Reviewed By
Overview
SCIENTIFIC SCORE
Moderately Effective
Based on 3 Researches
8.3
USERS' SCORE
Good
Based on 56 Reviews
8.1
Supplement Facts
Serving Size: 1 Capsule
Amount Per Serving
%DV
Quercetin
500 mg
†
Top Medical Research Studies
8
We observed that quercetin, a powerful antioxidant, plays a significant role in helping grapes withstand cold temperatures. In our study, we found that grapes exposed to low temperatures accumulate more quercetin, which in turn enhances their cold resistance.
By applying exogenous quercetin, we noted a marked improvement in the grapes' ability to endure low-temperature stress. Our research revealed that a key gene, VvFLS1, responsible for quercetin synthesis is upregulated when grapes experience cold conditions.
We also discovered that VvbZIP22, a protein that binds to the VvFLS1 promoter, is crucial for mediating this process. When we overexpressed VvbZIP22 in grapes, it resulted in higher levels of quercetin and improved cold resistance, further confirming its pivotal role in the plant's adaptation to harsh environments.
Through these findings, we highlighted the importance of quercetin in enhancing grape survival during cold spells, showcasing a vital link between plant biology and climate resilience.
By applying exogenous quercetin, we noted a marked improvement in the grapes' ability to endure low-temperature stress. Our research revealed that a key gene, VvFLS1, responsible for quercetin synthesis is upregulated when grapes experience cold conditions.
We also discovered that VvbZIP22, a protein that binds to the VvFLS1 promoter, is crucial for mediating this process. When we overexpressed VvbZIP22 in grapes, it resulted in higher levels of quercetin and improved cold resistance, further confirming its pivotal role in the plant's adaptation to harsh environments.
Through these findings, we highlighted the importance of quercetin in enhancing grape survival during cold spells, showcasing a vital link between plant biology and climate resilience.
Read More
8
Quercetin limits HRV1B replication
We investigated how quercetin-3-methyl ether, a natural flavonoid, impacts human rhinovirus 1B (HRV1B), which is responsible for the common cold and can worsen conditions like asthma. Our research involved testing this compound in HeLa cells to see if it could reduce viral replication and the damage associated with the virus.
In our experiments, quercetin-3-methyl ether significantly inhibited the replication of HRV1B in a concentration-dependent way, which means that higher doses produced better results. We also found that this compound enhanced early apoptosis—essentially, the process by which infected cells shut down in response to the virus—during the critical early stages of infection. This seemed to counteract HRV1B's tactics to evade the immune response.
Additionally, when we administered quercetin-3-methyl ether to mice infected with HRV1B, we observed a noteworthy reduction in viral RNA levels and inflammation in their lung tissues, suggesting a potential therapeutic effect. Our findings enhance the understanding of quercetin-3-methyl ether as a novel agent against HRV1B, pointing towards promising strategies for managing cold-related illnesses and their complications.
In our experiments, quercetin-3-methyl ether significantly inhibited the replication of HRV1B in a concentration-dependent way, which means that higher doses produced better results. We also found that this compound enhanced early apoptosis—essentially, the process by which infected cells shut down in response to the virus—during the critical early stages of infection. This seemed to counteract HRV1B's tactics to evade the immune response.
Additionally, when we administered quercetin-3-methyl ether to mice infected with HRV1B, we observed a noteworthy reduction in viral RNA levels and inflammation in their lung tissues, suggesting a potential therapeutic effect. Our findings enhance the understanding of quercetin-3-methyl ether as a novel agent against HRV1B, pointing towards promising strategies for managing cold-related illnesses and their complications.
Read More
9
We explored how the combination of quercetin (QE) and sucrose (Suc) improves the preservation of porcine liver grafts affected by warm ischemia followed by cold storage. Our study involved two groups of porcine livers: one preserved with the standard University of Wisconsin (UW) solution and the other with the UW solution enhanced with QE and Suc.
After preserving the livers for six hours, we subjected them to a simulated reperfusion model using saline-diluted autologous blood. To measure success, we looked at several indicators of liver health, including specific enzyme levels and histological changes.
The results were promising! The livers treated with QE and Suc showed significantly lower levels of enzymes indicating liver damage compared to those using just the UW solution. Additionally, the histological analysis revealed fewer signs of injury in the QE and Suc group, showcasing their potential in reducing cold injury in liver grafts after ischemia.
