Can NOW Supplements Quercetin with Bromelain Help with Blood Clot?

Overview

SCIENTIFIC SCORE

Possibly Effective

Based on 16 Researches

7.9

USERS' SCORE

Questionable

Based on 22 Reviews

5.1

Supplement Facts

Serving Size: 2 Veg Capsules

Amount Per Serving

%DV

Quercetin

800 mg

Bromelain (2,400 GDU/g)

165 mg

Top Medical Research Studies

9.5

Quercitrin reduces platelet activation

Oh TW, Do HJ, Jeon JH, Kim K. Quercitrin inhibits platelet activation in arterial thrombosis. Phytomedicine. 2021;80:153363. doi:10.1016/j.phymed.2020.153363

We explored the effects of quercitrin on platelet activation to better understand its role in blood clotting. Through comprehensive experiments—like assessing platelet aggregation and thrombus formation—we observed that quercitrin significantly hinders platelet activation. This means it impairs platelet aggregation and granule secretion, which are crucial in forming blood clots.

Moreover, quercitrin showed promise in preventing arterial thrombus formation without extending bleeding time, hinting at its potential as a treatment for thrombotic diseases. Overall, our findings suggest that quercitrin could be beneficial in managing blood clot-related conditions.

Quercetin reduces platelet activation

Manikanta K, NaveenKumar SK, Hemshekhar M, Thushara RM, Mugesh G, et al. Quercetin inhibits platelet activation and ER-stress mediated autophagy in response to extracellular histone. Phytomedicine. 2025;138:156386. doi:10.1016/j.phymed.2025.156386

We investigated how quercetin, a natural compound, can guard against the harmful effects of extracellular histones on platelets. Our study involved evaluating the interaction between histones and platelets in animal and lab settings.

We discovered that quercetin effectively inhibits histone-induced platelet activation and damage. This protection suggests that quercetin could be a valuable treatment option for conditions where histone toxicity plays a role, potentially assisting in the management of critical illnesses.

SXS shows promise against blood stasis

Wei X, Gao M, Sheng N, Yao W, Bao B, et al. Mechanism investigation of Shi-Xiao-San in treating blood stasis syndrome based on network pharmacology, molecular docking and in vitro/vivo pharmacological validation. J Ethnopharmacol. 2023;301:115746. doi:10.1016/j.jep.2022.115746

We investigated how Shi-Xiao-San, a traditional Chinese herbal formula, affects blood stasis, which relates to conditions like thrombosis and coronary heart disease. Through advanced techniques, we identified over 45 compounds, such as quercetin, that may play crucial roles in reducing blood viscosity and improving vascular health. Our tests showed that Shi-Xiao-San works by influencing key pathways involved in blood flow and inflammation. While promising, further studies are necessary to fully understand its mechanisms and benefits for treating blood clotting disorders.

Most Useful Reviews

Blood pressure reduction

9 people found this helpful

After taking quercetin, my blood pressure finally dropped to 110/70, a level I've never achieved before. The warmth in my feet suggests improved blood circulation, leading to a lower reading.

Strong allergy relief

1 people found this helpful

Amazing and effective rescue for strong allergy rashes! My private had severe allergy rashes; neither Claritine nor Lorrine provided significant relief, affecting his sleep for days. This supplement brought relief by the second day, with rashes and blood clots on his skin completely disappearing by day three. Dosage was as recommended (2+2). A tremendous relief that allowed him to sleep, exercise, and enjoy tea and coffee again. Very mild, with no side effects on kidneys or anything else. Highly recommended!

Blood pressure stabilisation

1 people found this helpful

After suffering from Covid, I experienced significant issues with my blood vessels and blood pressure. My doctor recommended quercetin, instructing me to take it an hour before or two hours after meals. While it is a long-term commitment (2-4 months) and not inexpensive, my condition has stabilised, so I’m completely satisfied and will continue the course.

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Medical Researches

SCIENTIFIC SCORE

Possibly Effective

Based on 16 Researches

7.9

9.5

Quercitrin reduces platelet activation

Oh TW, Do HJ, Jeon JH, Kim K. Quercitrin inhibits platelet activation in arterial thrombosis. Phytomedicine. 2021;80:153363. doi:10.1016/j.phymed.2020.153363

Quercetin as anticoagulant examined

Gogoi D, Chattopadhyay P, Dolui SK, Khan MR, Mukherjee AK. Studies on in vivo antithrombotic activity of quercetin, a natural flavonoid isolated from a traditional medicinal plant, African eggplant (Solanum indicum). J Ethnopharmacol. 2024;335:118686. doi:10.1016/j.jep.2024.118686

We investigated the potential of quercetin, a compound from the African eggplant, to act as an anticoagulant. By using various methods including bioassay-guided fractionation, we studied its effects on blood clotting in mice. Our experiments revealed promising anticoagulant activities.

