After a drip and risks

During the infusion

Vitamin C given faster than 250 mg a minute may cause faintness, nausea, flushing, dizziness and headache. NAD+ drips caused stomach symptoms, faster heart rate and chest pressure that ended when the infusion stopped.[1][2]

At the needle site

Pain and swelling at the site may follow. In a survey of 9,328 IV vitamin C patients, 101 had side effects, mostly minor: 59 lethargy or fatigue, 21 change in mental status and 6 vein irritation.[1][2]

First hours

Fever, chills, body aches, dizziness or low blood pressure after a drip can signal endotoxin from a contaminated product. In a 2025 case, a woman collapsed with a fever above 41 C within an hour of a glutathione infusion.[1][2][3]

First 24 hours

Vitamin C can upset lab tests, including blood and urine glucose. The Ascor label advises waiting 24 hours after infusion for these tests, and some glucose meters read falsely high.[1][2]

First 3 days

In 14 reported cases of vitamin C hemolysis, 78.6% had complications within 3 days, and 71.4% had G6PD deficiency.[1]

When to get care

CDC advises contacting a provider for symptoms after a recent injection and seeking emergency care for severe symptoms. Adverse events can be reported to FDA MedWatch.[1]

Contaminated compounded drips

Products made with dietary supplement grade glutathione caused endotoxin reactions: 8 patients in 2018-2019, at least 30 in 2026. CDC counted more than 25 ill in Texas, Washington, Florida and New York, at least 3 hospitalized and 1 treated in intensive care for shock.[1][2][3]

Kidney damage from vitamin C

Oxalate nephropathy and kidney stones follow prolonged high doses. A 74-year-old woman given 100 g a week for 6 weeks needed lifelong dialysis. Kidney disease, past oxalate stones and older age raise the risk.[1][2]

Hemolysis in G6PD deficiency

Vitamin C can destroy red blood cells in people with G6PD deficiency. Of 14 reported hemolysis cases, 71.4% had G6PD deficiency and doses ranged from 1 to 200 g a day.[1][2][3]

False blood sugar readings

High-dose IV vitamin C caused falsely high readings on 2 of 3 hospital glucose meters tested.[1][2]

Allergic and skin reactions

IV thiamine caused 1 major reaction in 1,070 doses. One serious anaphylaxis occurred on vitamin C in LOVIT. Stevens-Johnson syndrome followed a glutathione, vitamin C and vitamin D infusion in a 33-year-old woman.[1][2][3]

IV catheter problems

35% to 50% of peripheral IV catheters fail. Phlebitis was reported in IV vitamin C use.[1][2]

Harm in serious illness

In sepsis, IV vitamin C raised death or organ dysfunction to 44.5% against 38.5% on placebo. Trials in COVID-19 stopped for harm and futility.[1][2]

NAD+ infusion symptoms

Stomach symptoms, faster heart rate and chest pressure during NAD+ infusions led to longer infusion times.[1]