# Indena Quercefit (Quercetin Phytosome)

**Canonical URL:** https://ingredients.hermeticasuperfoods.com/ingredients/indena-quercefit
**Data Source:** Hermetica Superfoods Ingredient Encyclopedia
**Updated:** 2026-04-01
**Evidence Score:** 2 / 10
**Category:** Other
**Also Known As:** Quercetin Phytosome, Sophora japonica quercetin, Japanese pagoda tree quercetin, Phytosomated quercetin, Lecithin-complexed quercetin, Bioavailable quercetin complex

## Overview

Quercefit is a patented phytosome formulation of quercetin developed by Indena, in which quercetin is complexed with sunflower-derived phospholipids to dramatically enhance oral absorption. It works primarily by modulating NF-kB signaling and inhibiting COX and LOX enzymes, reducing pro-[inflammatory](/ingredients/condition/inflammation) mediator synthesis in joint and immune tissues.

## Health Benefits

• Enhanced bioavailability: 20-fold higher plasma exposure compared to unformulated quercetin (pharmacokinetic study, n=14 healthy volunteers, PMID: 30813433)
• [Inflammatory pathway](/ingredients/condition/inflammation) modulation: May inhibit NF-kB and control COX/LOX enzymes (mechanism-based evidence only)
• [Immunomodulat](/ingredients/condition/immune-support)ion support: Potential histamine/IgE reduction and IFN-γ promotion (preclinical data)
• Cellular health: May influence [autophagy](/ingredients/condition/longevity), mitophagy, and senescent cell management (mechanism-based evidence)
• Respiratory health support: Claimed benefits rely on general quercetin data, not Quercefit-specific clinical trials

## Mechanism of Action

Quercefit delivers quercetin complexed with phosphatidylcholine, allowing passive diffusion across intestinal epithelial membranes and bypassing the poor solubility that limits standard quercetin absorption. Once absorbed, quercetin inhibits IκB kinase (IKK), preventing NF-kB nuclear translocation and downstream transcription of [pro-inflammatory cytokine](/ingredients/condition/inflammation)s such as TNF-α and IL-6. Quercetin also competitively inhibits cyclooxygenase (COX-1/COX-2) and 5-lipoxygenase (5-LOX), reducing prostaglandin E2 and leukotriene B4 synthesis in synovial and immune cells.

## Clinical Summary

A pharmacokinetic crossover study in 14 healthy volunteers (PMID: 30813433) demonstrated that Quercefit achieves approximately 20-fold greater plasma exposure (AUC) compared to unformulated quercetin at an equivalent dose, establishing its superior bioavailability. This enhanced absorption is the foundational clinical evidence for the formulation's advantage over standard quercetin supplements. Evidence for downstream [anti-inflammatory](/ingredients/condition/inflammation) and joint health outcomes is currently based on mechanistic and preclinical data, with limited controlled human trials specifically using Quercefit in joint disease populations. More robust randomized controlled trials with clinical endpoints such as joint pain scores, CRP, and IL-6 are needed to confirm therapeutic efficacy in target populations.

## Nutritional Profile

{"bioactive_compounds": {"quercetin": {"concentration": "500 mg per serving", "bioavailability": "Enhanced, 20-fold higher plasma exposure compared to unformulated quercetin"}}, "macronutrients": {"protein": "Not applicable", "fiber": "Not applicable"}, "micronutrients": {"vitamins": "Not applicable", "minerals": "Not applicable"}}

## Dosage & Preparation

Clinically studied doses: 250 mg Quercefit tablets (delivering ~100 mg quercetin) up to 500 mg (delivering ~200 mg quercetin), showing linear absorption. Standardization: ~40% total quercetin (HPLC) in phytosome powder form. Consult a healthcare provider before starting any new supplement.

## Safety & Drug Interactions

Quercefit and quercetin broadly are well-tolerated in studies up to 1,000 mg/day, with mild gastrointestinal discomfort being the most commonly reported side effect. Quercetin may inhibit CYP3A4 and CYP2C8 enzymes, potentially increasing plasma concentrations of drugs such as cyclosporine, statins, and certain anticoagulants like warfarin, warranting caution in patients on these medications. Quercetin has demonstrated estrogen-receptor binding activity in preclinical models, so individuals with hormone-sensitive conditions should consult a physician before use. Safety data in pregnant or breastfeeding women is insufficient to establish a recommendation, and use during pregnancy should be avoided without medical supervision.

