PlainPill

Vitamin C

People mainly take Vitamin C for energy, skin & hair, immunity. Based on 458 first-hand reports and 738 meta-analyses & systematic reviews in the medical literature. Ranked #146 of 1,974 overall.

47
User score
Mostly positive
19% positive4% mixed3% negative73% unclear

Of reports that state an outcome, 73% are positive.

Clinical research
AStrong research base
738
meta-analyses
2,072
RCTs
69,592
papers

What Vitamin C does, according to users

Of the people who reported each effect, the share who said it got better.

What the research says

Systematic reviews and meta-analyses from PubMed, with their published conclusions.

AStrong research base

3+ meta-analyses or systematic reviews and 10+ randomized controlled trials in humans. The grade measures how much human research exists — read the conclusions below for what it found.

Cochrane Database Syst Rev · 2013 · Meta-analysis / systematic review
Vitamin C for preventing and treating the common cold

Conclusion: The failure of vitamin C supplementation to reduce the incidence of colds in the general population indicates that routine vitamin C supplementation is not justified, yet vitamin C may be useful for people exposed to brief periods of severe physical exercise. Regular supplementation trials have shown that vitamin C reduces the duration of colds, but this was not replicated in the few therapeutic trials that have been carried out. Nevertheless, given the consistent effect of vitamin C on the duration and severity of colds in the regular supplementation studies, and the low cost and safety, it m

PubMed 23440782 ↗
Clin Nutr · 2022 · Meta-analysis / systematic review
ESPEN micronutrient guideline

Conclusion: This guideline should enable addressing suboptimal and deficient status of a bundle of MNs in at-risk diseases. In particular, it offers practical advice on MN provision and monitoring during nutritional support.

PubMed 35365361 ↗

Dosage people report

As stated by users — not a recommendation. Follow the label or your doctor.

2000 mgdaily
500 mgdaily
1 gas reported
1080 mgdaily
500 mg2x daily
500 mgbefore and after meals

Reported side effects

How often each side effect came up across all reports.

kidney stones ×5stomach issues ×2bone pain ×2kidney stone ×2copper depletion ×1injection site ×1sleep apnea ×1heart palpitations ×1

What users say

Verbatim quotes, shortened only — each links to the original discussion.

Other options for energy

User data from public discussions; research from PubMed. Information only, not medical advice — talk to a doctor before starting, stopping or combining anything. Data updated October 2, 2026. How we rate