Fisetin for Antioxidant Protection
Fisetin has strong antioxidant activity in laboratory models but essentially no human data.
Overview
Verdict
How It Works
Dosing & Protocol
Typical dose
- Recommended dose
- Not established; human studies used 20 mg/kg/day for 2 days monthly (about 1400 mg/day) without measured antioxidant outcomes
- Expected timeframe
- Not established
Protocol
- form
- Not applicable
- duration
- Not applicable
- co factor
- Evidence is insufficient. Fisetin is a flavonoid found in strawberries, apples and persimmons with clear antioxidant and free-radical-scavenging activity in test tubes, and it raises glutathione in cell models. None of that has been shown to translate into meaningful antioxidant protection in humans: the small clinical trials that exist used 20 mg/kg/day for two consecutive days monthly and measured inflammatory and senescence markers, not oxidative stress outcomes, and fisetin has poor oral bioavailability and rapid metabolism. Antioxidant capacity is also a poor surrogate for health - high-dose antioxidant supplements have repeatedly failed or harmed in large trials.
- titration
- Not applicable
- starting dose
- Not applicable as an established treatment
Evidence
What the studies say
No studies are yet linked to both Fisetin and Antioxidant Protection.
Safety
Caveats
Fisetin has no established safe long-term dose in humans, no upper intake level, and no data in pregnancy or breastfeeding - avoid it in both. The doses used in trials (around 1400 mg/day for a 70 kg adult) are far above anything obtainable from food and are given intermittently precisely because chronic safety is unknown. Fisetin inhibits cytochrome P450 enzymes and the drug transporter P-glycoprotein in laboratory studies, so interactions with a wide range of prescription medicines are plausible but uncharacterised - do not combine it with anticoagulants, chemotherapy or narrow-therapeutic-index drugs. It has mild antiplatelet activity in vitro; stop before surgery. Avoid in children. Dietary flavonoids from fruit and vegetables carry none of these uncertainties.
Less likely to help if
Medical Disclaimer
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Individual results may vary. The statements on this website have not been evaluated by the Food and Drug Administration. Products and information are not intended to diagnose, treat, cure, or prevent any disease.