Last update
3/17/2026
Reviewed By
Overview
SCIENTIFIC SCORE
Possibly Effective
Based on 8 Researches
7.5
USERS' SCORE
Good
Based on 20 Reviews
8.1
Supplement Facts
Serving Size: 1 Veggie Capsule
Amount Per Serving
%DV
Vitamin C (as Q®-C ascorbic acid)
500 mg
556%
Top Medical Research Studies
8
We examined the effects of vitamin C on pneumonia caused by the influenza virus, specifically the H1N1 strain, in mice under stress. The study found that when exposed to restraint stress, the mice experienced increased mortality and more severe pneumonia symptoms.
However, by giving them oral vitamin C at doses of 125 and 250 mg/kg, we observed a significant reduction in these severe outcomes. Vitamin C seemed to modulate the expression of certain genes related to the immune response, such as MAVS and IRF3, and increased the expression of NF-κB, which plays a key role in the body's antiviral defense.
Our research suggested that vitamin C's protective effects might stem from its ability to inhibit excess cortisol production in the adrenal gland, which is often elevated due to stress. By lowering cortisol levels, vitamin C may help reduce susceptibility to influenza infections, making it a potential ally during the flu season, especially for those experiencing stress.
Through these findings, we highlighted a new mechanism for how vitamin C can be beneficial during influenza infections, particularly for those who are feeling overwhelmed.
However, by giving them oral vitamin C at doses of 125 and 250 mg/kg, we observed a significant reduction in these severe outcomes. Vitamin C seemed to modulate the expression of certain genes related to the immune response, such as MAVS and IRF3, and increased the expression of NF-κB, which plays a key role in the body's antiviral defense.
Our research suggested that vitamin C's protective effects might stem from its ability to inhibit excess cortisol production in the adrenal gland, which is often elevated due to stress. By lowering cortisol levels, vitamin C may help reduce susceptibility to influenza infections, making it a potential ally during the flu season, especially for those experiencing stress.
Through these findings, we highlighted a new mechanism for how vitamin C can be beneficial during influenza infections, particularly for those who are feeling overwhelmed.
Read More
8
We explored the impact of high doses of Vitamin C on cold and flu symptoms in a controlled study involving 752 students. While 463 participants made up the control group and received standard treatments, the 252 in the test group took 1000 mg of Vitamin C at set intervals.
After comparing reports from both groups, we observed that those who took Vitamin C experienced less severe and fewer symptoms compared to those who did not. This suggests that Vitamin C could be a helpful supplement in managing flu symptoms.
After comparing reports from both groups, we observed that those who took Vitamin C experienced less severe and fewer symptoms compared to those who did not. This suggests that Vitamin C could be a helpful supplement in managing flu symptoms.
Read More
8
Vitamin C triterpene flu inhibitors
We recently explored the potential of novel compounds that are combinations of L-ascorbic acid, commonly known as vitamin C, and pentacyclic triterpenes in battling the flu. The study focused on compounds we created and tested against the influenza virus in MDCK cells, particularly looking at their effectiveness and any possible side effects.
Among all the compounds we evaluated, one stood out: the 2,3-O,O-dibenzyl-6-deoxy-L-ascorbic acid-betulinic acid conjugate. It displayed significant anti-influenza activity with an effective concentration (EC50) of just 8.7 μM and was not toxic to the cells used in our testing. This suggests that combining vitamin C with these triterpenes might enhance their ability to fight the flu virus, marking an exciting avenue for further research.
We also discovered that this particular compound acts early in the influenza lifecycle, interfering with the virus's ability to attach to cells. We confirmed this by observing that it inhibited the hemagglutination—a crucial step that allows the virus to spread. Our findings indicate that L-ascorbic acid-conjugated triterpenes hold promise as potential anti-influenza agents, specifically targeting viral entry and enhancing the effectiveness of treatment strategies.
Among all the compounds we evaluated, one stood out: the 2,3-O,O-dibenzyl-6-deoxy-L-ascorbic acid-betulinic acid conjugate. It displayed significant anti-influenza activity with an effective concentration (EC50) of just 8.7 μM and was not toxic to the cells used in our testing. This suggests that combining vitamin C with these triterpenes might enhance their ability to fight the flu virus, marking an exciting avenue for further research.
We also discovered that this particular compound acts early in the influenza lifecycle, interfering with the virus's ability to attach to cells. We confirmed this by observing that it inhibited the hemagglutination—a crucial step that allows the virus to spread. Our findings indicate that L-ascorbic acid-conjugated triterpenes hold promise as potential anti-influenza agents, specifically targeting viral entry and enhancing the effectiveness of treatment strategies.
