• Vitamin C: keep your total daily intake from supplements and food below 2,000 mg/day unless a clinician advises otherwise. Higher amounts can cause nausea, diarrhea, abdominal cramps, and may raise kidney-stone risk in susceptible people.
• Avoid high-dose vitamin C without medical advice if you have kidney disease, a history of calcium-oxalate kidney stones, or hereditary hemochromatosis/iron overload. Vitamin C increases iron absorption. The NIH vitamin C fact sheet discusses these cautions.
• Cancer treatment: ask your oncologist before using either supplement during chemotherapy or radiation, since antioxidants may interact with some treatment plans.
• Pregnancy, breastfeeding, chronic illness, or prescription medicines: check with a pharmacist or clinician first.
• Oral glutathione is generally tolerated, but evidence that it produces major health or skin-lightening benefits is limited and product quality varies. Do not use glutathione injections or IV “drips” outside medical supervision.

• Chemotherapy or radiation therapy: do not start high-dose vitamin C or glutathione without approval from your oncology team. Antioxidant supplements may affect some cancer treatment plans.
• Statin plus niacin therapy: high-dose vitamin C has been reported to possibly reduce the HDL-raising benefit of this combination, though the evidence is limited and mixed.
• Warfarin: rare reports suggest high-dose vitamin C could alter anticoagulant effect. If you take warfarin, do not start, stop, or substantially change vitamin C intake without checking INR more closely.
• Iron medicines or iron overload treatment: vitamin C increases absorption of non-heme iron. Use caution with iron tablets, hereditary hemochromatosis, or transfusion-related iron overload.
• Aluminum-containing antacids or phosphate binders: in people with kidney impairment, vitamin C can increase aluminum absorption, so discuss it with a clinician.
• Kidney disease or kidney-stone history: high-dose vitamin C can increase oxalate exposure. This is not exactly a drug interaction, but it changes what is safe to take.

• If you want to take them for another reason, start only one new supplement at a time and take it with food if it upsets your stomach.
• Avoid high-dose vitamin C, especially above 2,000 mg/day total.
• If your migraine includes nausea, vomiting, or poor intake, supplements may irritate your stomach and are unlikely to help the attack.
• Check with a pharmacist before use if you take prescription migraine prevention drugs, blood thinners such as warfarin, cancer treatments, or have kidney stones/kidney disease.

• Vitamin C: keep your total daily intake from supplements and food below 2,000 mg/day unless a clinician advises otherwise. Higher amounts can cause nausea, diarrhea, abdominal cramps, and may raise kidney-stone risk in susceptible people.
• Avoid high-dose vitamin C without medical advice if you have kidney disease, a history of calcium-oxalate kidney stones, or hereditary hemochromatosis/iron overload. Vitamin C increases iron absorption. The NIH vitamin C fact sheet discusses these cautions.
• Cancer treatment: ask your oncologist before using either supplement during chemotherapy or radiation, since antioxidants may interact with some treatment plans.
• Pregnancy, breastfeeding, chronic illness, or prescription medicines: check with a pharmacist or clinician first.
• Oral glutathione is generally tolerated, but evidence that it produces major health or skin-lightening benefits is limited and product quality varies. Do not use glutathione injections or IV “drips” outside medical supervision.

• Chemotherapy or radiation therapy: do not start high-dose vitamin C or glutathione without approval from your oncology team. Antioxidant supplements may affect some cancer treatment plans.
• Statin plus niacin therapy: high-dose vitamin C has been reported to possibly reduce the HDL-raising benefit of this combination, though the evidence is limited and mixed.
• Warfarin: rare reports suggest high-dose vitamin C could alter anticoagulant effect. If you take warfarin, do not start, stop, or substantially change vitamin C intake without checking INR more closely.
• Iron medicines or iron overload treatment: vitamin C increases absorption of non-heme iron. Use caution with iron tablets, hereditary hemochromatosis, or transfusion-related iron overload.
• Aluminum-containing antacids or phosphate binders: in people with kidney impairment, vitamin C can increase aluminum absorption, so discuss it with a clinician.
• Kidney disease or kidney-stone history: high-dose vitamin C can increase oxalate exposure. This is not exactly a drug interaction, but it changes what is safe to take.

• If you want to take them for another reason, start only one new supplement at a time and take it with food if it upsets your stomach.
• Avoid high-dose vitamin C, especially above 2,000 mg/day total.
• If your migraine includes nausea, vomiting, or poor intake, supplements may irritate your stomach and are unlikely to help the attack.
• Check with a pharmacist before use if you take prescription migraine prevention drugs, blood thinners such as warfarin, cancer treatments, or have kidney stones/kidney disease.

If you still want glutathione

Vitamin C

• Limcee 500 mg by Abbott
• Celin 500 mg by GSK