Is Vitamin C (Ascorbic Acid) Safe with Ethinyl estradiol?
Free · No account · based on published sources including NIH ODS, FDA drug labels, and peer-reviewed literature
Avoid taking high-dose Vitamin C (≥1000 mg/day) consistently with OCs. If supplementing, keep doses at 200–500 mg/day. Do not abruptly stop high-dose Vitamin C as this may transiently lower estrogen levels.
Why this interaction occurs
High-dose ascorbic acid competes with ethinyl estradiol for sulfation in the gut wall (via sulfotransferase enzymes), potentially increasing ethinyl estradiol bioavailability and estrogen-related side effects. Sudden discontinuation of high-dose Vitamin C may reduce estrogen levels and compromise contraceptive efficacy transiently.
Evidence
Evidence level: moderate.
Reported safety data
The FDA’s adverse event reporting system (FAERS) has received 240,329 reports mentioning Ethinyl estradiol. This reflects reported cases involving the medication in general — not confirmed causation, and not specific to the Ethinyl estradiol + supplement combination on this page.
FAERS reports are voluntary and cannot prove that a drug caused an event. Do not use report counts to assess the safety of this specific drug-supplement pair.
Frequently asked questions
Related interactions
All Vitamin C (Ascorbic Acid) interactions → · All Ethinyl estradiol interactions →
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Educational only — not medical advice.
Always confirm with your doctor or pharmacist.