Read More
Most Useful Reviews
9
Flu-A recovery
1 people found this helpful
Good! I’ve tried other 500mg capsules, but this one is slightly smaller. I have many caps to take daily, so I prefer a smaller one. It helped me fight Flu-A in 2015, recovering much better and faster than others who took Tamiflu.
Read More
9
Immunity boost
Works great for improving immunity. It effectively keeps the flu away.
Read More
9
Flu friend
The quality is excellent, with ingredients as mentioned. It comes in a 120-tablet, 500mg package. Normally, one pill is taken daily. It’s advised to skip it if the food is rich in vitamin C but should still be kept in the home pharmacy. I have purchased it many times and highly recommend it; it has become my 'friend of the flu.'
Read More
Medical Researches
SCIENTIFIC SCORE
Possibly Effective
Based on 8 Researches
7.5
- All Researches
9
We set out to discover how red ginseng and vitamin C work together to enhance immune cell function and fight off viral infections like the flu. In our investigation, we treated human immune cells and specific types of mice unable to produce vitamin C, looking closely at their reaction to influenza A virus/H1N1.
Our findings were quite promising. We observed that both red ginseng and vitamin C elevated the activation levels of immune cells, particularly T-cells and natural killer (NK) cells, known for their vital role in combating viruses. This combination not only helped boost immune cell activity but also reduced lung inflammation caused by the influenza virus, which is crucial for better survival rates during infections.
In cases where vitamin C levels were low in a specific mouse model, we noted that the added nutrients significantly improved their condition. They experienced reduced viral load and inflammation in their lungs after receiving red ginseng and vitamin C, compared to those without this supplementation. These insights suggest that while red ginseng and vitamin C collectively support immune health, the interplay of these substances can be crucial in managing flu infections effectively.
Our findings were quite promising. We observed that both red ginseng and vitamin C elevated the activation levels of immune cells, particularly T-cells and natural killer (NK) cells, known for their vital role in combating viruses. This combination not only helped boost immune cell activity but also reduced lung inflammation caused by the influenza virus, which is crucial for better survival rates during infections.
In cases where vitamin C levels were low in a specific mouse model, we noted that the added nutrients significantly improved their condition. They experienced reduced viral load and inflammation in their lungs after receiving red ginseng and vitamin C, compared to those without this supplementation. These insights suggest that while red ginseng and vitamin C collectively support immune health, the interplay of these substances can be crucial in managing flu infections effectively.
Read More
8
We explored the effects of high-dose vitamin C on blood flow during inflammation caused by endotoxin. In a balanced, placebo-controlled crossover study with 36 male subjects, we examined how vitamin C administration impacted vascular function. After administering lipopolysaccharide (LPS), participants experienced flu-like symptoms and a significant drop in blood flow response.
However, we found that high-dose vitamin C improved this blood flow response, suggesting it can help counteract issues related to inflammation. This paves the way for further research on vitamin C's benefits in similar conditions.
However, we found that high-dose vitamin C improved this blood flow response, suggesting it can help counteract issues related to inflammation. This paves the way for further research on vitamin C's benefits in similar conditions.
Read More
8
We explored the impact of high doses of Vitamin C on cold and flu symptoms in a controlled study involving 752 students. While 463 participants made up the control group and received standard treatments, the 252 in the test group took 1000 mg of Vitamin C at set intervals.
After comparing reports from both groups, we observed that those who took Vitamin C experienced less severe and fewer symptoms compared to those who did not. This suggests that Vitamin C could be a helpful supplement in managing flu symptoms.
After comparing reports from both groups, we observed that those who took Vitamin C experienced less severe and fewer symptoms compared to those who did not. This suggests that Vitamin C could be a helpful supplement in managing flu symptoms.
Read More
8
Vitamin C triterpene flu inhibitors
We recently explored the potential of novel compounds that are combinations of L-ascorbic acid, commonly known as vitamin C, and pentacyclic triterpenes in battling the flu. The study focused on compounds we created and tested against the influenza virus in MDCK cells, particularly looking at their effectiveness and any possible side effects.
Among all the compounds we evaluated, one stood out: the 2,3-O,O-dibenzyl-6-deoxy-L-ascorbic acid-betulinic acid conjugate. It displayed significant anti-influenza activity with an effective concentration (EC50) of just 8.7 μM and was not toxic to the cells used in our testing. This suggests that combining vitamin C with these triterpenes might enhance their ability to fight the flu virus, marking an exciting avenue for further research.
We also discovered that this particular compound acts early in the influenza lifecycle, interfering with the virus's ability to attach to cells. We confirmed this by observing that it inhibited the hemagglutination—a crucial step that allows the virus to spread. Our findings indicate that L-ascorbic acid-conjugated triterpenes hold promise as potential anti-influenza agents, specifically targeting viral entry and enhancing the effectiveness of treatment strategies.
