Thorne is seeking eligible and interested adult volunteers for a 90-day research study that will evaluate the effects of quercetin on metabolic wellness. 

Who is eligible?

We need 40 men and women, ages 20-70, who currently have high-normal LDL cholesterol (130-159 mg/dL) but are not taking a statin nor any other lipid-lowering medication or supplement and who meet two or more of the following criteria:

  • Low-normal fasting High-Density Lipoprotein (HDL < 50 mg/dL)
  • High-normal fasting Triglycerides (TG 150-199 mg/dL)
  • High fasting Blood Sugar (Glucose 100 – 126 mg/dL)
  • Waist Circumference > 40 in for men or > 35 in for women 

You are not eligible if you are pregnant or nursing, if you are being treated for high blood pressure, if you have been diagnosed with metabolic syndrome, or if you have a medical history that includes high blood pressure, heart disease, or you are currently taking any of these supplements regularly:  Quercetin, Berberine, Red Yeast Rice, Fish Oil, Bergamot Juice Extract, Pantethine, Vitamin D3 (more than 5,000 IU daily), Pterostilbene, Aged Garlic, Phytosterols, Niacin (crystalline/acid, not niacinamide), and Meriva/curcumin/turmeric.

We are not able to enroll individuals who live in New York, New Jersey, Rhode Island, Maryland, North Dakota, South Dakota, or Hawaii. 

What can I expect?

Before getting started, those who are interested will complete a screening questionnaire, and, if still qualified, will conduct a telephone interview with a study doctor to discuss further eligibility requirements and answer several additional questions before signing the study’s consent form. 

Participants will be asked to not significantly change their lifestyle during the 90-day study.  We will initially ask and continue to follow-up that you are maintaining the same exercise regimen, dietary intake, sleep patterns, stress levels, and that you are taking only the study supplement and whatever else a participant has been approved to continue taking.  Participants will be asked to agree to communicate with the study coordinator via email or telephone and not be traveling during two blood-draw time periods.  We anticipate the 90-day study beginning as early as March and ending as late as August 2022.  

At the beginning and the end of the 90-day study, participants will make two fasted visits to their local Quest Diagnostics laboratory for a blood draw.  Between the two blood draws, all subjects will take one capsule of Thorne’s Quercetin Phytosome supplement three times daily (750 mg daily total), with meals for 90 days. Participants will also complete eight online questionnaires, approximately one every other week.  The Quercetin Phytosome supplement will be mailed to a participant’s home.  All testing will be paid for by the study.  We estimate the total time commitment to be about four hours throughout the study. 

What is Quercetin Phytosome?

Quercetin is a natural compound primarily found in vegetables, fruits, and nuts. Indena S.p.A. has developed a unique formulation of quercetin, their proprietary phytosome complex called Quercefit®, which the human body absorbs very efficiently.  Quercefit® has been demonstrated to safely provide a 20-times higher blood level of quercetin than non-phytosome quercetin. Thorne uses Quercefit® in its Quercetin Phytosome product – the supplement being tested in this study.

What are the outcome measures?

Our study will look for statistical differences in the biomarkers obtained from the two blood draws and responses to the eight questionnaires.  The blood draws will be analyzed for a complete metabolic panel, CBC with differential, lipid panel, lipid subfractions, DHEA-s and hemoglobin A1C.

What are the benefits of participating?

We anticipate minimal risk from the two blood draws and the supplement intervention. Participants will have access to the study team for questions and a 24/7 phone number for any concerns.  Individuals who complete the study will receive the results of their two blood draws, the free 90-day supply of Quercetin Phytosome, and $100 in Amazon gift cards.

Participation is voluntary and a participant can withdraw with no consequences at any time.  If you think you are eligible and you are interested in participating, then you can begin the screening questionnaire here, or email the Study Coordinator at with questions and to learn more!