies indicate that quercetin can attenuate oxidative stress in brain cells and may help limit neurodegeneration in models of Alzheimer’s and Parkinson’s diseases. Some research also suggests possible benefits in reducing cognitive decline associated with aging.

However, human clinical evidence is limited and inconsistent. A few small trials have examined quercetin supplementation in humans for cognitive performance or mood, but these studies are generally of low quality, with limited sample sizes and mixed results. As of now, there is insufficient robust clinical evidence to conclusively support quercetin’s use for brain health or neuroprotection in humans. Thus, while the rationale for its use is grounded in scientific exploration and early evidence, the overall strength of scientific validation is modest, and more rigorous clinical trials are needed.