Quercefit® (Quercetin Phytosome — Indena)

Sophora japonica
Evidence Level
Strong
2 Clinical Trials
6 Documented Benefits
4/5 Evidence Score

Quercefit® is a QUERCETIN PHYTOSOME® formulation developed by Indena (Italy) — using Phytosome® technology to address quercetin's notoriously poor bioavailability (typically <2% from food sources). Quercetin is a flavonoid found in many plants. Recently studied for respiratory health, allergic rhinitis, and exercise performance. Distinguished by enhanced bioavailability and human clinical trials.

Studied Dose 250-500 mg/day Quercefit (research-validated)
Active Compound Quercetin Phytosome® (quercetin-phosphatidylcholine complex from Sophora japonica)

Benefits

Respiratory Wellbeing in Sensitive/Intolerant Subjects

Two human studies showed Quercefit benefits for sensitive or intolerant subjects in respiratory area. Allergic respiratory and seasonal airway applications.

Allergic Rhinitis Adjunct

Quercetin has documented anti-histamine and mast cell stabilizing effects; Quercefit's bioavailable form delivers these effects more reliably.

Exercise Performance and Recovery

Some trials show quercetin (including Quercefit form) improves exercise capacity, reduces oxidative stress from exercise, supports recovery.

20× Bioavailability vs Standard Quercetin

Phytosome technology dramatically improves quercetin absorption — addresses standard quercetin's <2% bioavailability.

Anti-Inflammatory and Antioxidant

Quercetin is potent flavonoid antioxidant with documented anti-inflammatory effects; relevant to multiple conditions involving oxidative stress and inflammation.

Mast Cell Stabilization

Quercetin stabilizes mast cells (histamine-releasing cells) — mechanism for allergic and inflammatory applications.

Mechanism of action

1

Mast Cell Stabilization

Quercetin inhibits mast cell degranulation — reduces histamine and inflammatory mediator release. Mechanism for allergy and inflammatory applications. Similar to cromolyn pharmaceutical mechanism.

2

Histamine H1 Receptor Antagonism (Modest)

Modest H1 receptor antagonism — adds to mast cell stabilization for anti-allergic effects.

3

NF-κB Inhibition

Inhibits NF-κB inflammatory pathway — anti-inflammatory mechanism.

4

Phytosome® Bioavailability Enhancement

Standard quercetin has very low bioavailability (<2%); Phytosome® improves absorption by ~20× — addresses major limitation of quercetin supplementation.

5

Antioxidant / Free Radical Scavenging

Direct antioxidant activity; activation of NRF2 pathway for endogenous antioxidant defenses.

Clinical trials

1
Quercefit for Respiratory Health — Riva 2019
PubMed

Studies of Quercefit on respiratory wellbeing in sensitive/intolerant subjects.

Adults with respiratory sensitivity.

Improvements in respiratory comfort during seasonal challenges. Established Quercefit respiratory applications.

2
Quercetin for Exercise Performance — General Evidence
PubMed

Multiple quercetin trials on exercise performance and recovery.

Athletes and active populations.

Modest improvements in exercise capacity, oxidative stress reduction, recovery markers.

About this ingredient

About the active ingredient

QUERCEFIT® is a QUERCETIN PHYTOSOME® formulation developed by INDENA (Italy) — using PHYTOSOME® technology applied to QUERCETIN. QUERCETIN BACKGROUND: a FLAVONOID widely found in plants — apples (especially skin), onions, capers, berries, kale, broccoli; one of most-studied flavonoid antioxidants. CHALLENGE: standard quercetin has VERY POOR ORAL BIOAVAILABILITY (<2%) — most ingested quercetin is not absorbed. Quercefit addresses this.

KEY DISTINCTIONS: (1) PHYTOSOME® TECHNOLOGY for enhanced bioavailability (~20× improvement); (2) Sourced from SOPHORA JAPONICA flowers; (3) HUMAN CLINICAL TRIALS for respiratory health and exercise; (4) Pharmaceutical-grade Indena quality.