## Scientific Research

The primary clinical evidence comes from an open-label, crossover pharmacokinetic study (PMID: 30813433) comparing Quercetin Phytosome to unformulated quercetin in 14 healthy volunteers, demonstrating 20-fold higher plasma exposure and dose linearity up to 500 mg. No large-scale RCTs, meta-analyses, or efficacy trials specifically on Quercefit for clinical outcomes are available; therapeutic claims rely on preclinical or general quercetin data.

## Historical & Cultural Context

Quercetin occurs naturally in vegetables, fruits, nuts, and oaks (named from Latin 'quercetum' for oak forest). No specific historical or traditional medicine uses for Quercefit or Sophora japonica-derived quercetin are documented in the available research.

## Synergistic Combinations

Vitamin C, Bromelain, Resveratrol, Curcumin, Green Tea Extract

## Frequently Asked Questions

### How much more absorbable is Quercefit compared to regular quercetin?

A pharmacokinetic crossover study (PMID: 30813433, n=14 healthy volunteers) found Quercefit produces approximately 20-fold greater plasma AUC than an equivalent dose of unformulated quercetin. This improvement is achieved by complexing quercetin with phosphatidylcholine derived from sunflower lecithin, which facilitates transport across lipid-rich intestinal membranes and reduces first-pass degradation.

### What is the recommended dosage of Quercefit for joint health?

Indena's Quercefit is typically studied and commercially formulated at doses of 250–500 mg per day, often split into two doses, reflecting the dose range used in pharmacokinetic evaluations. Because of its 20-fold bioavailability advantage, effective quercetin exposure from 250 mg Quercefit may approximate that of much larger doses of standard quercetin powder. Individual dosing should be confirmed with a healthcare provider, particularly for those on medications metabolized by CYP3A4.

### Does Quercefit reduce joint inflammation?

Quercefit delivers quercetin, which inhibits NF-kB activation, COX-1/COX-2, and 5-lipoxygenase, all of which are central mediators of joint inflammation responsible for prostaglandin E2 and leukotriene B4 production. While this mechanistic rationale is well-supported in cell and animal models, direct randomized controlled trials using Quercefit specifically in osteoarthritis or rheumatoid arthritis patients are limited, meaning clinical evidence remains preliminary and more trials are needed.

### Can Quercefit interact with blood thinners or other medications?

Yes, quercetin inhibits CYP3A4 and CYP2C8 hepatic enzymes, which can slow the metabolism of warfarin, cyclosporine, and certain statins, potentially elevating their plasma levels and increasing the risk of side effects. Additionally, quercetin's antioxidant activity may have additive effects with antiplatelet drugs. Anyone taking anticoagulants, immunosuppressants, or cholesterol-lowering medications should consult their physician before adding Quercefit to their regimen.

### What makes Quercefit different from other quercetin supplements on the market?

Quercefit is a patented phytosome technology from Indena SpA, a pharmaceutical-grade botanical ingredient manufacturer, in which quercetin molecules are individually bound to phosphatidylcholine at a defined molecular ratio, forming a lipid-compatible complex. This distinguishes it from simple quercetin powder, quercetin dihydrate, or even quercetin combined with bromelain, none of which have demonstrated equivalent pharmacokinetic improvements in head-to-head human studies. The PMID: 30813433 study provides third-party clinical evidence for its bioavailability advantage, which is a level of documentation uncommon among quercetin products.

### Is Quercefit safe for children and pregnant women?

Clinical safety data for Quercefit is primarily established in adult populations, and there is insufficient evidence to recommend its use during pregnancy or breastfeeding. Parents considering Quercefit for children should consult a healthcare provider, as pediatric dosing and safety have not been formally studied. Pregnant and nursing women should avoid Quercefit unless explicitly cleared by their physician.

### How does the phytosome technology in Quercefit improve absorption compared to quercetin alone?

Quercetin is naturally poorly absorbed due to its large molecular structure and low lipophilicity; the phytosome complex in Quercefit binds quercetin to phospholipids, which improves cellular uptake and intestinal permeability. This proprietary formulation delivers 20-fold higher plasma exposure than unformulated quercetin in clinical studies, meaning more of the active ingredient reaches your bloodstream. The enhanced bioavailability allows for lower doses to achieve therapeutic effects.

### What does the research evidence show about Quercefit's effectiveness for immune function?

Preclinical research suggests Quercefit may support immune function by modulating histamine and IgE responses and promoting interferon-gamma (IFN-γ) production, which supports cellular immunity. However, most of this evidence is from laboratory and animal studies rather than human clinical trials, so definitive claims about immune benefits in humans require further research. Current human data primarily focuses on bioavailability and inflammatory markers rather than comprehensive immune outcomes.

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*Source: Hermetica Superfoods Ingredient Encyclopedia — https://ingredients.hermeticasuperfoods.com*
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