Quercetin Phytosome is one of the supplements I reach for most often when someone needs immune balance and antioxidant support. Quercetin is a plant bioflavonoid found in onions and the colored skins of fruits and vegetables, and in my practice it is a workhorse for supporting healthy histamine levels and a balanced inflammatory response.

The reason I like this specific product is absorption. Plain quercetin is poorly absorbed from the gut. Thorne binds it to fat-based phospholipids from sunflower, which the manufacturer notes can make it up to 20 times more absorbable than standard quercetin extracts. Better absorption means less product is needed to get where it is going.

I use quercetin most often for people working on healthy histamine balance and mast cell support, seasonal immune support, and cytokine balance within a full regimen. The lab research here is encouraging. Published studies show quercetin inhibits mast cell degranulation and reduces histamine release in cell and animal models, and a broad review paper documents its antioxidant and inflammation-regulating properties.

Much of this science findings are from test tube and animal work, not large human trials, so I treat quercetin as a support tool. It works best as part of a coordinated plan.

Dosing in my practice is 1 to 2 capsules two to three times daily with meals. It is well tolerated by most, though some people report headaches with flavonoids like this. Anyone who is pregnant, nursing, or taking prescription medication should review it with their health care practitioner first.