NutriStack
Fluticasone Nasal and St. John's Wort, a conflict.
St. John's Wort induces CYP3A4, the main pathway that clears fluticasone. With daily nasal fluticasone, this may lower steroid exposure and reduce rhinitis or nasal polyp symptom control, though the effect is likely product- and dose-dependent.
One pair, every claim cited. The two substances, the type, the mechanism, the recommendation, and the primary literature.
Same shape as the other 1,729 pairs in the public database.
From the interaction database
What the row says.
Every entry follows the same shape: what is happening, the mechanism, the recommendation, and the primary literature.
At a glance
- Substances
- Fluticasone Nasal and St. John's Wort
- Pair type
- Conflict
- Evidence (highest tier)
- Moderate
- Source citations
- 2 sources
- Stack Score effect
- −10 to your Stack Score (per scored conflict row).
- Scope
- Supplement × Prescription
- Last verified
- May 30, 2026
Conflict · Moderate evidence
Conflict
What is happening. St. John's Wort induces CYP3A4, the main pathway that clears fluticasone. With daily nasal fluticasone, this may lower steroid exposure and reduce rhinitis or nasal polyp symptom control, though the effect is likely product- and dose-dependent.
Mechanism. High-hyperforin St. John's Wort induces CYP3A4 expression and activity. Fluticasone is extensively cleared by CYP3A4, so induction may increase metabolism and lower exposure after swallowed or absorbed nasal doses.
Recommendation. Avoid starting St. John's Wort if nasal fluticasone control is important, or monitor symptoms after any change. If congestion, sneezing, or nasal polyp symptoms worsen after starting St. John's Wort, ask about adjusting therapy rather than simply increasing steroid dose on your own.
Sources (2)
- Whitten DL, Myers SP, Hawrelak JA, Wohlmuth H. The effect of St John's wort extracts on CYP3A: a systematic review of prospective clinical trials. Br J Clin Pharmacol. 2006;62(5):512-526. PMID 17010103
- Foisy MM, Yakiwchuk EM, Chiu I, Singh AE. Adrenal suppression and Cushing's syndrome secondary to an interaction between ritonavir and fluticasone: a review of the literature. HIV Med. 2008;9(6):389-396. PMID 18459946
Stack Score
How this pair moves the number.
Effect on the composite score
If both Fluticasone Nasal and St. John's Wort are in the same stack, this pair applies −10 to your Stack Score (per scored conflict row).
The full algorithm, the clamping rules, and four worked stacks are documented at /methodology/stack-score.
Check your full routine
One pair was the worked example. NutriStack runs every pair in your stack at once.
Drop in your supplements and prescriptions and the public database surfaces every interaction, synergy, timing rule, and contraindication, every one linked to its primary source.