Overview
SCIENTIFIC SCORE
Possibly Effective
Based on 7 Researches
7.6
USERS' SCORE
Moderately Good
Based on 112 Reviews
7.9
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
We investigated whether quercetin, a natural plant compound, could help combat common cold caused by rhinovirus (RV). In our study, quercetin reduced RV replication and inflammation in airway cells both in laboratory settings and in mice. When given before or after infection, quercetin limited the virus's ability to replicate and decreased harmful immune responses.
While our findings are promising, indicating that quercetin acts at various points in the virus's lifecycle, we recognize the need for further research to solidify its effectiveness in treating or preventing common colds.
While our findings are promising, indicating that quercetin acts at various points in the virus's lifecycle, we recognize the need for further research to solidify its effectiveness in treating or preventing common colds.
Read More
8
We investigated how quercetin 7-glucoside (Q7G), sourced from Lagerstroemia speciosa, affects human rhinovirus 2 (HRV2), a leading cause of the common cold. Utilizing a method to reduce cytopathic effects, we found that Q7G significantly reduced HRV2 replication by blocking the virus's early infection stage.
Interestingly, compared to ribavirin, a known antiviral, Q7G showed stronger efficacy, suggesting its potential as a treatment for HRV2. While these results are promising, further research is needed to assess the practicality of using Q7G in common cold therapies.
Interestingly, compared to ribavirin, a known antiviral, Q7G showed stronger efficacy, suggesting its potential as a treatment for HRV2. While these results are promising, further research is needed to assess the practicality of using Q7G in common cold therapies.
Read More
8
Quercetin's antiviral potential confirmed
We explored the effects of quercetin-3-methyl ether, a natural flavonoid, on the common cold virus, specifically human rhinovirus 1B (HRV1B).
In our study, we found that this compound not only inhibited the virus's replication in human cells but also targeted the early stages of infection.
Additionally, quercetin enhanced early cell death to help combat the virus's immune evasion tactics.
While our findings highlight its potential as a new antiviral agent, further research is necessary to confirm its effectiveness in broader treatments.
In our study, we found that this compound not only inhibited the virus's replication in human cells but also targeted the early stages of infection.
Additionally, quercetin enhanced early cell death to help combat the virus's immune evasion tactics.
While our findings highlight its potential as a new antiviral agent, further research is necessary to confirm its effectiveness in broader treatments.
Read More
Most Useful Reviews
9
Supports immune health
345 people found this helpful
Quercetin with bromelain works well for colds and prevents illness. I find it beneficial for immune system health. It aids the respiratory system and helps maintain good health all year round.
Read More
9
Alleviates symptoms
122 people found this helpful
I used quercetin for immune support, and it notably reduced pain in my mother's legs. Bromelain helps with allergies, and I've noticed improvements, including better sleep and reduced sweating during colds.
Read More
9
Effective for asthma
52 people found this helpful
Quercetin plus bromelain is particularly effective for allergy symptoms and bronchial asthma. This combination works well, clearing sinuses and enhancing overall immune strength during common colds.
Read More
Medical Researches
SCIENTIFIC SCORE
Possibly Effective
Based on 7 Researches
7.6
- All Researches
9
We explored the role of flavonoid compounds, like quercetin, in reducing the frequency and severity of upper respiratory tract infections (URTIs) in healthy adults. An in-depth review of 14 studies showed that flavonoid supplementation notably reduced the incidence of URTIs by 33% and sick days by 40%.
However, we noted that changes in immune markers were minimal, indicating that while there are advantages in reducing infections, the immune response may not be significantly affected.
However, we noted that changes in immune markers were minimal, indicating that while there are advantages in reducing infections, the immune response may not be significantly affected.
Read More
9
We investigated whether quercetin, a natural plant compound, could help combat common cold caused by rhinovirus (RV). In our study, quercetin reduced RV replication and inflammation in airway cells both in laboratory settings and in mice. When given before or after infection, quercetin limited the virus's ability to replicate and decreased harmful immune responses.
While our findings are promising, indicating that quercetin acts at various points in the virus's lifecycle, we recognize the need for further research to solidify its effectiveness in treating or preventing common colds.
While our findings are promising, indicating that quercetin acts at various points in the virus's lifecycle, we recognize the need for further research to solidify its effectiveness in treating or preventing common colds.
Read More
8
Quercetin's antiviral potential confirmed
We explored the effects of quercetin-3-methyl ether, a natural flavonoid, on the common cold virus, specifically human rhinovirus 1B (HRV1B).
In our study, we found that this compound not only inhibited the virus's replication in human cells but also targeted the early stages of infection.
Additionally, quercetin enhanced early cell death to help combat the virus's immune evasion tactics.
While our findings highlight its potential as a new antiviral agent, further research is necessary to confirm its effectiveness in broader treatments.
In our study, we found that this compound not only inhibited the virus's replication in human cells but also targeted the early stages of infection.
Additionally, quercetin enhanced early cell death to help combat the virus's immune evasion tactics.
