Supplement · Antioxidants, immune & general wellness
Quercetin
An anti-inflammatory flavonoid with modest evidence for blood pressure and, tentatively, endurance.
- Evidence
- Silver· human data
- Sources cited
- 1
- Last reviewed
- 22 July 2026
Quercetin is a plant flavonoid (in onions, apples and capers) with antioxidant and anti-inflammatory actions, studied for blood pressure, immunity, allergies and exercise.
The more consistent human signal is a modest reduction in blood pressure; endurance and immune effects are small and inconsistent, partly because quercetin is poorly absorbed. It also features in 'senolytic' research (often paired with fisetin or dasatinib), but that work is early. A low-risk flavonoid with modest, specific evidence.