Overall, our findings indicate that adding quercetin and sucrose to the preservation solution can effectively protect liver grafts from damage caused by cold storage, especially in cases of donation after circulatory death.
After preserving the livers for six hours, we subjected them to a simulated reperfusion model using saline-diluted autologous blood. To measure success, we looked at several indicators of liver health, including specific enzyme levels and histological changes.
The results were promising! The livers treated with QE and Suc showed significantly lower levels of enzymes indicating liver damage compared to those using just the UW solution. Additionally, the histological analysis revealed fewer signs of injury in the QE and Suc group, showcasing their potential in reducing cold injury in liver grafts after ischemia.
Overall, our findings indicate that adding quercetin and sucrose to the preservation solution can effectively protect liver grafts from damage caused by cold storage, especially in cases of donation after circulatory death.
Read More
Most Useful Reviews
9
Breathing better.
20 people found this helpful
WHERE HAVE YOU BEEN ALL MY LIFE? I have suffered from perennial rhinitis for as long as I can remember. Always sniffling and feeling blocked, leading to trouble breathing during activities. After struggling with bronchitis from post-nasal drip, and having been advised by my ENT doctor about swollen turbinates, I began taking this product. I’ve only had it for three days, one pill in the morning, and my turbinates have returned to normal size. My breathing is now completely unobstructed. This product is wonderful and appears more effective than similar options!
Read More
9
Effective for illness
16 people found this helpful
Jarrow Formulas Quercetin was recommended by my doctor, and I've taken it for over four years. As someone with a weakened immune system, I rarely get ill anymore, which I attribute to quercetin. Previously, I frequently caught colds and suffered from secondary infections, but now, I hardly catch anything. I'll always continue to take quercetin.
Read More
9
Knocks out cold
5 people found this helpful
For best results, take this with vitamin C. I find that taking 1500mg at the onset of a cold knocks it out overnight, showcasing its effectiveness.
Read More
Medical Researches
SCIENTIFIC SCORE
Moderately Effective
Based on 3 Researches
8.3
- All Researches
9
We explored how the combination of quercetin (QE) and sucrose (Suc) improves the preservation of porcine liver grafts affected by warm ischemia followed by cold storage. Our study involved two groups of porcine livers: one preserved with the standard University of Wisconsin (UW) solution and the other with the UW solution enhanced with QE and Suc.
After preserving the livers for six hours, we subjected them to a simulated reperfusion model using saline-diluted autologous blood. To measure success, we looked at several indicators of liver health, including specific enzyme levels and histological changes.
The results were promising! The livers treated with QE and Suc showed significantly lower levels of enzymes indicating liver damage compared to those using just the UW solution. Additionally, the histological analysis revealed fewer signs of injury in the QE and Suc group, showcasing their potential in reducing cold injury in liver grafts after ischemia.
Overall, our findings indicate that adding quercetin and sucrose to the preservation solution can effectively protect liver grafts from damage caused by cold storage, especially in cases of donation after circulatory death.
After preserving the livers for six hours, we subjected them to a simulated reperfusion model using saline-diluted autologous blood. To measure success, we looked at several indicators of liver health, including specific enzyme levels and histological changes.
The results were promising! The livers treated with QE and Suc showed significantly lower levels of enzymes indicating liver damage compared to those using just the UW solution. Additionally, the histological analysis revealed fewer signs of injury in the QE and Suc group, showcasing their potential in reducing cold injury in liver grafts after ischemia.
Overall, our findings indicate that adding quercetin and sucrose to the preservation solution can effectively protect liver grafts from damage caused by cold storage, especially in cases of donation after circulatory death.
Read More
8
Quercetin limits HRV1B replication
We investigated how quercetin-3-methyl ether, a natural flavonoid, impacts human rhinovirus 1B (HRV1B), which is responsible for the common cold and can worsen conditions like asthma. Our research involved testing this compound in HeLa cells to see if it could reduce viral replication and the damage associated with the virus.
In our experiments, quercetin-3-methyl ether significantly inhibited the replication of HRV1B in a concentration-dependent way, which means that higher doses produced better results. We also found that this compound enhanced early apoptosis—essentially, the process by which infected cells shut down in response to the virus—during the critical early stages of infection. This seemed to counteract HRV1B's tactics to evade the immune response.
Additionally, when we administered quercetin-3-methyl ether to mice infected with HRV1B, we observed a noteworthy reduction in viral RNA levels and inflammation in their lung tissues, suggesting a potential therapeutic effect. Our findings enhance the understanding of quercetin-3-methyl ether as a novel agent against HRV1B, pointing towards promising strategies for managing cold-related illnesses and their complications.
In our experiments, quercetin-3-methyl ether significantly inhibited the replication of HRV1B in a concentration-dependent way, which means that higher doses produced better results. We also found that this compound enhanced early apoptosis—essentially, the process by which infected cells shut down in response to the virus—during the critical early stages of infection. This seemed to counteract HRV1B's tactics to evade the immune response.
Additionally, when we administered quercetin-3-methyl ether to mice infected with HRV1B, we observed a noteworthy reduction in viral RNA levels and inflammation in their lung tissues, suggesting a potential therapeutic effect. Our findings enhance the understanding of quercetin-3-methyl ether as a novel agent against HRV1B, pointing towards promising strategies for managing cold-related illnesses and their complications.
Read More
8
We observed that quercetin, a powerful antioxidant, plays a significant role in helping grapes withstand cold temperatures. In our study, we found that grapes exposed to low temperatures accumulate more quercetin, which in turn enhances their cold resistance.
By applying exogenous quercetin, we noted a marked improvement in the grapes' ability to endure low-temperature stress. Our research revealed that a key gene, VvFLS1, responsible for quercetin synthesis is upregulated when grapes experience cold conditions.
We also discovered that VvbZIP22, a protein that binds to the VvFLS1 promoter, is crucial for mediating this process. When we overexpressed VvbZIP22 in grapes, it resulted in higher levels of quercetin and improved cold resistance, further confirming its pivotal role in the plant's adaptation to harsh environments.
Through these findings, we highlighted the importance of quercetin in enhancing grape survival during cold spells, showcasing a vital link between plant biology and climate resilience.
By applying exogenous quercetin, we noted a marked improvement in the grapes' ability to endure low-temperature stress. Our research revealed that a key gene, VvFLS1, responsible for quercetin synthesis is upregulated when grapes experience cold conditions.
We also discovered that VvbZIP22, a protein that binds to the VvFLS1 promoter, is crucial for mediating this process. When we overexpressed VvbZIP22 in grapes, it resulted in higher levels of quercetin and improved cold resistance, further confirming its pivotal role in the plant's adaptation to harsh environments.
Through these findings, we highlighted the importance of quercetin in enhancing grape survival during cold spells, showcasing a vital link between plant biology and climate resilience.
Read More
User Reviews
USERS' SCORE
Good
Based on 56 Reviews
8.1
- All Reviews
- Positive Reviews
- Negative Reviews
9
Breathing better.
20 people found this helpful
WHERE HAVE YOU BEEN ALL MY LIFE? I have suffered from perennial rhinitis for as long as I can remember. Always sniffling and feeling blocked, leading to trouble breathing during activities. After struggling with bronchitis from post-nasal drip, and having been advised by my ENT doctor about swollen turbinates, I began taking this product. I’ve only had it for three days, one pill in the morning, and my turbinates have returned to normal size. My breathing is now completely unobstructed. This product is wonderful and appears more effective than similar options!
Read More
9
Effective for illness
16 people found this helpful
Jarrow Formulas Quercetin was recommended by my doctor, and I've taken it for over four years. As someone with a weakened immune system, I rarely get ill anymore, which I attribute to quercetin. Previously, I frequently caught colds and suffered from secondary infections, but now, I hardly catch anything. I'll always continue to take quercetin.
Read More
9
Knocks out cold
5 people found this helpful
For best results, take this with vitamin C. I find that taking 1500mg at the onset of a cold knocks it out overnight, showcasing its effectiveness.
Read More
9
Good for colds
3 people found this helpful
Excellent for colds.
Read More
7.5
Assists with colds
3 people found this helpful
Quercetin is an important natural antioxidant that supports the immune system. It acts as my first assistant for colds and various infections, allowing me to get through seasonal illnesses more easily and quickly.
Read More
Frequently Asked Questions
9
Knocks out cold
5 people found this helpful
For best results, take this with vitamin C. I find that taking 1500mg at the onset of a cold knocks it out overnight, showcasing its effectiveness.
7.5
Effective for recovery
1 people found this helpful
Useful when you start to catch a cold. I've been using this for three years. Whenever I catch a cold with a sore throat, I immediately take 1 pill in the morning and 1 in the evening. It helps me recover faster.
8
Effective for allergies
Excellent! A great remedy for allergies and colds. The key is to take it early at the first sign.
9
Effective for illness
16 people found this helpful
Jarrow Formulas Quercetin was recommended by my doctor, and I've taken it for over four years. As someone with a weakened immune system, I rarely get ill anymore, which I attribute to quercetin. Previously, I frequently caught colds and suffered from secondary infections, but now, I hardly catch anything. I'll always continue to take quercetin.
9
Cold-free for two years
Since taking one tablet (500 mg) daily for two years, my asthma and allergy symptoms have notably reduced. I haven’t had a cold during this time. It’s great value for such an effective supplement and easy to swallow. I take it each morning with a meal and zinc for optimal absorption.
7.5
Quick cold relief
14 people found this helpful
My alternative medicine doctor advised me to take Quercetin alongside my allergy medication. I usually take 4-8 capsules daily or take some before meals when unsure of the ingredients. It works wonders and minimises reactions. If I sense a cold coming on, I take extra with vitamin C; it effectively helps nip that cold in the bud.
8
Combat colds
The immune buster helped me tackle both Covid and cold seasons. It's excellent when combined with zinc for better absorption.
7.5
Recommended for colds
1 people found this helpful
Excellent! I learned about quercetin from a naturopath. It is taken at the onset of a cold. I took 1 tablet three times a day for the first three days, then 1 tablet once daily until recovery. I took it with my husband during a mild cold, and I didn't get sick as I normally would. I recommend purchasing it.
8
Quercetin limits HRV1B replication
We investigated how quercetin-3-methyl ether, a natural flavonoid, impacts human rhinovirus 1B (HRV1B), which is responsible for the common cold and can worsen conditions like asthma. Our research involved testing this compound in HeLa cells to see if it could reduce viral replication and the damage associated with the virus.
In our experiments, quercetin-3-methyl ether significantly inhibited the replication of HRV1B in a concentration-dependent way, which means that higher doses produced better results. We also found that this compound enhanced early apoptosis—essentially, the process by which infected cells shut down in response to the virus—during the critical early stages of infection. This seemed to counteract HRV1B's tactics to evade the immune response.
Additionally, when we administered quercetin-3-methyl ether to mice infected with HRV1B, we observed a noteworthy reduction in viral RNA levels and inflammation in their lung tissues, suggesting a potential therapeutic effect. Our findings enhance the understanding of quercetin-3-methyl ether as a novel agent against HRV1B, pointing towards promising strategies for managing cold-related illnesses and their complications.
In our experiments, quercetin-3-methyl ether significantly inhibited the replication of HRV1B in a concentration-dependent way, which means that higher doses produced better results. We also found that this compound enhanced early apoptosis—essentially, the process by which infected cells shut down in response to the virus—during the critical early stages of infection. This seemed to counteract HRV1B's tactics to evade the immune response.
Additionally, when we administered quercetin-3-methyl ether to mice infected with HRV1B, we observed a noteworthy reduction in viral RNA levels and inflammation in their lung tissues, suggesting a potential therapeutic effect. Our findings enhance the understanding of quercetin-3-methyl ether as a novel agent against HRV1B, pointing towards promising strategies for managing cold-related illnesses and their complications.
References
- Song JH, Mun SH, Mishra S, Kim SR, Yang H, et al. Quercetin-3-Methyl Ether Induces Early Apoptosis to Overcome HRV1B Immune Evasion, Suppress Viral Replication, and Mitigate Inflammatory Pathogenesis. Biomol Ther (Seoul). 2025;33:388. 10.4062/biomolther.2024.204
- Liu G, Zhang Z, Tian Y, Yang J, Xu X, et al. VvbZIP22 regulates quercetin synthesis to enhances cold resistance in grape. Plant Sci. 2025;350:112293. 10.1016/j.plantsci.2024.112293
- Otani M, Ishii D, Iwata H, Satake Y, Okada Y, et al. Preservation Efficacy of a Quercetin and Sucrose Solution for Warm Ischemically Damaged Porcine Liver Grafts. Transplant Proc. 2023;55:2212. 10.1016/j.transproceed.2023.07.031
