DrFeb
Health Guide

isoquercitrin

Ever heard of **isoquercitrin**? It sounds like a complex chemical, but it's actually a brilliant little plant compound (a flavonoid) found naturally in everyday foods like onions, apples, and asparagus. Think of it as nature's 'bio-availability booster.' While similar to the antioxidant quercetin, isoquercitrin is structurally unique in a way that makes it **absorb much more efficiently** into your bloodstream. It acts as a powerful antioxidant and anti-inflammatory agent, helping your cells defend against daily stress and supporting your immune system.
Evidence BasedDietary Supplement
isoquercitrin
VERIFIED SOURCE

Bio-Activity Analysis

Bioavailability: Isoquercitrin vs. Quercetin Aglycone

SCIENTIFIC DATA VISUALIZATION

Y-Axis
Absorption Rate (AUC)
Compound Type →

Health Benefits & Sources

Why You Need It

  • Superior Absorption: Unlike its cousin quercetin (which is notoriously hard to absorb), isoquercitrin is taken up by the body much more easily.
  • Potent Antioxidant: It neutralizes harmful free radicals, protecting your cells from damage.
  • Anti-Inflammatory: Helps calm low-grade inflammation in the body.
  • Immune Support: May help regulate immune responses and histamine release.

Deep Dive

Isoquercitrin is a glycoside of quercetin. This means a sugar molecule is attached to it. This little sugar 'tail' is the secret to its effectiveness; it helps the compound pass through the intestinal wall. Once inside, your body cleaves off the sugar, releasing active quercetin where it's needed most. This makes isoquercitrin an ideal choice for those seeking the benefits of quercetin—such as allergy relief and cardiovascular protection—without the absorption issues.

Natural Food Sources

The best way to get isoquercitrin is through a diet rich in colorful fruits and vegetables. It is particularly concentrated in the skins of these foods.

FoodAmount% DV (Est.)
Capers10g (2 tsp)~10%
Buckwheat1 cup cooked~8%
Asparagus1 cup~5%
Apples (with skin)1 medium~4%
Red Onions1/2 cup raw~3%

Supplementation

Dosage: If supplementing with isoquercitrin (often labeled as 'Quercetin Glycosides'), typical dosages range from 100mg to 500mg daily.

Who Should Take It: This is ideal for individuals looking for natural allergy relief, athletes seeking to reduce exercise-induced inflammation, or older adults looking to support heart health. Since it absorbs well, you may see benefits at lower doses than standard quercetin supplements.

Top Food Sources

Capers
The highest known natural source
Buckwheat
Especially in the hulls
Asparagus
Concentrated in the tips
Red Apples
Eat the skin!
Red Onions
Higher in the outer layers

Frequently Asked Questions

No. Quercetin is the 'aglycone' (sugar-free) form. Isoquercitrin has a glucose molecule attached, which allows your body to absorb it significantly better.
For general health, yes. Eating onions, apples, and buckwheat regularly provides a good baseline. Supplements are useful for targeting specific issues like seasonal allergies.
It is relatively stable, but boiling can leach it into the water. Steaming or eating raw (like in salads) retains the highest amount.
That is its specific chemical name based on the position of the sugar molecule on the ring structure. It refers to the exact same compound.

Safety & Side Effects

Isoquercitrin is generally recognized as safe (GRAS) when consumed in food amounts. As a concentrated supplement:

  • Side Effects: Rare and mild. May include headache or stomach tingling if taken on an empty stomach.
  • Interactions: Because it can affect how the liver processes certain drugs, consult your doctor if you take blood thinners, chemotherapy drugs, or medications processed by the CYP3A4 enzyme.
  • Pregnancy: Safety in high supplemental doses is not fully established; stick to food sources if pregnant.

Scientific References

  • [1]Mlcek, J., et al. (2016). 'Quercetin and Its Anti-Allergic Immune Response.' *Molecules*.
  • [2]Hollman, P. C., & Katan, M. B. (1997). 'Absorption of dietary flavonols in humans.' *Free Radical Biology and Medicine*.
  • [3]Valentova, K., et al. (2014). 'Isoquercitrin: A dietary flavonoid with vastly superior bioavailability.' *Journal of Agricultural and Food Chemistry*.