Supplementing Quercetin for Neurotrophic and Senolytic Effects

Click here to watch the companion video to this blog post.

My favorite quercetin supplements:

  1. Thorne Research's Phytosomal Quercetin, which you can find here.

  2. Double Wood's very cheap product, which you can find here.

  3. BulkSupplements' product, which you can find here.

A comparison of these products' prices per mg of quercetin can be found at this end of this blog post.


1. Flavonoids are categorized into flavonols, flavones, flavanones, catechins, and anthocyanidins[1].

a. Flavonols include quercetin, fisetin, galangin, kaempferol, myricetin, quercitrin, and rutin.

2. Quercetin (3,3’,4’,5,7-pentahydroxylflavone) is the most prevalent flavonoid in food, followed by kaempferol[2].

3. Quercetin is found as quercetin aglycone in food and quercetin rutinoside (also called rutin) in tea, where aglycone is absorbed more quickly and uniformly by people[3].

4. The richest quercetin containing foods in descending order are elderberries, red onions, white onions, cranberries, green hot peppers, kale, blueberries, and red apples[4].


1. Quercetin’s various metabolites have differential ability to scavenge free radicals[5][6].

2. Using human leukemia cells stimulated by lipopolysaccharides, quercetin was shown to inhibit reactive oxygen and nitrogen species with a higher reduction potential than curcumin at three different PHs and a total antioxidant capacity (TAC) 3.5x more powerful than curcumin[7].

3. On the DPPH assay, quercetin’s ability to scavenge free radicals is worse than EGCG and tied with epicatechin gallate (ECG), though it is superior to myricetin and kaempferol[8].

4. Quercetin’s ORAC score is lower than kaempferol and myricetin (and all of the catechins, which are led by epicatechin)[9].

5. In the FRAP and ABTS assays, quercetin is a better free radical scavenger than alpha-tocopherol[10].

6. It is less effective than epigallocatechin gallate (EGCG) at inhibiting DNA damage but more capable at producing DNA damage (at high concentrations)[11].


1. Nanoparticles have been developed to deliver quercetin[12][13].

2. Quercetin reduced oxidative stress by inhibiting inducible nitric oxide synthase protein expression and mitochondrial superoxide radicals and reduced the expression of IL-6, IL-1beta, and TNF-alpha in microglia treated with the Parkinsonian toxin MPP[14].

3. In rodent models of cerebral ischemia (hypoxic brain), quercetin protects neurons from apoptosis likely via upregulated of TrkB and BDNF[15].

4. Higher doses of quercetin increase BDNF mRNA in the rodent hippocampus[16].

5. In a model of polychlorinated biphenyl (PCBs) toxicity, PCB-induced suppression of rodent steroidogenesis was attenuated by quercetin. Quercetin also attenuated reductions on estrogen receptors in the hippocampus and BDNF signaling[17].

6. In a model of dimethylhydrazine-induced colorectal cancer, quercetin (with exercise) reduced tumor incidence, improved depressive symptoms, and upregulated BDNF[18].

7. In a model of lipopolysaccharide-induced rodent depression (and anxiety[19]), quercetin could attenuated LPS-induced downregulation of BDNF[20].

8. In a rodent model of oxidative injury to a mother, quercetin given to the mother improved BDNF signaling in offspring[21].

9. In rodents, quercetin can prophylactically protect rodents from memory impairments due to hypoxia[22].

10. In a rodent model of transgenic Parkinsonian mice, it appears that quercetin attenuates the progression of the disease[23].

11. Pre-treatment with quercetin limits dopaminergic neuron loss from the MPP toxin[24].

12. Quercetin improved BDNF expression after a spinal chord injury to rodents[25].

13. In a transgenic rodent model of Alzheimer’s, quercetin was more effective at attenuating the pathology of beta amyloid plaques when the rodents were given less vitamin D[26].

14. Quercetin’s neuroprotective element may require greater concentrations of the flavonoid than myricetin[27].

15. Chronic unpredicted stress (CUS) produces cognitive dysfunction and insulin resistance in rodents. Quercetin upregulates GLUT4 expression in the hippocampus and alleviates memory dysfunction[28].

16. Quercetin protects against dopaminergic dysfunction due to cadmium toxicity in a rodent model[29].

17. Quercetin and its glucosides (including rutin) affect alpha7 nicotinic cholinergic receptor ion currents. Quercetin increases them and rutin most potently decreases them[30].

18. Quercetin can attenuate GABA-A alpha5 receptor downregulation due to glutamate excitotoxicity (as seen here in a mouse seizure model with kainic acid[31]).


1. Quercetin is selectively cytotoxic against cancers cells of blood, brain, lung, uterine, skin, and salivary glands[32].

a. It is compared to other flavonoids in this paper[33].

2. Quercetin aglycone interacts with the aryl hydrocarbon receptor and modulates MEK/ERK and Nrf2/keap1 pathways[34].

3. Quercetin is also thought to reduce the phosphorylation of activated heat shock protein transcription factor (HSF)[35], allowing it to experience proteolytic degradation, thereby reducing heat shock protein expression[36]. Heat shock proteins are overexpressed in tumors[37].

4. Quercetin inhibits breast cancer stem cell development[38].

5. Quercetin’s cytotoxicity to human prostate and skin cancer cell lines is enhanced with ultrasound use[39].

6. Quercetin sensitizes prostate cancer cells to chemotherapeutic medicines, such as docetaxel[40].

7. Quercetin improves apoptosis in human pancreatic cancer cell lines[41].

8. Quercetin suppresses the development of metastatic osteosarcoma cancer cells[42].

9. Quercetin nanoparticles exert an anti-tumor effect on hepatocellular carcinoma cells by inhibiting NFkB, COX-2, and Akt signalling[43].

a. Quercetin is also being investigated as a treatment for primary liver tumors (PLTs), due to its competitive inhibition of the glucose transporter 1 (GLUT1), which is upregulated in PLT[44].


1. Quercetin upregulates the expression of metallothioneins, which in turn may phosphorylate JNK, p38, and PI3K/Akt, and may enhance Nrf2 activity. This produces a protective effect over hepatocytes[45].

2. In a rodent model of T2D-induced NAFLD, quercetin improved inflammatory measures, bile acid measures, and reduced fat retention in the liver[46].

3. Quercetin has imp