EVIDENCE-BASED USES: (1) RESPIRATORY WELLBEING (sensitive/intolerant subjects); (2) Allergic rhinitis adjunct; (3) Exercise performance and recovery; (4) Anti-inflammatory; (5) Antioxidant support; (6) Mast cell stabilization.

CRITICAL CAUTIONS: (1) DOSE — 250-500 mg/day; (2) PREGNANCY — quercetin in food safe; concentrated supplementation limited safety data; AVOID high-dose; (3) CYCLOSPORINE — quercetin inhibits CYP3A4 increasing cyclosporine levels; relevant for transplant patients; consult; (4) ANTICOAGULANTS — modest interactions; (5) PRE-SURGERY — discontinue 1-2 weeks; (6) ALLERGIC RHINITIS APPLICATIONS — quercetin's mast cell stabilization mechanism is relevant; quercetin not replacement for antihistamines or nasal corticosteroids in moderate-severe rhinitis but reasonable adjunct; (7) DURATION — anti-allergic effects build over weeks; preventive use before allergy season ideal; (8) QUERCEFIT vs STANDARD QUERCETIN — the 20× bioavailability advantage is clinically meaningful; standard quercetin supplements often underperform; (9) FOR EXERCISE — modest performance effects; oxidative stress reduction more reliably documented; (10) DRUG-DRUG INTERACTIONS — quercetin's CYP3A4 inhibition relevant for many medications; consult prescriber; (11) BRAND VERIFICATION — Quercefit® and Phytosome® are Indena trademarks; clinical evidence specific to this technology; (12) For COMPREHENSIVE ALLERGY MANAGEMENT — antihistamines, nasal corticosteroids, environmental control, supplementation (Quercefit, vitamin C); integrative approach.

Side effects and drug interactions

Common Potential side effects

Generally well-tolerated.
Mild GI distress.
Headache rare.
Allergic reactions rare.
Theoretical anticoagulant effects at very high doses.

Important Drug interactions

ANTICOAGULANTS — modest interactions.
Cyclosporine — quercetin may increase cyclosporine levels via CYP3A4 inhibition; consult.
Some chemotherapy drugs — theoretical interactions.
Diabetes medications — modest hypoglycemic effects.
Pregnancy — quercetin in food (apples, onions) safe; concentrated supplementation limited safety data; AVOID high-dose supplementation.
Lactation — limited data.
SOY ALLERGY — Phytosome phosphatidylcholine consideration.

Frequently asked questions about Quercefit® (Quercetin Phytosome — Indena)

What is the recommended dosage of Quercefit® (Quercetin Phytosome — Indena)?

The clinically studied dose for Quercefit® (Quercetin Phytosome — Indena) is 250-500 mg/day Quercefit (research-validated). Always follow product labeling and consult a healthcare provider for personalized dosing recommendations.

What is Quercefit® (Quercetin Phytosome — Indena) used for?

Quercefit® (Quercetin Phytosome — Indena) is studied for respiratory wellbeing in sensitive/intolerant subjects, allergic rhinitis adjunct, exercise performance and recovery. Two human studies showed Quercefit benefits for sensitive or intolerant subjects in respiratory area. Allergic respiratory and seasonal airway applications.

Are there side effects from taking Quercefit® (Quercetin Phytosome — Indena)?

Reported potential side effects may include: Generally well-tolerated. Mild GI distress. Always consult a healthcare provider before starting any new supplement, especially if you have underlying conditions or take medications.

Does Quercefit® (Quercetin Phytosome — Indena) interact with medications?

Known drug interactions may include: ANTICOAGULANTS — modest interactions. Cyclosporine — quercetin may increase cyclosporine levels via CYP3A4 inhibition; consult. Consult a pharmacist or healthcare provider if you take prescription medications.

Is Quercefit® (Quercetin Phytosome — Indena) good for respiratory health?

Yes, Quercefit® (Quercetin Phytosome — Indena) is researched for Respiratory Health support. Two human studies showed Quercefit benefits for sensitive or intolerant subjects in respiratory area. Allergic respiratory and seasonal airway applications.