While quercetin shows effectiveness against clot formation, further research is needed to fully understand its mechanisms and therapeutic potential in treating cardiovascular diseases. Overall, this suggests quercetin may serve as a valuable herbal option for cardiovascular health.

Taxifolin inhibits NETosis, aids thrombo-inflammation

Rysenga CE, May-Zhang L, Zahavi M, Knight JS, Ali RA. Taxifolin inhibits NETosis through activation of Nrf2 and provides protective effects in models of lupus and antiphospholipid syndrome. Rheumatology (Oxford). 2024;63:2006. doi:10.1093/rheumatology/kead547

We investigated how taxifolin, a bioactive flavonoid, could impact diseases associated with blood clots like lupus and antiphospholipid syndrome (APS). Using in vitro assays and mouse models, we observed that taxifolin significantly inhibits the formation of neutrophil extracellular traps—an action known as NETosis—linked to inflammation and clotting. Notably, taxifolin reduced autoantibody formation and large-vein thrombosis in these models. This pioneering study suggests that taxifolin may offer protective benefits against thrombo-inflammatory conditions, making it an exciting area for further research.

Baiying Qingmai reduces thrombosis

Zou C, Liu L, Huang C, Hu S. Baiying qingmai formulation ameliorates thromboangiitis obliterans by inhibiting HMGB1/RAGE/NF-κB signaling pathways. Front Pharmacol. 2022;13:1018438. doi:10.3389/fphar.2022.1018438

We explored how Baiying Qingmai Formulation (BF) affects thromboangiitis obliterans (TAO) by analyzing its chemical makeup and how it interacts with various signaling pathways.

Our findings showed that BF significantly inhibits important proteins related to inflammation and blood clotting. It not only decreases harmful cytokines but also increases protective metabolites in the bloodstream.

Ultimately, we believe BF offers a promising path to alleviate symptoms of TAO by reducing blood clots and improving vascular health in affected individuals.

Quercetin aids hemorrhoid treatment

Gravina AG, Pellegrino R, Facchiano A, Palladino G, Loguercio C, et al. Evaluation of the Efficacy and Safety of a Compound of Micronized Flavonoids in Combination With Vitamin C and Extracts of , , and for the Reduction of Hemorrhoidal Symptoms in Patients With Grade II and III Hemorrhoidal Disease: A Retrospective Real-Life Study. Front Pharmacol. 2021;12:773320. doi:10.3389/fphar.2021.773320

We closely examined a retrospective study focused on how a blend of micronized flavonoids, including quercetin, can alleviate symptoms of grade II and III hemorrhoidal disease.

Patients taking this compound showed a notable 89.8% success rate in reducing hemorrhoid severity after just one week of treatment.

Improvements were seen across a range of symptoms with no reported side effects. Overall, this study suggests that quercetin, alongside other ingredients, may effectively help manage hemorrhoidal symptoms safely.

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User Reviews

USERS' SCORE

Questionable

Based on 22 Reviews

5.1

Blood pressure reduction

9 people found this helpful

After taking quercetin, my blood pressure finally dropped to 110/70, a level I've never achieved before. The warmth in my feet suggests improved blood circulation, leading to a lower reading.

Strong allergy relief

1 people found this helpful

Blood pressure stabilisation

1 people found this helpful

7.5

Post-Covid benefits

1 people found this helpful

I started taking Quercetin in my recovery regimen after Covid. The results are excellent; headaches have significantly reduced, and shortness of breath has ceased. Being a powerful antioxidant, it aids in thinning the blood, and I will continue its regular use.

Caution advised

170 people found this helpful

I found the daily recommended dose of 500 mg too high, as the two capsules contain 800 mg. For instance, my five-year-old experienced nosebleeds after taking just one. Quercetin reduces blood clotting, which can pose risks; hence, I recommend starting at 250 mg. I prefer quercetin from Natural Factors, having heard no serious health concerns about it. Wishing health to all!

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Frequently Asked Questions

Strong allergy relief

1 people found this helpful

Blood pressure stabilisation

1 people found this helpful

Blood pressure reduction

9 people found this helpful

After taking quercetin, my blood pressure finally dropped to 110/70, a level I've never achieved before. The warmth in my feet suggests improved blood circulation, leading to a lower reading.

