Quercetin
Of 2,238 on-market quercetin products in the January 2026 DSLD dump, the median declared dose is 100 mg, and 99.0% list Quercetin Dihydrate as the primary form.
Form share
Of 2,214 products with an identifiable primary form, here is the share held by each form of Quercetin on the market today.
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| Form | Quality tier | n | Share |
|---|---|---|---|
| Quercetin Dihydrate | Tier 2 | 2,191 | 99.0% |
| Sophora japonica / Dimorphandra mollis extract (source-plant labeling) | Unrated | 23 | 1.0% |
Forms we recognize but found no primary-form products for in this release: Quercetin Phytosome (lecithin-complexed).
Form share over time
Entry-year breakdown of the top forms, 2012–2025.
Dose distribution
Deciles of declared dose per serving (mg), among 1,524 products with a disclosed amount.
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- 13.0% of products fall below the fairy-dust threshold (20 mg, 20% of the studied low dose).
- 31.3% of products don't disclose an amount because Quercetin is declared inside a proprietary blend.
Where does your dose rank?
Enter a per-serving dose (mg) to see exactly how it compares to the 1,524 on-market quercetin products with a disclosed amount. The chart above groups doses into deciles; this looks up the exact percentile for one number.
By dosage form
By target group
Top brands
Search interest over time
How often people search for quercetin on Google, US only, the last 5 years. This is public interest, not DSLD label data — a spike here doesn't necessarily line up with anything on this page, and Google's own index (100 = that term's peak popularity in the chosen window) is relative, not an absolute search-volume count.
Or see this search directly on trends.google.com.
Forms explained
Standard unformulated quercetin (aglycone/dihydrate) used in most human RCTs; documented poor solubility and oral absorption (Riva 2019).
Source: Serban MC et al. 2016, J Am Heart Assoc 5(7):e002713, PMID 27405810; Riva A et al. 2019, PMID 30328058
Compared against unformulated quercetin in one 12-subject crossover PK study (Riva 2019, authored by employees of the Phytosome manufacturer), with up to ~20-fold higher plasma exposure; no clinical-outcome trials of this form versus standard quercetin are cited.
Source: Riva A et al. 2019, Eur J Drug Metab Pharmacokinet 44(2):169-177, PMID 30328058
Raw-material source descriptors, not a functionally distinct delivery form -- insufficient evidence they differ from generic quercetin dihydrate/aglycone once standardized.
Source: none (definitional)
Reference values
- RDA (adult): not established — Plant-derived flavonoid, not an essential nutrient; no DRI exists.
- Tolerable Upper Intake Level (adult): not established — Not established -- no IOM/NASEM UL exists. Trials up to ~1000mg/day for weeks have not reported serious adverse effects, but this is not a formal UL.
- Studied clinical dose range: 100–1000 mg
- Serban MC et al. 2016, J Am Heart Assoc 5(7):e002713, PMID 27405810 -- meta-analysis of 7 RCTs (587 patients) at 100-1000mg/day for 4-10 weeks; significant blood-pressure reduction in the >=500mg/day subgroup but not the <500mg/day subgroup, although the between-subgroup difference was not significant.