THORNE - Quercetin Phytosome - Antioxidant Supplement for Immune Health, Respiratory Support & Seasonal Allergy Relief* - Third-Party Certified - Gluten, Dairy & Soy-Free - 60 Capsules
$0.77/serving
Price verified Apr 22, 2026
Not evaluated by the FDA · Individual results may vary · Consult a healthcare provider before use
Our verdict
250mg quercetin phytosome per capsule of Quercetin Phytosome (Quercefit) per capsule from THORNE. Best for overall — best absorption via phytosome technology with NSF certification.
Why we recommend this
Thorne uses Quercefit, the patented quercetin phytosome by Indena, which delivers up to 20x higher plasma levels than standard quercetin. At 250mg phytosome, this provides more bioavailable quercetin than 1000mg of standard quercetin dihydrate. NSF Certified for Sport is the highest tier of third-party testing. Thorne is trusted by professional athletes and healthcare practitioners.
Check for interactions
Already taking other supplements or prescription medications? Add them below to check for documented interactions, severity, and clinical guidance.
Our database currently documents 137+ supplement and drug-category interaction pairs. Combinations not flagged here may still interact — always consult your healthcare provider before combining supplements, especially with prescription medications.
What to watch out for
Premium pricing. Lower "label dose" may confuse consumers who compare milligrams without understanding bioavailability.
Dose & form
- Serving
- 250mg quercetin phytosome per capsule
- Form
- Capsule
- Clinical range
- 500-1000mg daily
- Dose adequacy
- Subtherapeutic
- Supply
- 60 servings · $0.77/serving
- UPC
- 693749004356
Who it's best for
Overall — best absorption via phytosome technology with NSF certification
Who should skip it
Budget shoppers confused by lower milligram label dose
Pros
- 20x absorption vs standard quercetin
- NSF Certified for Sport
- Patented Quercefit technology
- Trusted by healthcare practitioners
Cons
- Premium price ($0.52/serving)
- 250mg label dose (despite superior absorption)
- Only 60 capsules per bottle
What customers say
4.7★ across 2,325 Amazon reviews. The most common questions from shoppers: thorne quercetin phytosome safe for daily use, i take thorne quercetin phytosome with other supplements, and thorne quercetin phytosome safe for athletes. Full answers in the FAQ below.
Frequently Asked Questions
What is the clinical dose for Quercetin Phytosome (Quercefit)?
What is the clinical dose for Quercetin Phytosome (Quercefit)?
Clinical trials typically use 500-1000mg daily. Thorne Quercetin Phytosome delivers 250mg quercetin phytosome per capsule, which we classify as Subtherapeutic relative to that range.
How does Thorne Quercetin Phytosome compare to similar Capsule?
How does Thorne Quercetin Phytosome compare to similar Capsule?
See the "Also consider" section below for two alternatives. Choose based on form preference (Capsule vs alternatives), dose adequacy, and third-party testing.
Is Thorne Quercetin Phytosome third-party tested?
Is Thorne Quercetin Phytosome third-party tested?
Yes — NSF Certified for Sport. Third-party testing verifies ingredient identity and label accuracy.
Does this work with Amazon Subscribe & Save?
Does this work with Amazon Subscribe & Save?
Yes — Amazon Subscribe & Save is available for this product. Enrolling locks in a recurring delivery at a reduced per-unit price.
Is Thorne Quercetin Phytosome safe for daily use?
Is Thorne Quercetin Phytosome safe for daily use?
Yes, Thorne Quercetin Phytosome is safe for daily use and is NSF Certified for Sport, the highest tier of third-party testing. Quercetin has been used in clinical trials for up to 12 weeks without significant adverse effects. Consult your doctor if you take medications, as quercetin may interact with certain drugs.
Can I take Thorne Quercetin Phytosome with other supplements?
Can I take Thorne Quercetin Phytosome with other supplements?
Yes, quercetin pairs well with vitamin C, zinc, and bromelain for enhanced immune and antioxidant support. The phytosome form already includes phospholipids for better absorption. Avoid taking it with certain antibiotics (fluoroquinolones) as quercetin may affect their absorption.
Is Thorne Quercetin Phytosome safe for athletes?
Is Thorne Quercetin Phytosome safe for athletes?
Yes, it is NSF Certified for Sport, meaning it has been tested for over 270 banned substances and is safe for competitive athletes. Thorne is the official supplement partner of many professional sports teams and the US Olympic team.
Are there side effects from quercetin phytosome?
Are there side effects from quercetin phytosome?
Quercetin phytosome is generally well-tolerated. Rare side effects include mild headache or stomach upset. The phytosome delivery may reduce GI-related side effects compared to standard quercetin, as it requires a lower total dose for equivalent blood levels.
Can Thorne Quercetin Phytosome be taken during pregnancy?
Can Thorne Quercetin Phytosome be taken during pregnancy?
There is insufficient safety data on quercetin supplementation during pregnancy or breastfeeding. While quercetin is naturally present in foods like onions and apples, concentrated supplemental doses have not been studied in pregnant women. Consult your obstetrician before use.
What is the recommended dose of Thorne Quercetin Phytosome?
What is the recommended dose of Thorne Quercetin Phytosome?
The recommended dose is 1 capsule (250mg quercetin phytosome) once or twice daily. Due to the 20x improved absorption of phytosome technology, 250mg provides more bioavailable quercetin than 1,000mg of standard quercetin dihydrate.
Also consider
Part of this guide
Best Quercetin Supplements→