While our findings highlight its potential as a new antiviral agent, further research is necessary to confirm its effectiveness in broader treatments.
Read More
8
Quercetin shows promise against viruses
We explored the effectiveness of quercetin-type flavonols in combating viral lower respiratory infections through a systematic review of 11 preclinical studies.
Our findings highlighted quercetin's impressive antiviral activity, showing lower mortality rates and reduced viral loads in infected animals.
Moreover, quercetin appeared to alleviate inflammation and mucus production, suggesting a multifaceted benefit for respiratory health. Overall, quercetin could be a promising option for those facing respiratory viral challenges.
Our findings highlighted quercetin's impressive antiviral activity, showing lower mortality rates and reduced viral loads in infected animals.
Moreover, quercetin appeared to alleviate inflammation and mucus production, suggesting a multifaceted benefit for respiratory health. Overall, quercetin could be a promising option for those facing respiratory viral challenges.
Read More
8
We investigated how quercetin 7-glucoside (Q7G), sourced from Lagerstroemia speciosa, affects human rhinovirus 2 (HRV2), a leading cause of the common cold. Utilizing a method to reduce cytopathic effects, we found that Q7G significantly reduced HRV2 replication by blocking the virus's early infection stage.
Interestingly, compared to ribavirin, a known antiviral, Q7G showed stronger efficacy, suggesting its potential as a treatment for HRV2. While these results are promising, further research is needed to assess the practicality of using Q7G in common cold therapies.
Interestingly, compared to ribavirin, a known antiviral, Q7G showed stronger efficacy, suggesting its potential as a treatment for HRV2. While these results are promising, further research is needed to assess the practicality of using Q7G in common cold therapies.
Read More
User Reviews
USERS' SCORE
Moderately Good
Based on 112 Reviews
7.9
- All Reviews
- Positive Reviews
- Negative Reviews
9
Supports immune health
345 people found this helpful
Quercetin with bromelain works well for colds and prevents illness. I find it beneficial for immune system health. It aids the respiratory system and helps maintain good health all year round.
Read More
9
Alleviates symptoms
122 people found this helpful
I used quercetin for immune support, and it notably reduced pain in my mother's legs. Bromelain helps with allergies, and I've noticed improvements, including better sleep and reduced sweating during colds.
Read More
9
Effective for asthma
52 people found this helpful
Quercetin plus bromelain is particularly effective for allergy symptoms and bronchial asthma. This combination works well, clearing sinuses and enhancing overall immune strength during common colds.
Read More
9
Allergy aid
16 people found this helpful
The combination of Quercetin and Bromelain is incredibly effective for allergies. Quercetin notably reduces allergy symptoms, including those from bronchial asthma. The anti-inflammatory effects of Bromelain enhance its efficacy, promoting sinus health and boosting the immune system.
Read More
10
Improves overall health
14 people found this helpful
I learned about this supplement from a doctor. Quercetin and bromelain improved my health during the common cold season, supporting my immune system and aiding digestion effectively.
Read More
Frequently Asked Questions
9
Stops symptoms quickly
2 people found this helpful
At the first signs of a common cold, I take a capsule in both the morning and evening. It effectively prevents illness and alleviates symptoms. Recently, when my friend's son was ill and had breathing issues, Quercetin helped resolve them in just two days.
9
Cold recovery
4 people found this helpful
Quercetin has been a lifesaver for me; after taking two capsules within three days of a common cold, my symptoms vanished. Initially sceptical, I am now convinced of its effectiveness.
9
Quick recovery
3 people found this helpful
Essential for combating the common cold! My weak immunity means that I catch colds easily, especially in harsh winter temperatures. Taking 3 capsules at the onset of illness helps me recover quickly, often within days.
9
Winter immunity boost
2 people found this helpful
Quercetin has been a huge help during dry winter months when I typically get a runny nose and cough. This time, I avoided those issues and noticed a significant boost in my immunity.
7.5
Mild improvements
2 people found this helpful
I bought this to help with my stuffy nose, encouraged by positive reviews. It seems to work a bit, reducing my chances of catching a common cold during seasonal changes. I look forward to trying it for pollen season.
9
Alleviates symptoms
122 people found this helpful
I used quercetin for immune support, and it notably reduced pain in my mother's legs. Bromelain helps with allergies, and I've noticed improvements, including better sleep and reduced sweating during colds.
9
Prevents common cold
6 people found this helpful
Quercetin is a powerful anti-COVID supplement for me. I take it alongside Vitamin D3, Vitamin C, and zinc to avoid even the common cold. The NOW family of products is my absolute favourite, relying on their quality since 1968.
9
Allergy aid
16 people found this helpful
The combination of Quercetin and Bromelain is incredibly effective for allergies. Quercetin notably reduces allergy symptoms, including those from bronchial asthma. The anti-inflammatory effects of Bromelain enhance its efficacy, promoting sinus health and boosting the immune system.
9
Supports immune health
345 people found this helpful
Quercetin with bromelain works well for colds and prevents illness. I find it beneficial for immune system health. It aids the respiratory system and helps maintain good health all year round.