Among all the compounds we evaluated, one stood out: the 2,3-O,O-dibenzyl-6-deoxy-L-ascorbic acid-betulinic acid conjugate. It displayed significant anti-influenza activity with an effective concentration (EC50) of just 8.7 μM and was not toxic to the cells used in our testing. This suggests that combining vitamin C with these triterpenes might enhance their ability to fight the flu virus, marking an exciting avenue for further research.
We also discovered that this particular compound acts early in the influenza lifecycle, interfering with the virus's ability to attach to cells. We confirmed this by observing that it inhibited the hemagglutination—a crucial step that allows the virus to spread. Our findings indicate that L-ascorbic acid-conjugated triterpenes hold promise as potential anti-influenza agents, specifically targeting viral entry and enhancing the effectiveness of treatment strategies.
Read More
8
We examined the effects of vitamin C on pneumonia caused by the influenza virus, specifically the H1N1 strain, in mice under stress. The study found that when exposed to restraint stress, the mice experienced increased mortality and more severe pneumonia symptoms.
However, by giving them oral vitamin C at doses of 125 and 250 mg/kg, we observed a significant reduction in these severe outcomes. Vitamin C seemed to modulate the expression of certain genes related to the immune response, such as MAVS and IRF3, and increased the expression of NF-κB, which plays a key role in the body's antiviral defense.
Our research suggested that vitamin C's protective effects might stem from its ability to inhibit excess cortisol production in the adrenal gland, which is often elevated due to stress. By lowering cortisol levels, vitamin C may help reduce susceptibility to influenza infections, making it a potential ally during the flu season, especially for those experiencing stress.
Through these findings, we highlighted a new mechanism for how vitamin C can be beneficial during influenza infections, particularly for those who are feeling overwhelmed.
However, by giving them oral vitamin C at doses of 125 and 250 mg/kg, we observed a significant reduction in these severe outcomes. Vitamin C seemed to modulate the expression of certain genes related to the immune response, such as MAVS and IRF3, and increased the expression of NF-κB, which plays a key role in the body's antiviral defense.
Our research suggested that vitamin C's protective effects might stem from its ability to inhibit excess cortisol production in the adrenal gland, which is often elevated due to stress. By lowering cortisol levels, vitamin C may help reduce susceptibility to influenza infections, making it a potential ally during the flu season, especially for those experiencing stress.
Through these findings, we highlighted a new mechanism for how vitamin C can be beneficial during influenza infections, particularly for those who are feeling overwhelmed.
Read More
User Reviews
USERS' SCORE
Good
Based on 20 Reviews
8.1
- All Reviews
- Positive Reviews
- Negative Reviews
9
Flu-A recovery
1 people found this helpful
Good! I’ve tried other 500mg capsules, but this one is slightly smaller. I have many caps to take daily, so I prefer a smaller one. It helped me fight Flu-A in 2015, recovering much better and faster than others who took Tamiflu.
Read More
9
Immunity boost
Works great for improving immunity. It effectively keeps the flu away.
Read More
9
Flu friend
The quality is excellent, with ingredients as mentioned. It comes in a 120-tablet, 500mg package. Normally, one pill is taken daily. It’s advised to skip it if the food is rich in vitamin C but should still be kept in the home pharmacy. I have purchased it many times and highly recommend it; it has become my 'friend of the flu.'
Read More
9
Highly recommend
Top product! I have used it for six years. It is excellent for immunity, especially during flu season. I highly recommend it.
Read More
9
Quick recovery
Effective! Every time I'm about to get sick, I take it. It also helps me recover quicker after a serious flu. I’ve bought it several times. Value for money.
Read More
Frequently Asked Questions
7.5
Effective treatment
Excellent. I found it very effective for the flu, although it took about three days to feel better.
7.5
Recover quickly
3 people found this helpful
Its quality is high, with a large quantity that lasts long. It is gentle on the stomach and does not cause acidity. I notice a boost in my immunity when taking it, which brightens my skin as well. Its taste and smell are pleasant. When I have the flu, I usually recover within a couple of days after taking it. I absolutely loved this product.
9
Cold prevention
My favourite Vitamin C! I feel its effects notably well when treating my partner with a loading dose. If he starts to catch a cold in the evening, I give him 3-4 g, and by morning, he feels perfectly fine.
6
No flu observed
7 people found this helpful
Vitamin C is well-known for benefiting skin and overall health. I use it daily with food and since incorporating it, I haven't had the seasonal flu for two years. Additionally, my skin looks clearer. Many doctors on Twitter recommend it as the best vitamin for public health, containing 1000 mg per dose, and I have been using two doses of it.