Vascular improvement

4 people found this helpful

Taking quercetin seems to prevent the coronavirus from adhering to receptors. It may improve blood vessel health, and I’ve noticed a drop in my blood pressure since starting it.

Blood pressure issue

I am taking this to manage my blood pressure, but it doesn't seem to lower it effectively.

No significant change

I began taking this for my high blood pressure, but I've not noticed any substantial changes. However, it appears to be beneficial for my body.

Improved blood flow

35 people found this helpful

My blood pressure has dropped since taking it, and my blood vessels feel softer. I'm hopeful it might help with cerebral blood flow and counter dementia, which worries me more than Covid.

7.5

Post-Covid benefits

1 people found this helpful

7.5

Reduced inflammation

5 people found this helpful

I've taken quercetin since September 2020 for my varicose veins and overall health. After cycles of chemotherapy, it helped reduce inflammation and supported my blood vessels. I feel much better.

No noticeable effects

2 people found this helpful

After my recent illness, I felt no improvements; my blood remained thick, and I received no relief for my hay fever. I don’t understand the enthusiasm in other reviews regarding this product.

7.5

Zinc absorption

2 people found this helpful

I take quercetin with zinc to enhance absorption, especially when infected with Covid. It helped my partner regain taste and smell within days, and it’s beneficial for preventing blood clots.

Acne reduction

3 people found this helpful

This product has worked well, clearing up 80% of my acne over the month with the combination of this and Virastop. However, I noticed I bleed more easily while brushing my teeth, likely due to its blood-thinning properties, so I will reduce my intake from four a day to one.

Caution advised

170 people found this helpful

7.5

Nasal relief

5 people found this helpful

I take one capsule of quercetin each morning with vitamin C and Iron. It seems to enhance vitamin C absorption and has improved my nasal inflammation, although it's not a miracle cure on its own.

Quercetin reduces platelet activation

Zaragozá C, Monserrat J, Mantecón C, Villaescusa L, Álvarez-Mon MÁ, et al. Binding and antiplatelet activity of quercetin, rutin, diosmetin, and diosmin flavonoids. Biomed Pharmacother. 2021;141:111867. doi:10.1016/j.biopha.2021.111867

We investigated whether quercetin, along with other flavonoids, impacts platelet activity, which is crucial for blood clotting. Using blood samples from healthy volunteers, we looked at how these compounds influence the activation states of platelets through a specialized laboratory technique.

Our findings showed that quercetin and the other flavonoids demonstrated significant antiplatelet activity, effectively blocking a key receptor involved in platelet aggregation. This work helps shed light on how these natural compounds may play a role in preventing cardiovascular issues by reducing unwanted blood clot formation.

Quercetin aids platelet function

Gauer JS, Ajanel A, Kaselampao LM, Candir I, MacCannell ADV, et al. Plant-derived compounds normalize platelet bioenergetics and function in hyperglycemia. Res Pract Thromb Haemost. 2024;8:102548. doi:10.1016/j.rpth.2024.102548

We explored the effects of polyphenols, specifically quercetin, on the bioenergetics and function of platelets under conditions of normoglycemia and acute hyperglycemia. Our study evaluated how these compounds can impact platelet activity that typically increases due to high blood sugar levels.

We found that the use of polyphenols like quercetin helps lessen heightened platelet activity caused by hyperglycemia. This suggests that quercetin might play a role in reducing clot formation risk for patients with diabetes.

Overall, polyphenols have promising potential in thrombosis prevention, but further research is likely needed to fully understand their benefits.

Quercetin's uncertain effects on clotting

Manjunath SH, Thimmulappa RK. Antiviral, immunomodulatory, and anticoagulant effects of quercetin and its derivatives: Potential role in prevention and management of COVID-19. J Pharm Anal. 2022;12:29. doi:10.1016/j.jpha.2021.09.009

We explored the potential of quercetin as a treatment related to COVID-19, especially its role in managing blood clotting. The research highlights that quercetin can help reduce coagulation issues, particularly in patients suffering from COVID-19, by inhibiting certain proteins involved in clot formation. However, while quercetin shows promise in this area, the evidence does not firmly establish its effectiveness as a definitive treatment for blood clots in COVID-19 patients. Further investigation is necessary to clarify its benefits in clinical settings.

