Quercefit (Quercetin Phytosome): Bioavailable Quercetin for Anti-Inflammation, URI Prevention & Cardiovascular Health
⚡ 60-Second Summary
Quercefit is a patented ingredient (Indena SpA) combining quercetin with phosphatidylcholine in a 1:1 ratio — forming a phytosomal complex where quercetin is encapsulated in a phospholipid matrix that mimics intestinal cell membrane composition. This dramatically improves intestinal absorption by delivering quercetin to brush border cells in a membrane-compatible form, bypassing much of the normal quercetin bioavailability barrier.
Best-evidenced uses: Same as quercetin overall, but with proven superior plasma levels. Clinical applications where Quercefit has been specifically tested include: antioxidant status, cardiovascular biomarkers, sports performance recovery, and anti-inflammatory effects. Studies comparing Quercefit to plain quercetin consistently show ~20× higher plasma quercetin AUC.
Practical note: A 500 mg Quercefit dose delivers systemically accessible quercetin comparable to ~10,000 mg of plain quercetin — making it substantially more cost-effective for therapeutic purposes despite higher cost per gram. When quercetin RCTs fail to show effects, it is often due to using plain aglycone quercetin that never reaches therapeutic plasma levels. Quercefit ensures the dose delivered to tissues is therapeutically relevant.
What is Quercefit (Quercetin Phytosome)?
Phytosomal quercetin absorption: phosphatidylcholine binds quercetin and creates a lipid-compatible complex that is taken up by intestinal enterocytes via lipid transport pathways (similar to dietary fat absorption) rather than requiring quercetin to dissolve in aqueous gut contents (a major barrier for plain quercetin). The quercetin-PC complex is incorporated into micelles with bile acids and absorbed efficiently. Peak plasma quercetin with Quercefit is achieved faster and at much higher levels than plain quercetin.
Quercefit was developed and patented by Indena SpA (Milan), the same company that developed Meriva (curcumin phytosome) and other plant phytosomes. The pharmacokinetic comparison study showing 20× bioavailability improvement was published in 2019 (Riva et al.). It has since been incorporated into many premium supplement brands. Sports performance and anti-inflammatory clinical trials specifically using Quercefit have been conducted in Italy and the US.
Evidence-based benefits
1. Plasma quercetin levels (vs. plain quercetin)
Pharmacokinetic study shows Quercefit achieves ~20× higher AUC (area under the curve — total systemic exposure) compared to plain quercetin at the same dose. This is the foundational evidence establishing Quercefit's utility.
2. Sports performance and recovery
RCTs with Quercefit show faster muscle recovery, reduced oxidative stress markers, and improved endurance performance at doses of 500 mg/day — results not replicated with plain quercetin at equivalent doses.
3. Cardiovascular and anti-inflammatory markers
Clinical trials with Quercefit show improved flow-mediated dilation (FMD), reduced CRP and IL-6, and improved lipid profiles — consistent with the quercetin mechanisms that benefit from adequate plasma levels.
Supplement forms compared
| Form | Typical dose / Bioavailability | Best for | Notes |
|---|---|---|---|
| Quercefit (quercetin phytosome — 500 mg = 250 mg quercetin + 250 mg PC) | 250–500 mg Quercefit/day | All therapeutic quercetin applications — best bioavailability | Patented; 20× absorption. Best choice for therapeutic quercetin supplementation. |
| Compare: plain quercetin (aglycone) | 1,000–2,000 mg/day | Lower bioavailability — may need much higher dose | ~1% bioavailability; must use very high doses for comparable plasma levels. |
| Compare: isoquercetin (quercetin-3-glucoside) | 100–500 mg/day | Better than plain quercetin — good midpoint | More bioavailable than aglycone; less studied than Quercefit; cheaper. |
How much should you take?
- 250–500 mg Quercefit/day (providing 125–250 mg quercetin)
- Take with meals for fat-mediated absorption; phospholipid complex benefits from co-ingestion with dietary fat
Same safety profile as quercetin overall. Excellent safety record. CYP enzyme inhibition at high quercetin concentrations — less concern at therapeutic Quercefit doses (which achieve plasma levels, not simply taking higher crude doses). See full quercetin interaction details on the main Quercetin page.
Safety and side effects
Common side effects
- Same adverse effects as standard quercetin — see Quercetin page for details
- GI upset uncommon at therapeutic Quercefit doses
- CYP enzyme inhibition is proportional to plasma quercetin levels — monitor with polypharmacy
Serious risks
Same drug interactions as quercetin. At Quercefit's effective doses, plasma quercetin may reach levels sufficient to produce CYP3A4 and CYP2C9 interactions. See Quercetin page for full interaction list.
Drug and nutrient interactions
- Same drug interactions as quercetin — see Quercetin page
- Important note: plasma levels of quercetin are much higher with Quercefit than plain quercetin at equivalent mg doses — drug interactions may be more relevant with Quercefit than with plain quercetin
Check our free interaction checker for additional combinations.
Who might benefit — and who should use caution
| Most likely to benefit | Use with caution or seek guidance |
|---|---|
| Anyone using quercetin therapeutically who wants to ensure they're achieving effective plasma levels | Same populations as quercetin overall — see Quercetin page |
| Athletes wanting quercetin's anti-inflammatory and performance recovery benefits at practical doses | People on multiple medications — CYP interactions may be more relevant at Quercefit's effective plasma levels |
Frequently asked questions
Why is Quercefit better than plain quercetin?
Plain quercetin has approximately 1% oral bioavailability. Quercefit (quercetin phytosome) delivers the same quercetin molecule in a phosphatidylcholine complex that is absorbed through lipid transport pathways, achieving ~20× higher plasma levels. This means 250–500 mg Quercefit delivers comparable systemic quercetin to 5,000–10,000 mg of plain quercetin — at much lower doses, cost, and with fewer GI effects.
Is Quercefit the same as Meriva?
Quercefit and Meriva are both phytosomes made by Indena SpA, but they contain different botanical compounds. Quercefit = quercetin + phosphatidylcholine. Meriva = curcumin + phosphatidylcholine. Both use the same phytosome technology to improve bioavailability. They can be combined for complementary anti-inflammatory applications.
See the main Quercetin page for complete FAQ and evidence review.
For full clinical evidence, forms comparison, and drug interactions — see the Quercetin review page.
Related ingredients
Quercetin (Full Review)
Complete evidence review with all clinical trials, FAQ, and interactions.
Fisetin
Related senolytic flavonoid; often combined with quercetin for synergistic senolytic and anti-inflammatory effects.
Curcumin Phytosome (Meriva)
Another Indena phytosome with similar bioavailability enhancement for curcumin.
Disclaimer: This information is for educational purposes only and should not replace medical advice. Always consult a qualified healthcare provider before starting any supplement, especially if you have a medical condition, are pregnant, or take prescription medications. These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.