Health Guide

Isoquercetin

Meet Isoquercetin: a potent, bioavailable form of Quercetin, one of nature's most powerful antioxidants found in everyday foods like onions and apples. While regular Quercetin struggles to be absorbed by the body, Isoquercetin is the 'bio-active' version your cells can use immediately. Think of it as nature's cellular bodyguard, helping to manage inflammation, stabilize your energy levels, and protect your DNA from daily stress.
Evidence BasedDietary Supplement
Isoquercetin
VERIFIED SOURCE

Bio-Activity Analysis

Bioavailability: Quercetin vs. Isoquercetin

SCIENTIFIC DATA VISUALIZATION

Y-Axis
Absorption Rate (Cmax)
Compound Type

Health Benefits & Sources

Why You Need It

  • Superior Absorption: Unlike standard Quercetin, Isoquercetin is water-soluble, meaning it enters your bloodstream faster and more efficiently.
  • Natural Antihistamine: It helps stabilize mast cells (the cells that release histamine), providing natural relief for seasonal sensitivities.
  • Cellular Longevity: It activates 'longevity genes' (sirtuins) that help repair DNA and slow cellular aging.

Deep Dive

Isoquercetin belongs to a group of plant compounds called flavonoids. Its primary superpower is its bioavailability. Most Quercetin supplements pass through you without being fully absorbed. Isoquercetin, however, is often found in the small intestine and enters the bloodstream directly. This makes it highly effective for managing acute inflammation and oxidative stress. It works by 'quenching' free radicals—unstable molecules that damage cells—and by inhibiting the release of inflammatory messengers in the body.

Natural Food Sources

Isoquercetin is found in varying amounts in the skins of many fruits and vegetables. However, cooking and processing can reduce these levels.

FoodAmount% DV (Estimate)
Capers100g2300%
Dill Weed100g1900%
Lovage100g1500%
Onions (Red/Yellow)1 Medium15%
Apple (with skin)1 Medium10%

Supplementation

Because Isoquercetin is a specific chemical isomer, it is almost exclusively taken as a supplement to achieve therapeutic doses.

  • Typical Dosage: 10mg to 50mg per day. This is significantly lower than standard Quercetin (500mg) because it is so potent.
  • Who Should Take It: Individuals with seasonal sensitivities, those looking for anti-aging support, or people who do not eat enough onions, capers, or apples.

Top Food Sources

Capers
Highest natural density
Red Onions
Eat raw for max benefit
Apples
Concentrated in the skin
Dill
Fresh herb form
Green Beans
Good for volume

Frequently Asked Questions

No. Regular Quercetin is poorly absorbed. Isoquercetin is a specific form (a glucoside) that your body absorbs much faster, making it more effective at lower doses.
Bromelain is often added to Quercetin to boost absorption, but because Isoquercetin is already highly bioavailable, it is less necessary, though still safe to combine.
To get the therapeutic dose used in studies (10mg+), you would need to eat a large amount of raw onions daily. Supplementation ensures consistency.
Isoquercetin supplements are usually derived from natural sources (like Sophora Japonica flowers) but processed to isolate the specific molecule. It is chemically identical to the Isoquercetin found in nature.

Safety & Side Effects

Isoquercetin is generally recognized as safe (GRAS) at dietary and supplemental levels.

Side Effects: Mild digestive upset or headache if taken on an empty stomach.

Chemical Safety: While chemically distinct from 'Quercetin Dihydrate,' they share similar safety profiles.

Interactions:

  • Blood Thinners: It may have a mild blood-thinning effect; use caution if taking Warfarin.
  • Pregnancy: There is insufficient data on high-dose supplementation during pregnancy; stick to dietary sources.

Scientific References

  • [1]Mlcoch, T., et al. (2021). 'Isoquercetin and its derivatives: A review on pharmacological activities.' *Biomedicine & Pharmacotherapy*.
  • [2]Valenzuela, A., et al. (2018). 'Enhanced bioavailability of quercetin in humans.' *Journal of Functional Foods*.
  • [3]National Institutes of Health (NIH) - Office of Dietary Supplements: Flavonoid Fact Sheet.