Quercetin is a flavonoid — a class of plant pigments displaying antioxidant effects and supporting the body’s natural response to inflammation (like curcumin, found in turmeric).* Quercetin is found in a wide range of fruits and vegetables, like apples, grapes, berries, tomatoes, shallots, onions, capers, seeds, and nuts, and in different plant parts, including bark, leaves, and flowers.
As an antioxidant that neutralizes free radicals and limits oxidative stress in the body, quercetin has immense therapeutic potential to benefit various health conditions, including those related to sleep.*
Many traditional East Asian cultures credit lotus leaf extract for its sleep-enhancing effects. Notably, the lotus leaf contains high levels of flavonoids — specifically, quercetin and its derivatives*
Below, we discuss some of the most frequently asked questions about quercetin, its therapeutic benefits in attenuating behavior caused by sleep deprivation, safety and tolerance levels, and its ingestion in supplement forms to support your overall health.*
Let’s look at some of the common questions that might come to mind when you consider supplementing with quercetin to improve your sleep.
Current research suggests the potential role of quercetin in modulating the sleep-wake cycle by activating GABA receptors — the chief inhibitory receptors for the central nervous system.* In an animal study1, quercetin limited brain oxidative stress induced by paradoxical sleep, or REM sleep deprivation, in mice.*
A diet rich in fruits, vegetables, nuts, and seeds can naturally enhance your quercetin intake. Quercetin supplements are also a suitable alternative for both oral ingestion and topical application. While oral ingestion of quercetin helps support the immune system, cardiovascular health, sleep regulation, and others, topical applications of quercetin are primarily aimed toward wound healing. It is recommended to consult with your healthcare practitioner before including a quercetin supplement in your diet or applying it topically.
Isolated quercetin as a nutritional supplement at 1000 mg/day3 is considered a safe usage. Among the published human intervention studies,4 adverse effects of quercetin supplementation have rarely been reported and any such adverse effects were mild in nature. However, it is worth noting that adequate published scientific data is not yet available to assess the safety of long-term usage (12 weeks or more) of high supplemental quercetin levels (1,000 mg daily or above).
Although the therapeutic activities of quercetin are well established,* it has poor water solubility, chemical instability, and low bioavailability.5 Quercetin requires zinc to activate its therapeutic effects on the body. So, it is not a coincidence that zinc, the second most abundant trace metal in the body, is also involved in sleep regulation. The current research data6 suggest that zinc consumed orally enhances the amount and quality of sleep in mice and humans.
You might consider taking a nutritional supplement that contains both quercetin and zinc to improve the body's absorption of quercetin. Quercetin binds to zinc and acts as a transporter, carrying zinc ions across the cell membrane to enhance the intracellular zinc concentration.*
Although quercetin is widely considered to be safe as a nutritional supplement, you should consult with your health-care provider before including a quercetin supplement in your diet. Insufficient research data exists on quercetin effects during pregnancy and breastfeeding. So, it is always recommended to seek medical advice before consuming a quercetin supplement with any prescription medicine.
An effective quercetin nutritional supplement offers enhanced bioavailability of the active ingredient for optimal therapeutic benefit.* QuerciSorb® Immophore SR — an innovative nutritional supplement developed by Tesseract Medical Research — contains bioactive, soluble, and absorbable quercetin, along with zinc, vitamin D, and vitamin C to support your overall health.* The revolutionary CyLoc® - DexKey® nutrient delivery technology ensures that quercetin is delivered one molecule at a time at the desired point in the intestinal tract and absorbed through the gut wall, along with other therapeutic ingredients. Developed for sustained release (SR), QuerciSorb® Immuphore SR makes it easy for the body to absorb and use quercetin effectively.
The power of Tesseract supplements lies in enhancing palatability, maximizing bioavailability and absorption, and micro-dosing multiple nutrients in a single, highly effective capsule. Shop products on our website and learn more about how they can help support cardiovascular health.*
1 Kanazawa, Luiz KS, et al. Free Radical Biology & Medicine vol. 99 (2016): 79-86. doi:10.1016/j.freeradbiomed.2016.07.027
3Deepika, Maurya PK. Molecules 2022 Apr 13;27(8):2498. doi: 10.3390/molecules27082498. PMID: 35458696; PMCID: PMC9032170.
4Andres, Susanne et al. Molecular Nutrition & Food Research vol. 62,1 (2018): 10.1002/mnfr.201700447. doi:10.1002/mnfr.201700447
5Acıkara OB, Karatoprak GŞ, et al. CNS Neurol Disord Drug Targets 2022;21(9):795-817. doi: 10.2174/1871527320666211206122407. PMID: 34872486.
6 Yoan C, Urade Y. International Journal of Molecular Sciences vol. 18,11 2334. 5 Nov. 2017, doi:10.3390/ijms18112334