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Polyphenol / Senolytic-adjacent

Quercetin Phytosome · Quercetin complexed with sunflower phospholipids (lecithin delivery system)

A lecithin-bound quercetin form built to fix quercetin's biggest problem: almost none of a standard dose reaches the blood.

B
Evidence grade
Human RCTs, biomarker outcomes

Short answer

If you are taking quercetin specifically for absorption-dependent effects, the phytosome form has real human pharmacokinetic data behind it. Regular quercetin is fine for general polyphenol intake at a lower cost.

Product and dose overview

Quercetin Phytosome (Quercetin complexed with sunflower phospholipids (lecithin delivery system)) is a polyphenol / senolytic-adjacent with evidence grade B, meaning it is supported by human RCTs. We track 1 products containing Quercetin Phytosome. Typical doses range from 25 to 25 mg per serving. The top-ranked product scores 5.7 out of 10 on our composite scale (dose, evidence, price, testing, transparency). Prices range up to $19.89 per month.

Evidence grade: B Products in database: 1 Category: Polyphenol / Senolytic-adjacent

Top Quercetin Phytosome products

ProductBrandDosePrice/mo3rd-party testedScore
Senolytic ActivatorLife Extension25 mg$19.89Yes5.7

Scores are editorial judgments, not a scientific standard. See how we score.

What it is

Regular quercetin dissolves poorly and most of a dose never gets absorbed. This version wraps quercetin in a phospholipid shell, the same kind of fat molecule that makes up cell membranes, so more of it survives digestion and enters circulation.

Why people take it

A human crossover trial found the phytosome form reached plasma levels up to 20 times higher than the same dose of plain quercetin, with no notable side effects. Quercetin itself is one of the two compounds in the original Mayo Clinic senolytic combination (with dasatinib), so a better-absorbed form matters for anyone using it for that purpose.

Our verdict

If you are taking quercetin specifically for absorption-dependent effects, the phytosome form has real human pharmacokinetic data behind it. Regular quercetin is fine for general polyphenol intake at a lower cost.

Structure & class

Quercetin aglycone complexed 1:1 by weight with food-grade sunflower lecithin (phosphatidylcholine), commercialised as Quercetin Phytosome / Quercefit (Indena). Standardised to roughly 40% quercetin by weight.

Mechanism & clinical data

Riva et al. 2018 (crossover PK study, n=12) measured a Cmax about 20-fold and an AUC about 18-fold higher for Quercetin Phytosome versus unformulated quercetin at matched doses. The mechanism is improved GI solubility and enterocyte membrane permeability from the phospholipid carrier, not a change to quercetin itself.

Pharmacokinetics

Not separately characterised from quercetin; absorption profile studied over 24 hours in the pharmacokinetic trial.

Dose & forms

Trial dose
250 mg
/ day
Range in trials
250 to 500 mg
/ day
Common forms
Quercetin Phytosome / Quercefit® (Indena)

What to watch out for

The 20-fold bioavailability data is specific to the branded phytosome form studied by Riva et al.; it should not be assumed for other enhanced quercetin blends without their own pharmacokinetic data. No head-to-head trial yet compares clinical outcomes (not just blood levels) between phytosome and standard quercetin.

Where this dose comes from

The trial dose above is our editorial pick from the published human trials for this ingredient. We choose the dose that the best-available studies used on the endpoint most relevant to longevity. The range shows the lowest and highest doses tested in published trials. The landmark studies below are the papers we read to set it. You can click through and check our work.

When new trials publish, our automated sweeps flag them. If a new study materially changes the dose, we update it through editorial review and record the old dose, new dose, and the triggering study in every affected product's recommendation history. The dose is never changed automatically.

Regulatory status

EUFood supplement
USDietary supplement
UKFood supplement
CANHP

Timeline

Regulatory events, evidence grade changes, and key research milestones for Quercetin Phytosome, most recent first. Studies link to the paper; regulatory entries name and link the responsible authority.

