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Class landing · Contraceptives

Supplements and oral contraceptives.

The combined pill, progestogen-only pill, and the supplements that reduce contraceptive reliability.

Oral contraceptives carry one unambiguous supplement red flag and several smaller patterns. The red flag is St John’s Wort: it induces CYP3A4 and accelerates clearance of ethinyl oestradiol and most progestogens. Three randomised controlled trials (Pfrunder 2003, Hall 2003, Murphy 2005) document the effect, and documented contraceptive failures have followed. This is a hard exclusion on combined and progestogen-only pills.

Beyond that, long-term combined-pill use is associated with lower levels of folate, B6, B12, vitamin C, zinc and selenium on group-level studies. A standard multivitamin covers the gap. The class page above pre-selects the three most-prescribed UK combined and progestogen-only pills; add the supplements you take and check.

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For adults over 18. This tool gives evidence-graded information, not medical advice. Always discuss changes with your GP, especially if you take any medication, are pregnant, breastfeeding, or have a serious health condition.
Type the supplement name. Click each match to add it.
Brand or generic name works. Click each match to add it.

Something missing?

If a supplement or medication you take isn't in our autocomplete, tell us and we'll add it in the next quarterly update.

Distil's interactions database is reviewed and updated every quarter. We grade evidence transparently and publish our methodology, including every database change, at /about/methodology. This tool is information, not a substitute for clinical judgement. If you take medication and supplements together, your GP or pharmacist can review your full regimen against your medical history.