Phytotherapy

Quercetin

Flavonol

Mechanism

Quercetin is a widespread flavonol (plant pigment) that is markedly antioxidant in vitro and shows inflammation-modulating effects; from this the traditional use to support antioxidant status is derived. The limiting factor is its low oral bioavailability: quercetin undergoes pronounced first-pass metabolism (glucuronidation, sulfation, methylation) in the intestinal mucosa and liver, so only little unchanged quercetin reaches the circulation. In the horse too, quercetin is in principle orally absorbable, but the plasma metabolite pattern is species-specific and the plasma levels reached after two weeks of supplementation are only moderate. Equine studies on clinical endpoints (beyond plasma/pharmacokinetics) are largely lacking.

Cautions

· Low oral bioavailability (strong first-pass metabolism) — high doses are usually unnecessary
· Equine endpoint evidence is thin; existing horse data concern mainly pharmacokinetics/plasma levels

Sources

Wein & Wolffram 2013Wein & Wolffram, J Equine Vet Sci — Oral Bioavailability of Quercetin in Horses

Reszka et al. 2015Reszka et al., J Equine Vet Sci — zweiwöchige Quercetin-Supplementierung führt zu moderater Akkumulation der Plasma-Flavonolspiegel beim Pferd

Equiterna Score

59/100

solid

Science4.5/10

Practical experience6/10

Safety7.8/10

Overall score scale

high overall75–100solid55–74limited0–54

How the Equiterna Score is built

The Equiterna Score combines three dimensions into a value of 0-100: science (40%), practical experience (30%) and safety (30%). It is transparently derived from evidence level, attributed sources (PubMed/journals), legal classification and cautions. The FEI doping status is shown separately as a competition-law note and does not enter the score. Commissions and vendor relationships have no influence on the score. In addition, the editorial safety rating caps the result: it limits the safety dimension and the overall tier (orange: at most solid). For entries rated red, no score is calculated at all. The rating never raises anything — a green rating does not lift a calculated value.

An editorial assessment of the evidence and safety situation — not a healing claim and not an individual recommendation. It does not replace veterinary advice.

Dosageproduct-specific; equine studies used approx. 5–10 mg/kg BW/day — higher doses bring no proven additional benefit because of limited bioavailability

AMG statusComplementary feed

FEI statusNot listed

SafetyVery safe

Evidenceemerging

Frequently asked questions

Is Quercetin a feed or a veterinary medicine for horses?

Equiterna classes Quercetin as “Complementary feed”. Legal framework: Regulation (EU) 2019/6 / TAMG (DE/AT), Feed Regulation (EC) 767/2009.

Is Quercetin allowed at FEI competitions?

In the profile, Quercetin is listed with the FEI status “Not listed”. The current FEI list is authoritative, so please check its latest version.

Which dosage do the sources give for Quercetin?

Stated in the profile: product-specific; equine studies used approx. 5–10 mg/kg BW/day — higher doses bring no proven additional benefit because of limited bioavailability. This is information from the literature, not an instruction for an individual horse.

Which sources are there for Quercetin?

The profile cites: Wein & Wolffram 2013 and Reszka et al. 2015.

Usage note

This content is for information and education. It does not replace veterinary diagnosis or treatment. If your horse shows signs of illness, consult a veterinarian.

“Nothing forced can ever be beautiful.”

Xenophon · On Horsemanship (c. 365 BC)

Equiterna is an intermediary platform for equine knowledge, marketplace and tools — not a veterinary-medicines dealer, veterinary practice or pharmacy. Compound information is source-attributed (PubMed, specialist journals, NRC/GfE, EU regulations) and free of healing claims. Legal framework: Regulation (EU) 2019/6 / TAMG (DE/AT), Feed Regulation (EC) 767/2009, FEI Prohibited Substances List, HWG.

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