- Are you considering including a quercetin supplement in your diet?
- Do all quercetin supplements work the same to support health?
- Which quercetin supplement formula is the most effective?
Quercetin has been traditionally used across different cultures for its recognized health benefits. Its presence in various fruits, vegetables, and other common food sources makes it an inseparable component of a healthy diet. So why would you need a quercetin supplement? Read on to learn everything about this plant-derived compound as a supplement and how it can support your health and wellness. Use the links below to jump to specific related topics on the page.
The Basics of Quercetin
Quercetin is a flavonoid — a class of phytonutrients found naturally in various fruits and vegetables that are known to resist free radicals in the body. Quercetin and its derivatives do this by exerting their biological activity on cell cycle progression and signaling pathways.* The antioxidant properties of quercetin and its role in maintaining the body’s natural inflammatory response make it a novel nutritional supplement that supports various health functions.* Quercetin is abundant in a variety of foods, including berries, apples, grapes, tomatoes, onions, shallots, cruciferous vegetables, nuts, seeds, and tea. The estimated flavonoid intake in a healthy diet is 50 – 800 mg/day (quercetin accounts for 75%). However, because the dietary intake of quercetin varies, a quercetin supplement helps fill the nutritional gaps, if any.
Quercetin is a flavonoid — a class of phytonutrients found naturally in various fruits and vegetables that are known to resist free radicals in the body. Quercetin and its derivatives do this by exerting their biological activity on cell cycle progression and signaling pathways.* The antioxidant properties of quercetin and its role in maintaining the body’s natural inflammatory response make it a novel nutritional supplement that supports various health functions.*
Quercetin is abundant in a variety of foods, including berries, apples, grapes, tomatoes, onions, shallots, cruciferous vegetables, nuts, seeds, and tea. The estimated flavonoid intake in a healthy diet is 50 – 800 mg/day (quercetin accounts for 75%). However, because the dietary intake of quercetin varies, a quercetin supplement helps fill the nutritional gaps, if any.
Quercetin accounts for 75% of daily estimated flavonoid intake in a balanced diet
Health Benefits of Quercetin
Research1 has established that quercetin exerts beneficial antioxidant effects on the body through:
- Maintaining the level of glutathione*
- Inhibiting the activity of the enzymes acetylcholinesterase (AChE) and butyrylcholinesterase (BChE)* to exert neuroprotective effects.
- Enhancing the expression of the body’s natural antioxidant enzymes*
- Supporting antioxidant signaling pathways*
Quercetin’s immunomodulatory effects2 are attributed to its role in:
- Inhibiting the production of cytokines, proteins that can cause the over-expression of other immune cells*
- Maintaining both the stability of mast cells while suppressing their activation*
- Inhibiting the release of enzyme beta-glucuronidase from leukocytes*
- Targeting intracellular signaling kinases, phosphatases, enzymes, and other membrane proteins*
The beneficial antioxidant and immunomodulatory effects of quercetin contribute to its immense therapeutic potential to promote sleep, cardiovascular health, renal health, immune health, and skin health.*
| How Does Berberine Support Endocrine Health? | |
| Health Function | Therapeutic Applications |
| Heart* | |
| Kidney* | |
| Immune Function* | |
| Skin* | |
| Brain* | |
| Gastrointestinal System* | |
Formulated versus Unformulated Quercetin
Quercetin is available in different forms — as glycoside, sulfate, glucuronide, and methylated quercetin. Chemically, free quercetin (C15H10O7) lacks an attached sugar or glycosyl group. The attachment of a glycosyl group to quercetin glucoside makes it more soluble in water and enhances its absorption. Nutritional quercetin in plant sources is mainly present in the form of glycoside.
Although quercetin glucoside is relatively more soluble than other quercetin forms, its bioavailability is still relatively low.
The estimated absorption of quercetin glucoside ranges from 3% – 17% in healthy individuals.3
The relatively poor absorption and bioavailability of quercetin is addressed through quercetin formulations that can enhance its bioefficacy. The following table highlights the difference between the efficacy of formulated versus unformulated quercetin.
