Quercetin

• For the temporary relief of hay fever, runny nose and congestion, itching eyes, occasional headache, or fatigue due to sensitivity to phenolic compounds found in foods or other products.*ICD-10: R51.9

DIRECTIONS Place drops under tongue 30 minutes before/after meals. Adults and children 12 years and over: Take 10 drops up to 3 times per day. Consult a physician for use in children under 12 years of age.

In case of overdose, get medical help or contact a poison control center right away. Keep out of the reach of children. If pregnant or breastfeeding, ask a healthcare professional before use.

1. 1Fatigue17014%
2. 2Drug Ineffective927.8%
3. 3Headache917.7%
4. 4Nausea796.7%
5. 5Diarrhoea786.6%
6. 6Dizziness776.5%
7. 7Off Label Use776.5%
8. 8Arthralgia665.6%
9. 9Pruritus645.4%
10. 10Dyspnoea615.2%
11. 11Pain595.0%
12. 12Covid-19544.6%
13. 13Rash534.5%
14. 14Asthenia484.1%
15. 15Anxiety474.0%

Recent PubMed references pinned to Quercetin as a MeSH major topic. Citations link to pubmed.ncbi.nlm.nih.gov.

• Quercetin and Nephrotoxicity: A Narrative Review of Cellular Pathways and Therapeutic Possibilities.
  Journal of biochemical and molecular toxicology · 2026 · Yazdanpanah Z, Sobhani H, Navabi M, et al.
  PMID 42257475DOI 10.1002/jbt.70927
• Quercetin Ameliorates Renal Fibrosis via SIRT5 in Diabetic Nephropathy.
  Iranian journal of kidney diseases · 2025 · Ma G, Xu Z, Zhang Y, et al.
  PMID 42234876
• Quercetin as a multi-targeted therapeutic candidate in oral cancers: molecular mechanisms and preclinical evidence.
  Molecular biology reports · 2026 · Abuhassan Q, Allela OQB, Alkhazali WH, et al.
  PMID 42234050DOI 10.1007/s11033-026-12041-0
• Quercetin regulates lipid metabolism and inflammatory microenvironment of microglia after spinal cord injury through activating the butyrate-FFAR2/AMPK/TFEB gut-brain axis signaling pathway.
  International immunopharmacology · 2026 · Zhou W, Wang S, Hong S, et al.
  PMID 42217340DOI 10.1016/j.intimp.2026.116928
• Quercetin Alleviates Postoperative Cognitive Dysfunction of Aged Mice by Regulating Microglial Polarization through Inducing miR-379-5p RNA Modification.
  Molecular neurobiology · 2026 · Li SR, Wang L, Li YW, et al.
  PMID 42209865DOI 10.1007/s12035-026-05957-y
• Exogenous Quercetin Enhances Salt Tolerance in Apocynum venetum Seedlings: Insights From Physiology and Transcriptomic Regulation.
  Physiologia plantarum · 2026 · Zhao X, Buttar ZA, Zhao B, et al.
  PMID 42206944DOI 10.1111/ppl.70939
• Co-administration of quercetin and NLRP3 inhibitor attenuates inflammation and oxidative stress in cuprizone-induced demyelination model.
  Brain research bulletin · 2026 · Nourmohammadi F, Javan A, Shirzad M, et al.
  PMID 42203077DOI 10.1016/j.brainresbull.2026.111967
• Enhancing Quercetin Bioavailability Attenuates Aging Phenotypes via the Gut Microbiota-Intestinal Barrier Axis in Aged Mice.
  Nutrients · 2026 · Naito Y, Mizushima K, Inoue R, et al.
  PMID 42196996DOI 10.3390/nu18101537

The 10 most recently updated of 130 ClinicalTrials.gov registrations naming Quercetin as an intervention. Registration is not evidence of efficacy or safety — reference crosswalk only.

• Quercetin Dyskeratosis Congenita (DC)/Telomere Biology Disorders (TBD)
  Recruiting · Phase 1 · Interventional · 12 enrolled · Children's Hospital Medical Center, Cincinnati
  NCT07628972updated 2026-06-05
• Investigating the Use of Quercetin on Glucose Absorption in Obesity, and Obesity With Type 2 Diabetes
  Completed · Phase 2 · Interventional · 24 enrolled · National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
  NCT00065676updated 2026-06-05
• Inhibition of HBV Replication and Biological Reversal of Cirrhosis (F3-F4) and HCC by Flavonoids
  Completed · Phase 4 · Interventional · 134 enrolled · Trieu, Nguyen Thi, M.D.
  NCT07084948updated 2026-06-05
• Improving Physical Ability and Cellular Senescence Elimination in HIV
  Active not recruiting · Phase 2 · Interventional · 82 enrolled · National Institute of Allergy and Infectious Diseases (NIAID)
  NCT07144293updated 2026-06-02
• Supplementation With Sirtuin Activators in Women With Increased Body Weight
  Recruiting · Interventional · 120 enrolled · Poznan University of Life Sciences
  NCT07245979updated 2026-05-22
• Senescence in Chronic Kidney Disease
  Enrolling by invitation · Phase 2 · Interventional · 30 enrolled · Mayo Clinic
  NCT02848131updated 2026-05-19
• Senolytics to Improve Osteoporosis Therapy
  Active not recruiting · Phase 2 · Interventional · 120 enrolled · Odense University Hospital
  NCT06018467updated 2026-05-11
• A 56-Day Exploratory Study of NatureU® Mind Care BeautyU Caps on Skin Aging Parameters
  Completed · Interventional · 31 enrolled · OmniSolutions Laboratory Holdings Limited
  NCT07571629updated 2026-05-11
• Fortifying Healthy Behaviors, Optimizing Medical Therapies and Enhancing Cognitive Function in Older Adults-pilot Study
  Completed · Phase 2 · Interventional · 23 enrolled · Washington University School of Medicine
  NCT07000734updated 2026-05-05
• Palmitic Acid and Human Microvascular Function
  Not yet recruiting · Phase 2 · Interventional · 40 enrolled · Medical College of Wisconsin
  NCT06683534updated 2026-04-29

Frequently asked questions

What is Quercetin used for?

According to FDA labeling, Quercetin carries indications including: For the temporary relief of hay fever, runny nose and congestion, itching eyes, occasional headache, or fatigue due to sensitivity to phenolic compounds found in foods or other products.*. This is a reference summary of labeled uses, not medical advice or a treatment recommendation.