Overview
SCIENTIFIC SCORE
Moderately Effective
Based on 5 Researches
8.2
USERS' SCORE
Moderately Good
Based on 48 Reviews
7.8
Supplement Facts
Serving Size: 2 VegCaps
Amount Per Serving
%DV
Vitamin C (as Ascorbic Acid)
1,235 mg
1,372%
Quercetin
465 mg
*
Bromelain (Supplying 90 MCU)
50 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
7
Effectiveness of Vitamin C on Colds
We explored the effects of vitamin C on the common cold and pneumonia by examining a range of studies. Interestingly, research on animals suggests that vitamin C may have protective effects against infections. However, when it comes to preventing colds in the general population, taking more than 1 gram of vitamin C per day didn’t show significant benefits.
But there's a twist! Participants engaged in heavy physical activities saw their cold incidence reduced by half with vitamin C supplementation. Additionally, regular intake of 1 gram or more daily was linked to a 15% decrease in cold severity. While some therapeutic trials showed inconsistent results when vitamin C was taken after cold symptoms appeared, two studies did indicate that larger doses (6-8 grams per day) could effectively shorten the duration of colds compared to lower doses.
Our investigation also looked into pneumonia, but the studies were conducted in unique settings, such as a boarding school and military recruits. This makes it hard to generalize the findings to the wider population. Yet, some trials suggested benefits for pneumonia patients. Finally, the role of vitamin C in treating COVID-19 and sepsis remains unclear, with mixed results.
Given that vitamin C seems to alleviate symptoms and shorten the duration of colds, while being safe and affordable, it might be worth considering a dose of 6-8 grams per day to see if it helps at an individual level.
But there's a twist! Participants engaged in heavy physical activities saw their cold incidence reduced by half with vitamin C supplementation. Additionally, regular intake of 1 gram or more daily was linked to a 15% decrease in cold severity. While some therapeutic trials showed inconsistent results when vitamin C was taken after cold symptoms appeared, two studies did indicate that larger doses (6-8 grams per day) could effectively shorten the duration of colds compared to lower doses.
Our investigation also looked into pneumonia, but the studies were conducted in unique settings, such as a boarding school and military recruits. This makes it hard to generalize the findings to the wider population. Yet, some trials suggested benefits for pneumonia patients. Finally, the role of vitamin C in treating COVID-19 and sepsis remains unclear, with mixed results.
Given that vitamin C seems to alleviate symptoms and shorten the duration of colds, while being safe and affordable, it might be worth considering a dose of 6-8 grams per day to see if it helps at an individual level.
Read More
9
We explored the effects of ascorbic acid, commonly known as vitamin C, on cold tolerance in tomato seedlings. In our study, we discovered that applying vitamin C significantly boosts the seedlings' ability to handle cold stress.
By enhancing the antioxidant defense system, vitamin C treatment increased the enzyme activity in the seedlings' leaves. Additionally, it raised levels of important compounds such as proline, sugar, and abscisic acid, all of which play crucial roles in plant stress responses.
Our observations showed that vitamin C also protects the photosynthesis system of tomato seedlings. This implies that it helps maintain chlorophyll function, which is critical for the plant's overall health, especially under cold conditions.
Moreover, we found that vitamin C treatments led to increased expression of genes linked to antioxidant enzymes and cold response mechanisms. Overall, our findings suggest that exogenous vitamin C is a beneficial approach to improve cold tolerance in tomatoes and may provide helpful insights for farmers looking to cultivate hardier varieties during colder months.
By enhancing the antioxidant defense system, vitamin C treatment increased the enzyme activity in the seedlings' leaves. Additionally, it raised levels of important compounds such as proline, sugar, and abscisic acid, all of which play crucial roles in plant stress responses.
Our observations showed that vitamin C also protects the photosynthesis system of tomato seedlings. This implies that it helps maintain chlorophyll function, which is critical for the plant's overall health, especially under cold conditions.
Moreover, we found that vitamin C treatments led to increased expression of genes linked to antioxidant enzymes and cold response mechanisms. Overall, our findings suggest that exogenous vitamin C is a beneficial approach to improve cold tolerance in tomatoes and may provide helpful insights for farmers looking to cultivate hardier varieties during colder months.
Read More
Most Useful Reviews
9
Prevent colds
1 people found this helpful
It is an excellent ingredient for preventing colds during seasonal changes. I give it to my children every two days when they return to school. Thanks to this, I remain healthy and do not catch a cold. I also believe it helps alleviate rhinitis.
Read More
9
Reduced allergies
1 people found this helpful
This product effectively manages nose allergies. I've repurchased it numerous times, and I've noticed that my children's allergies have improved significantly, leading to fewer colds and better sleep during the night.
Read More
9
Reduces cold symptoms
1 people found this helpful
Cuts the duration and symptoms of a cold! If taken at the first sign of a cold, it may even alleviate it or lessen the intensity.
Read More
Medical Researches
SCIENTIFIC SCORE
Moderately Effective
Based on 5 Researches
8.2
- 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
9
We explored the effects of ascorbic acid, commonly known as vitamin C, on cold tolerance in tomato seedlings. In our study, we discovered that applying vitamin C significantly boosts the seedlings' ability to handle cold stress.