  • 2025-04 Regulatory single source
    EU Court sharpens the bar for botanical health claims
    A Court of Justice of the European Union ruling in April 2025 further tightened the requirements for how botanical ingredients (herbs, plant extracts) can be marketed with health claims in the EU, effectively removing much of the flexibility of the on-hold list.
  • 2024-06 Regulatory confirmed
    EU report identifies 117 supplement substances as potential health risks
    The HoA Working Group on Food Supplements (26 European countries) published its first report evaluating 117 substances used in food supplements. Of these, 65 were assessed as likely novel foods, 6 were already regulated, 34 had insufficient data, and 12 were prioritized for Article 8 restriction under Regulation (EC) No 1925/2006. The 12 priority substances include ashwagandha, curcumin, melatonin, piperine, St. John's wort, coumarin, p-synephrine, maca, holy basil, Melaleuca, black cohosh, and L-tryptophan. The report drew on 1,500 RASFF alerts reviewed between 2017 and mid-2022.
    Source →
  • 2018 Research milestone
    Riva et al. 2018
    Quercetin Phytosome reached plasma quercetin levels up to 20-fold higher than unformulated quercetin at matched doses in a human crossover trial.
    Source →
  • 2006-12 Regulatory confirmed
    EU Health Claims Regulation adopted
    Regulation (EC) No 1924/2006 laid down harmonised rules for nutrition and health claims made on foods, including supplements. Only claims listed in the EU Register of authorised claims can be used. Rejected botanical claims are held in a separate on-hold list.
    Source →
  • 1997 Regulatory confirmed
    EU introduces the Novel Food Regulation
    Regulation (EC) No 258/97 required any food or food ingredient without a history of consumption in the EU before 15 May 1997 to be authorised before being placed on the market. This is the framework that captures NMN, spermidine as a supplement ingredient, urolithin A, and many other longevity actives.
    Source →

Landmark studies

Found in these products (1)

All products in our catalog that contain Quercetin Phytosome, ranked by our overall score. Ranking is editorial, never paid.

Life Extension
Senolytic Activator
Autophagy
Ingredients listed
3 ingredients listedlargest listed: Fisetin 312 mg
Price per serving
$1.66$19.89 · 12 servings
Testing
3rd-party listed · no public lab certificate

Multi-ingredient bundle

Status as recorded in the catalog from brand materials; not independently verified by NO1GEVITY.

Score & research context 5.7/10

Editorial score, not proof that this product works. Research-dose calculations are not dosing advice.

100%
of trial dose
$2.66
per research-dose day, not label serving
0Trial dose2×
Catalog price · Confirm current price with www.lifeextension.com
Editorial guides

Buying guides and comparisons

Neighbouring molecules

Related ingredients

See all in Polyphenol / Senolytic-adjacent →

Molecules in the same class, plus the actives most often formulated alongside Quercetin Phytosome in our catalogue.

FisetinCstacked together in 1 productApigeninDstacked together in 1 product
Product shelves
See all in Autophagy (1)

See Quercetin Phytosome in context: the mechanism it acts through, the biomarker it moves, the products that dose it, and the trials that tested it.

View Quercetin Phytosome on the Longevity Map →

Frequently asked questions

What is Quercetin Phytosome?

Regular quercetin dissolves poorly and most of a dose never gets absorbed. This version wraps quercetin in a phospholipid shell, the same kind of fat molecule that makes up cell membranes, so more of it survives digestion and enters circulation.

What dose of Quercetin Phytosome should I take?

The trial dose in published human studies is 250 mg per day, with a range of 250 to 500 mg per day. Always consult a qualified clinician before starting any supplement.

Is Quercetin Phytosome safe?

The 20-fold bioavailability data is specific to the branded phytosome form studied by Riva et al.; it should not be assumed for other enhanced quercetin blends without their own pharmacokinetic data. No head-to-head trial yet compares clinical outcomes (not just blood levels) between phytosome and standard quercetin.

What is the best Quercetin Phytosome supplement?

We track 1 products containing Quercetin Phytosome. The top-ranked product scores 5.7 out of 10 on our composite scale, which evaluates dose, evidence, price, third-party testing, and transparency. See the comparison table above. Scores are editorial judgments, not a scientific standard.

What is the evidence grade for Quercetin Phytosome?

Quercetin Phytosome has evidence grade B, meaning it is supported by human RCTs. Grade A means replicated human RCTs with hard endpoints. Grade B means human RCTs with biomarker outcomes. Grade C means mixed or small human trials. See our evidence grading methodology.

Independently checked

Data verification

Evidence grade
B
Human RCTs, biomarker outcomes
Research dose
250 mg
Products tracked
1
Updated continuously
Safety signal
The 20-fold bioavailability data is specific to the brand...

Evidence grades are reviewed when new human RCTs are published. Product counts update automatically as new products are added. Dose ranges reflect published trial data, not brand recommendations. Read how we verify.