Quercetin Phytosome (with Vitamin C)

Immunity & antioxidants

Function & benefits

A plant flavonoid found in onions and apples; it acts as an antioxidant, and laboratory studies suggest it stabilizes mast cells (moderating histamine release) and helps carry zinc across cell membranes.

Dosage & how to use

Recommended dose	250–500 mg phytosome (or 500–1000 mg quercetin dihydrate)
Best time to take	With a meal that contains healthy fats
Frequency	Once daily or in split doses

Best forms to choose

Quercetin phytosome bound to phospholipids (such as Quercefit®), absorbed up to 20 times better than raw powder.

Important warnings

Safe up to 1000 mg a day for 12 weeks

Continuous high doses are not advised with kidney failure

Best avoided during pregnancy and breastfeeding

Drug interactions

It inhibits CYP3A4 and P-gp, so it may raise blood levels of calcium channel blockers, ciclosporin and anticoagulants. It may interact with fluoroquinolone antibiotics.

View in the supplements guide

Related supplements

Scientific references

Andres S et al. Mol Nutr Food Res 2018 (safety of quercetin supplements) — PMID: 29127724

📚 Published sources and research: European Food Safety Authority (EFSA) • National Institutes of Health (NIH - ODS) • PubMed / Cochrane databases

Content last updated: 17 October 2026 · Based on published sources and research (EFSA / NIH / PubMed)

⚖️ Medical disclaimer: The information and data provided here are for health education and nutritional guidance only. They are not a medical diagnosis and never replace a direct consultation with your doctor or pharmacist. Always consult your doctor before starting any supplement, especially during pregnancy or breastfeeding or when taking long-term medication.