Quercetin as anticoagulant examined

References

Dai J, He W, Liu SA, Huang S, He X, et al. Rapid screening of the antithrombotic active components of Ledeb with thrombin binding affinity ultrafiltration mass spectroscopy. Anal Methods. 2025;17:2046. doi:10.1039/d4ay01909a
Manikanta K, NaveenKumar SK, Hemshekhar M, Thushara RM, Mugesh G, et al. Quercetin inhibits platelet activation and ER-stress mediated autophagy in response to extracellular histone. Phytomedicine. 2025;138:156386. doi:10.1016/j.phymed.2025.156386
Gauer JS, Ajanel A, Kaselampao LM, Candir I, MacCannell ADV, et al. Plant-derived compounds normalize platelet bioenergetics and function in hyperglycemia. Res Pract Thromb Haemost. 2024;8:102548. doi:10.1016/j.rpth.2024.102548
Gogoi D, Chattopadhyay P, Dolui SK, Khan MR, Mukherjee AK. Studies on in vivo antithrombotic activity of quercetin, a natural flavonoid isolated from a traditional medicinal plant, African eggplant (Solanum indicum). J Ethnopharmacol. 2024;335:118686. doi:10.1016/j.jep.2024.118686
Rysenga CE, May-Zhang L, Zahavi M, Knight JS, Ali RA. Taxifolin inhibits NETosis through activation of Nrf2 and provides protective effects in models of lupus and antiphospholipid syndrome. Rheumatology (Oxford). 2024;63:2006. doi:10.1093/rheumatology/kead547
Fan W, Lan S, Yang Y, Liang J. Network pharmacology prediction and molecular docking-based strategy to discover the potential pharmacological mechanism of Huang-Qi-Gui-Zhi-Wu-Wu decoction against deep vein thrombosis. J Orthop Surg Res. 2023;18:475. doi:10.1186/s13018-023-03948-6
Zou C, Liu L, Huang C, Hu S. Baiying qingmai formulation ameliorates thromboangiitis obliterans by inhibiting HMGB1/RAGE/NF-κB signaling pathways. Front Pharmacol. 2022;13:1018438. doi:10.3389/fphar.2022.1018438
Wei X, Gao M, Sheng N, Yao W, Bao B, et al. Mechanism investigation of Shi-Xiao-San in treating blood stasis syndrome based on network pharmacology, molecular docking and in vitro/vivo pharmacological validation. J Ethnopharmacol. 2023;301:115746. doi:10.1016/j.jep.2022.115746
Hu M, Peng X, Shi S, Wan C, Cheng C, et al. Sulfonated, oxidized pectin-based double crosslinked bioprosthetic valve leaflets for synergistically enhancing hemocompatibility and cytocompatibility and reducing calcification. J Mater Chem B. 2022;10:8218. doi:10.1039/d2tb01704k
Liao X, Zhuang X, Liang C, Li J, Flaumenhaft R, et al. Flavonoids as Protein Disulfide Isomerase Inhibitors: Key Molecular and Structural Features for the Interaction. J Agric Food Chem. 2022;70:4475. doi:10.1021/acs.jafc.1c07994
Gravina AG, Pellegrino R, Facchiano A, Palladino G, Loguercio C, et al. Evaluation of the Efficacy and Safety of a Compound of Micronized Flavonoids in Combination With Vitamin C and Extracts of , , and for the Reduction of Hemorrhoidal Symptoms in Patients With Grade II and III Hemorrhoidal Disease: A Retrospective Real-Life Study. Front Pharmacol. 2021;12:773320. doi:10.3389/fphar.2021.773320
Manjunath SH, Thimmulappa RK. Antiviral, immunomodulatory, and anticoagulant effects of quercetin and its derivatives: Potential role in prevention and management of COVID-19. J Pharm Anal. 2022;12:29. doi:10.1016/j.jpha.2021.09.009
Lee S, Yu Y, Trimpert J, Benthani F, Mairhofer M, et al. Virus-induced senescence is a driver and therapeutic target in COVID-19. Nature. 2021;599:283. doi:10.1038/s41586-021-03995-1
Zaragozá C, Monserrat J, Mantecón C, Villaescusa L, Álvarez-Mon MÁ, et al. Binding and antiplatelet activity of quercetin, rutin, diosmetin, and diosmin flavonoids. Biomed Pharmacother. 2021;141:111867. doi:10.1016/j.biopha.2021.111867
Rojas-Garbanzo C, Rodríguez L, Pérez AM, Mayorga-Gross AL, Vásquez-Chaves V, et al. Anti-platelet activity and chemical characterization by UPLC-DAD-ESI-QTOF-MS of the main polyphenols in extracts from Psidium leaves and fruits. Food Res Int. 2021;141:110070. doi:10.1016/j.foodres.2020.110070
Oh TW, Do HJ, Jeon JH, Kim K. Quercitrin inhibits platelet activation in arterial thrombosis. Phytomedicine. 2021;80:153363. doi:10.1016/j.phymed.2020.153363