By enhancing the antioxidant defense system, vitamin C treatment increased the enzyme activity in the seedlings' leaves. Additionally, it raised levels of important compounds such as proline, sugar, and abscisic acid, all of which play crucial roles in plant stress responses.
Our observations showed that vitamin C also protects the photosynthesis system of tomato seedlings. This implies that it helps maintain chlorophyll function, which is critical for the plant's overall health, especially under cold conditions.
Moreover, we found that vitamin C treatments led to increased expression of genes linked to antioxidant enzymes and cold response mechanisms. Overall, our findings suggest that exogenous vitamin C is a beneficial approach to improve cold tolerance in tomatoes and may provide helpful insights for farmers looking to cultivate hardier varieties during colder months.
By enhancing the antioxidant defense system, vitamin C treatment increased the enzyme activity in the seedlings' leaves. Additionally, it raised levels of important compounds such as proline, sugar, and abscisic acid, all of which play crucial roles in plant stress responses.
Our observations showed that vitamin C also protects the photosynthesis system of tomato seedlings. This implies that it helps maintain chlorophyll function, which is critical for the plant's overall health, especially under cold conditions.
Moreover, we found that vitamin C treatments led to increased expression of genes linked to antioxidant enzymes and cold response mechanisms. Overall, our findings suggest that exogenous vitamin C is a beneficial approach to improve cold tolerance in tomatoes and may provide helpful insights for farmers looking to cultivate hardier varieties during colder months.
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
7
Effectiveness of Vitamin C on Colds
We explored the effects of vitamin C on the common cold and pneumonia by examining a range of studies. Interestingly, research on animals suggests that vitamin C may have protective effects against infections. However, when it comes to preventing colds in the general population, taking more than 1 gram of vitamin C per day didn’t show significant benefits.
But there's a twist! Participants engaged in heavy physical activities saw their cold incidence reduced by half with vitamin C supplementation. Additionally, regular intake of 1 gram or more daily was linked to a 15% decrease in cold severity. While some therapeutic trials showed inconsistent results when vitamin C was taken after cold symptoms appeared, two studies did indicate that larger doses (6-8 grams per day) could effectively shorten the duration of colds compared to lower doses.
Our investigation also looked into pneumonia, but the studies were conducted in unique settings, such as a boarding school and military recruits. This makes it hard to generalize the findings to the wider population. Yet, some trials suggested benefits for pneumonia patients. Finally, the role of vitamin C in treating COVID-19 and sepsis remains unclear, with mixed results.
Given that vitamin C seems to alleviate symptoms and shorten the duration of colds, while being safe and affordable, it might be worth considering a dose of 6-8 grams per day to see if it helps at an individual level.
But there's a twist! Participants engaged in heavy physical activities saw their cold incidence reduced by half with vitamin C supplementation. Additionally, regular intake of 1 gram or more daily was linked to a 15% decrease in cold severity. While some therapeutic trials showed inconsistent results when vitamin C was taken after cold symptoms appeared, two studies did indicate that larger doses (6-8 grams per day) could effectively shorten the duration of colds compared to lower doses.
Our investigation also looked into pneumonia, but the studies were conducted in unique settings, such as a boarding school and military recruits. This makes it hard to generalize the findings to the wider population. Yet, some trials suggested benefits for pneumonia patients. Finally, the role of vitamin C in treating COVID-19 and sepsis remains unclear, with mixed results.
Given that vitamin C seems to alleviate symptoms and shorten the duration of colds, while being safe and affordable, it might be worth considering a dose of 6-8 grams per day to see if it helps at an individual level.
Read More
User Reviews
USERS' SCORE
Moderately Good
Based on 48 Reviews
7.8
- All Reviews
- Positive Reviews
- Negative Reviews
9
Prevent colds
1 people found this helpful
It is an excellent ingredient for preventing colds during seasonal changes. I give it to my children every two days when they return to school. Thanks to this, I remain healthy and do not catch a cold. I also believe it helps alleviate rhinitis.
Read More
9
Reduced allergies
1 people found this helpful
This product effectively manages nose allergies. I've repurchased it numerous times, and I've noticed that my children's allergies have improved significantly, leading to fewer colds and better sleep during the night.
Read More
9
Reduces cold symptoms
1 people found this helpful
Cuts the duration and symptoms of a cold! If taken at the first sign of a cold, it may even alleviate it or lessen the intensity.
Read More
9
Quick relief
An effective remedy! I took it for a cold and noticed significant improvement within three days.
Read More
9
Fast recovery
I take this supplement at the first signs of a cold, and I feel it goes away much faster. The quality is good, and the capsule size is satisfactory.
Read More
Frequently Asked Questions
9
Quick relief
An effective remedy! I took it for a cold and noticed significant improvement within three days.
9
Fast recovery
I take this supplement at the first signs of a cold, and I feel it goes away much faster. The quality is good, and the capsule size is satisfactory.
