Last update
5/5/2025

Overview

SCIENTIFIC SCORE
Moderately Effective
Based on 2 Researches
8
USERS' SCORE
Good
Based on 6 Reviews
8.2

Top Medical Research Studies

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.
Read More
9
Vitamin C improves cold tolerance
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.
Read More

Most Useful Reviews

7.5
Highly protective
32 people found this helpful
Great product; I've been using this for years without getting sick, especially in winter when everyone else falls ill. I can't get the flu vaccine, but this does a fantastic job of protecting me during rough months of the cold. I work in healthcare and I can honestly say I'm often the only one who doesn't get sick or, when I do, it’s less severe than with others. I highly recommend this product.
Read More
7.5
Cold prevention benefits
13 people found this helpful
Gentle yet effective. This is one of my two favourite types of vitamin C. I’ve been using Ester C for some time now and find it easy on the stomach, requiring no food and causing no acidity or reflux. Because of the low dosage, I can take it multiple times throughout the day. My most recent cold, which I expected to be extensive, didn’t last long, and symptoms were tolerable. Moreover, I have noticed it keeps me well even around those feeling under the weather.
Read More
9
Effective against cold
2 people found this helpful
I love mine; they're not difficult to swallow, just for those who complain about the size. I bought these for my sister, but I take the 1000 mg, which are the largest pills. They knock a cold, stuffy nose, cough, and congestion straight out. People have put bigger things in their mouths and swallowed them. If you feel like you might choke, just take a big gulp of water with it. You're done before you know it.
Read More

Medical Researches

SCIENTIFIC SCORE
Moderately Effective
Based on 2 Researches
8
  • All Researches
9
Vitamin C improves cold tolerance
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.
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.
Read More

User Reviews

USERS' SCORE
Good
Based on 6 Reviews
8.2
  • All Reviews
  • Positive Reviews
  • Negative Reviews
7.5
Highly protective
32 people found this helpful
Great product; I've been using this for years without getting sick, especially in winter when everyone else falls ill. I can't get the flu vaccine, but this does a fantastic job of protecting me during rough months of the cold. I work in healthcare and I can honestly say I'm often the only one who doesn't get sick or, when I do, it’s less severe than with others. I highly recommend this product.
Read More
7.5
Cold prevention benefits
13 people found this helpful
Gentle yet effective. This is one of my two favourite types of vitamin C. I’ve been using Ester C for some time now and find it easy on the stomach, requiring no food and causing no acidity or reflux. Because of the low dosage, I can take it multiple times throughout the day. My most recent cold, which I expected to be extensive, didn’t last long, and symptoms were tolerable. Moreover, I have noticed it keeps me well even around those feeling under the weather.
Read More
9
Effective against cold
2 people found this helpful
I love mine; they're not difficult to swallow, just for those who complain about the size. I bought these for my sister, but I take the 1000 mg, which are the largest pills. They knock a cold, stuffy nose, cough, and congestion straight out. People have put bigger things in their mouths and swallowed them. If you feel like you might choke, just take a big gulp of water with it. You're done before you know it.
Read More
10
Cold-free for years
1 people found this helpful
I haven't had a cold or flu in the past five years since I've been taking these vitamins.
Read More
6
Shortened colds
1 people found this helpful
Ester C is a helpful supplement for improving immune resistance and shortening colds. I take two a day.
Read More

Frequently Asked Questions

No FAQs are available for this product and symptom.

References

  1. Hemilä H, Chalker E. Vitamin C for the common cold and pneumonia. Pol Arch Intern Med. 2025;135. 10.20452/pamw.16926
  2. 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. 10.3390/ijms251810093
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