9
Maintains immunity
I’ve ordered Vitamin C from this manufacturer multiple times and prefer it over others. The capsules are convenient compared to pills. Following my doctor's advice, I take one capsule daily, and during flu seasons, I take two. I am satisfied with the quality and manage the cold season without issues, despite having chronic illnesses.
9
Healthy family
1 people found this helpful
Since my multi-vitamin only contains 500 mg of Vitamin C, I take Doctor’s Best Vitamin C 500 mg once or twice daily, ensuring a daily bowel movement. Since starting it, I've remained cold-free, and I also give it to my son, who didn't get sick even during a flu outbreak at school last year. The price is reasonable, and we consider it essential.
8
We examined the effects of vitamin C on pneumonia caused by the influenza virus, specifically the H1N1 strain, in mice under stress. The study found that when exposed to restraint stress, the mice experienced increased mortality and more severe pneumonia symptoms.
However, by giving them oral vitamin C at doses of 125 and 250 mg/kg, we observed a significant reduction in these severe outcomes. Vitamin C seemed to modulate the expression of certain genes related to the immune response, such as MAVS and IRF3, and increased the expression of NF-κB, which plays a key role in the body's antiviral defense.
Our research suggested that vitamin C's protective effects might stem from its ability to inhibit excess cortisol production in the adrenal gland, which is often elevated due to stress. By lowering cortisol levels, vitamin C may help reduce susceptibility to influenza infections, making it a potential ally during the flu season, especially for those experiencing stress.
Through these findings, we highlighted a new mechanism for how vitamin C can be beneficial during influenza infections, particularly for those who are feeling overwhelmed.
However, by giving them oral vitamin C at doses of 125 and 250 mg/kg, we observed a significant reduction in these severe outcomes. Vitamin C seemed to modulate the expression of certain genes related to the immune response, such as MAVS and IRF3, and increased the expression of NF-κB, which plays a key role in the body's antiviral defense.
Our research suggested that vitamin C's protective effects might stem from its ability to inhibit excess cortisol production in the adrenal gland, which is often elevated due to stress. By lowering cortisol levels, vitamin C may help reduce susceptibility to influenza infections, making it a potential ally during the flu season, especially for those experiencing stress.
Through these findings, we highlighted a new mechanism for how vitamin C can be beneficial during influenza infections, particularly for those who are feeling overwhelmed.
References
- Aschauer S, Gouya G, Klickovic U, Storka A, Weisshaar S, et al. Effect of systemic high dose vitamin C therapy on forearm blood flow reactivity during endotoxemia in healthy human subjects. Vascul Pharmacol. 2014;61:25. 10.1016/j.vph.2014.01.007
- Gorton HC, Jarvis K. The effectiveness of vitamin C in preventing and relieving the symptoms of virus-induced respiratory infections. J Manipulative Physiol Ther. 1999;22:530. PubMed
- Abioye AI, Bromage S, Fawzi W. Effect of micronutrient supplements on influenza and other respiratory tract infections among adults: a systematic review and meta-analysis. BMJ Glob Health. 2021;6. 10.1136/bmjgh-2020-003176
- Márquez-Domínguez L, Reyes-Leyva J, Herrera-Camacho I, Santos-López G, Scior T. Five Novel Non-Sialic Acid-Like Scaffolds Inhibit In Vitro H1N1 and H5N2 Neuraminidase Activity of Influenza a Virus. Molecules. 2020;25. 10.3390/molecules25184248
- Kim H, Jang M, Kim Y, Choi J, Jeon J, et al. Red ginseng and vitamin C increase immune cell activity and decrease lung inflammation induced by influenza A virus/H1N1 infection. J Pharm Pharmacol. 2016;68:406. 10.1111/jphp.12529
- Wang H, Xu R, Shi Y, Si L, Jiao P, et al. Design, synthesis and biological evaluation of novel L-ascorbic acid-conjugated pentacyclic triterpene derivatives as potential influenza virus entry inhibitors. Eur J Med Chem. 2016;110:376. 10.1016/j.ejmech.2016.01.005
- Cai Y, Li YF, Tang LP, Tsoi B, Chen M, et al. A new mechanism of vitamin C effects on A/FM/1/47(H1N1) virus-induced pneumonia in restraint-stressed mice. Biomed Res Int. 2015;2015:675149. 10.1155/2015/675149
- Raja K, Prabahar A, Selvakumar S, Raja TK. In Silico Analysis to Compare the Effectiveness of Assorted Drugs Prescribed for Swine flu in Diverse Medicine Systems. Indian J Pharm Sci. 2014;76:10. PubMed
Data last updated:
