Myricetin is a naturally occurring flavonoid — part of the same family as quercetin and kaempferol — found in a wide range of plants including berries, walnuts, onions, and red wine. It has been consumed as part of traditional diets across Europe, Asia, and the Americas for centuries without being singled out as a supplement until modern research identified its potent biological activity. As an isolated supplement, it is now studied for its unusually broad range of protective effects on metabolism, the heart, and the brain.

Myricetin works primarily as a scavenger of harmful free radicals, protecting cells from oxidative damage that drives aging and chronic disease. It also helps dial down inflammation by blocking several key inflammatory signaling pathways in the body. Uniquely among flavonoids, myricetin has been shown to mimic some actions of insulin by activating glucose transport into cells, which helps explain its blood-sugar-lowering effects.

As a supplement, myricetin is available in capsule or powder form, sometimes standardized from plant sources like bayberry bark (Myrica rubra) or Chinese wax myrtle. It also appears in broad-spectrum polyphenol and flavonoid blends. Standardized extracts typically deliver 50–500 mg per serving. Pure powder can be mixed into beverages but has a slightly astringent, bitter taste.

• Blood sugar and insulin resistance
• Heart health and cholesterol
• Inflammation and oxidative stress
• Brain protection and cognitive decline
• High blood pressure
• Cancer risk reduction
• Metabolic syndrome
• Obesity and weight management
• Liver health
• Anxiety and mood

• Prostate cancer (epidemiological evidence links higher dietary myricetin intake to reduced risk)
• Oxidative damage to LDL cholesterol (direct mechanistic and observational support)
• Cognitive decline associated with aging (supported by flavonoid-rich diet cohort studies)

• Bayberry / Wax myrtle (Myrica rubra) — One of the richest botanical sources of myricitrin, the glycoside form of myricetin; used in traditional medicine specifically for this compound.
• Black elderberries — Among the highest myricetin concentrations found in commonly eaten fruits, also rich in complementary flavonoids.
• Cranberries — Significant source of myricetin alongside quercetin and other flavonols; both fresh and dried forms contain meaningful amounts.
• Walnuts — One of the better nut sources of myricetin, concentrated especially in the papery skin between walnut segments.
• Red wine (and red grape skins) — Contains myricetin as part of a broad polyphenol profile; grape skins and seeds are the concentrated source, making dark grape juice a non-alcoholic alternative.

• Mild digestive upset or nausea at high doses (500 mg+)
• Reduced iron absorption when taken with meals containing non-heme iron
• Theoretical mild thyroid suppression at very high supplemental doses — not well documented in humans at normal use levels
• May lower blood sugar more than expected when combined with diabetes medications
• Rare: headache or mild fatigue during initial use

• Recommended daily: 100–500 mg of standardized myricetin extract daily; most studied doses in human research fall in the 150–300 mg range
• Best time of day: With meals — ideally once in the morning and once in the evening if splitting the dose, to maintain steady levels throughout the day
• With or without food: Best taken with food to improve absorption and minimize any digestive discomfort; avoid pairing with high-iron meals if also taking iron supplements
• Time to effect: Antioxidant activity begins acutely; blood sugar and anti-inflammatory benefits become measurable after 4–8 weeks of consistent daily use
• How long to take it: Can be taken continuously as part of a daily supplement routine; no established need for cycling. Periodic review with a healthcare provider is sensible for anyone on medications, especially blood sugar or blood-thinning drugs.