Kaempferol

PhytochemicalBest with a meal

What is it

Kaempferol is a yellow flavonoid found in many edible plants including kale, broccoli, onions, tea, capers, and various herbs. It is also a natural component of many flowering plants and is investigated for antioxidant, anti-inflammatory, and possibly anticancer effects.

Evidence for 2 uses

AI-assisted evidence assessment — talk to your doctor before relying on any single supplement.

Cardiovascular / anti-inflammatory

Limited Evidence

Observational studies link dietary kaempferol intake with reduced cardiovascular events; intervention studies on isolated kaempferol are limited.

Cancer prevention

Mixed Evidence

Preclinical evidence is promising; human clinical evidence is limited.

How it works

Kaempferol exhibits diverse biological activities in preclinical studies including antioxidant activity, inhibition of NF-kB inflammatory signaling, modulation of estrogen receptors (weak phytoestrogen), inhibition of various enzymes including aromatase, and induction of apoptosis in cancer cell lines. Kaempferol bioavailability is limited in humans (typically <2% absorbed unchanged), with extensive phase II metabolism (glucuronidation, sulfation). Most circulating kaempferol after dietary intake is in conjugated forms with somewhat different activities than the aglycone.

Dosage

No established supplement RDA. Typical dietary intake: 2-30 mg/day. Supplement doses range from 10-500 mg.

When and how to take it

WHEN: With meals for better absorption. HOW: Whole-food sources or supplement per product instructions.

2 commercial forms

Compare the main delivery options and what they’re best suited for.

Kaempferol aglycone (supplement)

Available as isolated supplement.

Limited oral bioavailability

Kaempferol glucosides (dietary)

Natural form in foods.

Some glycosides absorbed differently

Safety

Dietary kaempferol from foods is considered safe. Concentrated supplement doses have less established safety data; some studies suggest possible effects on thyroid and hormone-sensitive tissues at high doses.

Who should be cautious

Avoid high-dose supplements in pregnancy and lactation. Caution in hormone-sensitive conditions and with anticoagulants.

Interactions

Inhibits various CYP enzymes including CYP3A4, CYP2C9; theoretical interactions with many medications. May affect drugs metabolized by sulfation. Caution with anticoagulants (mild antiplatelet activity).

Food sources

Kale

Amount
1 cup = ~25 mg
%DV
—

Capers

Amount
1 tbsp = high amount
%DV
—

Onions

Amount
Variable
%DV
—

Frequently asked questions

How can I get more kaempferol?⌄

Eat plenty of dark leafy greens (kale, spinach), broccoli, onions, and tea. Dietary sources are the most studied.

Is kaempferol the same as quercetin?⌄

No, they are related flavonoids with overlapping activities but distinct molecular structures.

References

Kaempferol on Wikidata — Wikidata link

Kaempferol (ChEBI:28499) — ChEBI link

Kaempferol (PubChem CID 5280863) — PubChem link

Kaempferol on NIH DSLD (US supplement label database) — NIH Dietary Supplement Label Database link

Research on Kaempferol (PubMed search) — PubMed link

Track Kaempferol with Pilora

Set up dose reminders, check interactions, and join the community in the Pilora iPhone app.

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Evidence-based·How we grade evidence

Disclaimer: These statements have not been evaluated by the FDA. This page is educational, not a substitute for personalized medical advice. Evidence grades are AI-assisted assessments — talk to your doctor before starting any new supplement, especially if you’re pregnant, breastfeeding, on medications, or managing a chronic condition.