9
Excellent remedy
An excellent remedy for the onset of a cold.
7.5
Cold symptoms relief
Solaray® QBC Plex ™ is a robust blend of Quercetin, Bromelain, and Vitamin C. Quercetin supports respiratory and immune health. We take it at the initial signs of seasonal allergies or as we start catching colds, and it helps symptoms pass quickly. We consume it between meals.
9
Reduced allergies
1 people found this helpful
This product effectively manages nose allergies. I've repurchased it numerous times, and I've noticed that my children's allergies have improved significantly, leading to fewer colds and better sleep during the night.
9
Prevent colds
1 people found this helpful
It is an excellent ingredient for preventing colds during seasonal changes. I give it to my children every two days when they return to school. Thanks to this, I remain healthy and do not catch a cold. I also believe it helps alleviate rhinitis.
7.5
Easier recovery
Very helpful! It assisted me in recovering from coronavirus, and I have found that colds are more easily tolerated now.
7.5
Effective against viruses
3 people found this helpful
We use this supplement at the first sign of a cold or suspected virus. It combines several effective ingredients against ARVI. Adding zinc enhances its effectiveness even further.
9
Quick recovery
A great product; in the case of colds, alongside zinc and vitamin D, I recover very quickly.
7.5
Effective for infections
Quercetin is highly effective, especially for cold-related respiratory infections. Zinc can inhibit viral replication, and the natural extracts of quercetin from onions and apples, alongside pineapple enzymes, help reduce inflammation. Additionally, Vitamin C combats inflammation, showcasing impressive benefits with high bioavailability.
9
Effective for colds
Excellent super dosage for colds! At the first symptoms, I begin to take it.
7.5
Prevents sickness
It helps to prevent illness; we take it at the first signs of a cold.
7.5
Very effective complex
5 people found this helpful
Solaray® QBC Plex ™ comprises 250 mg quercetin, 625 mg vitamin C, and 25 mg bromelain per capsule. Quercetin, a natural flavonoid, boasts strong antioxidant properties. I purchased it to treat colds and COVID in the fall-winter season, alongside olive leaf extract. Studies suggest it's beneficial for reducing atherosclerosis risk, preventing cardiovascular issues, and lowering blood pressure. Quercetin also offers anti-inflammatory and anti-carcinogenic properties. Bromelain aids protein digestion, while vitamin C supports collagen synthesis and immune function. This complex truly seems effective for managing cold symptoms.
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.
7
Effectiveness of Vitamin C on Colds
We explored the effects of vitamin C on the common cold and pneumonia by examining a range of studies. Interestingly, research on animals suggests that vitamin C may have protective effects against infections. However, when it comes to preventing colds in the general population, taking more than 1 gram of vitamin C per day didn’t show significant benefits.
But there's a twist! Participants engaged in heavy physical activities saw their cold incidence reduced by half with vitamin C supplementation. Additionally, regular intake of 1 gram or more daily was linked to a 15% decrease in cold severity. While some therapeutic trials showed inconsistent results when vitamin C was taken after cold symptoms appeared, two studies did indicate that larger doses (6-8 grams per day) could effectively shorten the duration of colds compared to lower doses.
Our investigation also looked into pneumonia, but the studies were conducted in unique settings, such as a boarding school and military recruits. This makes it hard to generalize the findings to the wider population. Yet, some trials suggested benefits for pneumonia patients. Finally, the role of vitamin C in treating COVID-19 and sepsis remains unclear, with mixed results.
Given that vitamin C seems to alleviate symptoms and shorten the duration of colds, while being safe and affordable, it might be worth considering a dose of 6-8 grams per day to see if it helps at an individual level.
But there's a twist! Participants engaged in heavy physical activities saw their cold incidence reduced by half with vitamin C supplementation. Additionally, regular intake of 1 gram or more daily was linked to a 15% decrease in cold severity. While some therapeutic trials showed inconsistent results when vitamin C was taken after cold symptoms appeared, two studies did indicate that larger doses (6-8 grams per day) could effectively shorten the duration of colds compared to lower doses.
Our investigation also looked into pneumonia, but the studies were conducted in unique settings, such as a boarding school and military recruits. This makes it hard to generalize the findings to the wider population. Yet, some trials suggested benefits for pneumonia patients. Finally, the role of vitamin C in treating COVID-19 and sepsis remains unclear, with mixed results.
Given that vitamin C seems to alleviate symptoms and shorten the duration of colds, while being safe and affordable, it might be worth considering a dose of 6-8 grams per day to see if it helps at an individual level.
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. doi: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. doi: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. doi:10.1016/j.transproceed.2023.07.031
- Hemilä H, Chalker E. Vitamin C for the common cold and pneumonia. Pol Arch Intern Med. 2025;135. doi:10.20452/pamw.16926
- Wang X, Ran C, Fu Y, Han L, Yang X, et al. Application of Exogenous Ascorbic Acid Enhances Cold Tolerance in Tomato Seedlings through Molecular and Physiological Responses. Int J Mol Sci. 2024;25. doi:10.3390/ijms251810093