10
Significant allergy relief
7 people found this helpful
This product is excellent for allergy relief! I suffered from cold-induced allergies, but after taking Quercetin and Bromelain, I noticed a significant difference. Initially, I took two capsules twice daily, and now I manage well with one capsule from November to April, effectively controlling my symptoms.
9
Effective relief
5 people found this helpful
I began taking these vitamins during the pandemic, and they have been invaluable for my chronic sinusitis. Over ten years of struggling with it, I have never experienced such improvement. I take one in the morning before meals, especially during exacerbations of the common cold or sinusitis. I am thoroughly impressed with the results and consistently purchase this brand now.
8
We investigated how quercetin 7-glucoside (Q7G), sourced from Lagerstroemia speciosa, affects human rhinovirus 2 (HRV2), a leading cause of the common cold. Utilizing a method to reduce cytopathic effects, we found that Q7G significantly reduced HRV2 replication by blocking the virus's early infection stage.
Interestingly, compared to ribavirin, a known antiviral, Q7G showed stronger efficacy, suggesting its potential as a treatment for HRV2. While these results are promising, further research is needed to assess the practicality of using Q7G in common cold therapies.
Interestingly, compared to ribavirin, a known antiviral, Q7G showed stronger efficacy, suggesting its potential as a treatment for HRV2. While these results are promising, further research is needed to assess the practicality of using Q7G in common cold therapies.
9
We investigated whether quercetin, a natural plant compound, could help combat common cold caused by rhinovirus (RV). In our study, quercetin reduced RV replication and inflammation in airway cells both in laboratory settings and in mice. When given before or after infection, quercetin limited the virus's ability to replicate and decreased harmful immune responses.
While our findings are promising, indicating that quercetin acts at various points in the virus's lifecycle, we recognize the need for further research to solidify its effectiveness in treating or preventing common colds.
While our findings are promising, indicating that quercetin acts at various points in the virus's lifecycle, we recognize the need for further research to solidify its effectiveness in treating or preventing common colds.
4
We aimed to understand if onion peel extract (OPE), which is high in quercetin, could enhance immune response in people with upper respiratory infections. In our randomized double-blind trial, we analyzed 80 participants who took either OPE or a placebo for 8 weeks.
We found that OPE improved specific cold symptoms, like hoarseness, but interestingly, it did not significantly affect immune markers or cytokine levels overall. However, those with severe symptoms showed improved immune activity with OPE. Importantly, participants experienced no significant side effects.
We found that OPE improved specific cold symptoms, like hoarseness, but interestingly, it did not significantly affect immune markers or cytokine levels overall. However, those with severe symptoms showed improved immune activity with OPE. Importantly, participants experienced no significant side effects.
9
We explored the role of flavonoid compounds, like quercetin, in reducing the frequency and severity of upper respiratory tract infections (URTIs) in healthy adults. An in-depth review of 14 studies showed that flavonoid supplementation notably reduced the incidence of URTIs by 33% and sick days by 40%.
However, we noted that changes in immune markers were minimal, indicating that while there are advantages in reducing infections, the immune response may not be significantly affected.
However, we noted that changes in immune markers were minimal, indicating that while there are advantages in reducing infections, the immune response may not be significantly affected.
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
- Cho H, Kim S, Lee SH, Park Y. Effect of onion ( L.) peel extract on natural killer cell and cytokines in a randomized, double-blind, placebo-controlled trial. Nutr Res Pract. 2024;18:33. doi:10.4162/nrp.2024.18.1.33
- Brito JCM, Lima WG, Cordeiro LPB, da Cruz Nizer WS. Effectiveness of supplementation with quercetin-type flavonols for treatment of viral lower respiratory tract infections: Systematic review and meta-analysis of preclinical studies. Phytother Res. 2021;35:4930. doi:10.1002/ptr.7122
- Xander N, Reddy Vari H, Eskandar R, Li W, Bolla S, et al. Rhinovirus-Induced SIRT-1 via TLR2 Regulates Subsequent Type I and Type III IFN Responses in Airway Epithelial Cells. J Immunol. 2019;203:2508. doi:10.4049/jimmunol.1900165
- Somerville VS, Braakhuis AJ, Hopkins WG. Effect of Flavonoids on Upper Respiratory Tract Infections and Immune Function: A Systematic Review and Meta-Analysis. Adv Nutr. 2016;7:488. doi:10.3945/an.115.010538
- Song JH, Park KS, Kwon DH, Choi HJ. Anti-human rhinovirus 2 activity and mode of action of quercetin-7-glucoside from Lagerstroemia speciosa. J Med Food. 2013;16:274. doi:10.1089/jmf.2012.2290
- Ganesan S, Faris AN, Comstock AT, Wang Q, Nanua S, et al. Quercetin inhibits rhinovirus replication in vitro and in vivo. Antiviral Res. 2012;94:258. doi:10.1016/j.antiviral.2012.03.005