| Formulated versus Unformulated Quercetin |
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Types of Quercetin Nutrition Supplements
Quercetin supplements are commercially available in oral, intravenous, intranasal, and topical forms. The different delivery routes of quercetin intake are intended to maximize its absorption in the body. The following table highlights the types of quercetin nutrition supplements and their applications
| Types of Quercetin Supplements | |||
| Oral | Intravenous | Intranasal | Topical |
| Available in powder, tablet, and capsule forms. | Available in IV drip form. | Available in nasal spray and liquid drop form. | Available in gel, ointment, cream, and lotion form. |
| Used to support multiple health functions, including cardiovascular health and immune health.* | Used to modulate mast cell activation and address adverse immune responses. | Used to limit the release of histamine from immune cells to maintain a natural inflammatory response. | Used to address inflammation associated with bruises, wounds, and swelling. |
Common Absorption Challenges of Quercetin Supplements
Nutrient delivery systems for quercetin supplements are designed to enclose a significant amount of the compound to protect it against chemical degradation during processing and storage and release it at a controlled rate and in a particular region of the gastrointestinal tract. Many forms of quercetin supplements are ineffective at doing this due to the following:
- Poor absorption: Quercetin glycosides are absorbed differently based on the type of attached sugar group. Quercetin undergoes rapid metabolism in the body, with major absorption in the upper segment of the small intestine and only minor amounts absorbed in the stomach.
- Compromised bioavailability: The chemical structure and physico-chemical properties of quercetin influence its water solubility and chemical stability. The resulting rapid metabolism and enzymatic degradation of quercetin in the liver, small intestine, colon, and kidney results in its poor bioavailability.
Innovative Quercetin Nanoformulations
Innovative approaches to increase the bioavailability of quercetin aim to limit its hydrophobicity. Several nanoformulations overcome quercetin’s poor bioavailability by enhancing its absorption at the desired site of action. Some of the common nano-delivery technologies that can enhance quercetin’s bioavailability include:
- Lipid nanoparticles
- Liposomes
- Polymeric nanoparticles
- Silica nanoparticles
- Cyclodextrins
- Magnetic nanoparticles
- Gold nanoparticles
FAQs: Frequently Asked Questions About Quercetin Supplements
How much quercetin should I take daily?
Research5 show that quercetin intake up to 500 mg twice a day for 12 weeks has mild to no symptoms of overdose. However, the appropriate daily use of quercetin on specific health needs should be determined by consulting with your healthcare provider to determine the best daily quercetin usage for you.
Are there side effects from taking a quercetin supplement?
Although quercetin is generally considered safe and adverse side effects are rarely reported, the effects of its intake at or above one gram daily for longer than 12 weeks are yet to be determined.
Can I take a quercetin supplement with a prescription medication?
A quercetin supplement might interact with certain medications. Consult with your healthcare practitioner to know more about potential contraindications before including a quercetin supplement in your diet or taking it with a prescription medication.
How do I determine the efficacy of a quercetin supplement?
The enhanced bioavailability of quercetin enables it to have increased absorption in the body. Tesseract Medical Research’s QuerciSorb Immuphore SR® is an innovative nanoformulated quercetin supplement that contains other nutrients, including vitamin C, vitamin D, and zinc, to support immune health.* Tesseract’s QuerciSorb® – SR/QR is another supplement nanoformulation that features bioactive quercetin to promote cardiovascular health.* Both supplements are formulated using Tesseract’s proprietary CyLoc® – DexKey® nutrient delivery nanotechnology, which enhancessolubility and absorption to release individual quercetin molecules throughout the intestinal tract for optimal bioavailability. The result is maximum absorption and effectiveness for each quercetin molecule, making quercetin’s use a bioavailable therapeutic reality to support your good health and wellness.*
The power of Tesseract nutritional supplements lies in enhancing palatability, maximizing bioavailability and absorption, and micro-dosing of multiple nutrients in a single, highly effective capsule. Visit our website for more information about how Tesseract’s products can support your cardiovascular health.*
The power of Tesseract nutritional supplements lies in enhancing palatability, maximizing bioavailability and absorption, and micro-dosing of multiple nutrients in a single, highly effective capsule. Visit our website for more information about how Tesseract’s products can support your cardiovascular health
Citations
1Richie JP Jr, Nichenametla S, Neidig W, et al. Eur J Nutr 2015 Mar;54(2):251-263. doi: 10.1007/s00394-014-0706-z. Epub 2014 May 5. PMID: 24791752.
2Sinha R, Sinha I, Calcagnotto A, et al. Eur J Clin Nutr 2018 Jan;72(1):105-111. doi: 10.1038/ejcn.2017.132. Epub 2017 Aug 30. PMID: 28853742; PMCID: PMC6389332.
3Mischley LK, Vespignani MF, Finnell JS. J Altern Complement Med 2013 May;19(5):459-463. doi: 10.1089/acm.2011.0673. Epub 2012 Dec 16. PMID: 23240940; PMCID: PMC3651682.
