“IV vitamin C boosts your immune system.”
IV vitamin C drips have not been shown to boost the immune system in healthy people.
An IV vitamin C drip will not make your immune system stronger or keep you from getting sick. Paying for one adds needle risks without a proven benefit.
If you are thinking about a vitamin C drip to avoid getting sick, you can skip it.
Safety note: High-dose IV vitamin C can break down red blood cells in people with G6PD deficiency, an inherited enzyme problem, and very large or repeated doses have been linked to kidney damage from oxalate, a breakdown product. Any IV drip also carries procedure risks: severe infections, including deaths, have been reported from poorly sterilized equipment, and drips can overload the body with fluid in people with heart conditions or high blood pressure.
Talk to a healthcare professional if: you have G6PD deficiency, kidney disease, a heart condition or high blood pressure, and are thinking about an IV vitamin C drip; or you keep getting sick and want to know why.
Large trials show daily vitamin C does not prevent colds in everyday life, and in people with severe infection, IV vitamin C did not help and a large trial found worse outcomes. Confidence is limited because no trial has tested IV vitamin C drips in healthy people.
IV vitamin C drips have not been shown to boost the immune system in healthy people. Vitamin C does not prevent colds, and IV doses have not helped even people with severe infections.
A vein drip can raise blood vitamin C far above what pills can reach, but a higher blood level is not proof of better immunity. A medical reference notes that what "boost the immune system" means for these drips, or how it could happen, is not clear. In a Cochrane review of 29 trial comparisons with 11,306 people, taking vitamin C by mouth every day did not lower the chance of catching a cold in the general public (risk ratio 0.97); colds were about 8 percent shorter in adults. In hospital patients with severe infection, a different situation, a trial of 872 adults found that IV vitamin C did not help: 44.5% died or had lasting organ failure by day 28, compared with 38.5% on placebo. A 2026 review of 31 reviews of sepsis trials concluded the evidence does not support routine IV vitamin C.
- Hemilä H, Chalker E. Vitamin C for preventing and treating the common cold. Cochrane Database of Systematic Reviews. 2013;(1):CD000980. DOI: 10.1002/14651858.CD000980.pub4. PMID: 23440782. PMCID: PMC8078152
- Lamontagne F, Masse MH, Menard J, et al.; LOVIT Investigators and the Canadian Critical Care Trials Group. Intravenous Vitamin C in Adults with Sepsis in the Intensive Care Unit. New England Journal of Medicine. 2022;386(25):2387-2398. DOI: 10.1056/NEJMoa2200644. PMID: 35704292
- Vera-Ponce VJ, Ballena-Caicedo J, Valladolid-Sandoval LAM, et al. Monotherapy or combinations? Intravenous vitamin C in sepsis and septic shock: An umbrella review of 31 systematic reviews. PLoS One. 2026;21(7):e0351072. DOI: 10.1371/journal.pone.0351072. PMID: 42384633. PMCID: PMC13322531
- Alangari A, Arif J, Al Qureshah F, Alkhodairy F. Clinical benefits and risks of high-dose intravenous vitamin C: a systematic review. Journal of Medicine and Life. 2026;19(1):16-23. DOI: 10.25122/jml-2025-0176. PMID: 41815850. PMCID: PMC12973930
- Shane-McWhorter L. Intravenous Vitamin Therapy (Myers' Cocktail). Merck Manual Consumer Version. Last updated July 2025