Interaction Checker

St. John's wort interactions

St. John's wort is one of the most interaction-prone supplements: it induces CYP3A4 and P-glycoprotein, lowering levels of many prescription drugs.

St. John's wort has 88 documented interactions across the FDA labels and fact sheets we index: 86 major, 2 moderate, 0 minor, and 0 where a label reports no significant interaction. Each entry below quotes the sentence behind it. This herbal and supplement page is a starting point, not a verdict for your situation.

Major interactions (86)

  • AlprazolambenzodiazepineMajor

    St. John's wort can weaken these medicines by speeding up their breakdown, which can mean organ rejection, clots, or loss of effect. (NCCIH, St. John's Wort)

  • Amitriptylinetricyclic antidepressantMajor

    Combining St. John's wort with antidepressants and other serotonergic drugs increases the risk of serotonin syndrome. (NCCIH, St. John's Wort)

  • Amlodipinedihydropyridine calcium channel blockerMajor

    St. John's wort can weaken these medicines by speeding up their breakdown, which can mean organ rejection, clots, or loss of effect. (NCCIH, St. John's Wort)

  • ApixabananticoagulantMajor

    St. John's wort can weaken these medicines by speeding up their breakdown, which can mean organ rejection, clots, or loss of effect. (NCCIH, St. John's Wort)

  • AtorvastatinstatinMajor

    St. John's wort can weaken these medicines by speeding up their breakdown, which can mean organ rejection, clots, or loss of effect. (NCCIH, St. John's Wort)

  • Bictegravir, emtricitabine, and tenofovir alafenamideantiretroviralMajor

    St. John's wort can lower blood levels of some HIV medicines enough to cause treatment failure. (NCCIH, St. John's Wort)

  • BupropionantidepressantMajor

    Combining St. John's wort with antidepressants and other serotonergic drugs increases the risk of serotonin syndrome. (NCCIH, St. John's Wort)

  • Buspironeserotonergic drugMajor

    Combining St. John's wort with antidepressants and other serotonergic drugs increases the risk of serotonin syndrome. (NCCIH, St. John's Wort)

  • CitalopramSSRIMajor

    Combining St. John's wort with antidepressants and other serotonergic drugs increases the risk of serotonin syndrome. (NCCIH, St. John's Wort)

  • Conjugated estrogensestrogenMajor

    St. John's wort can make birth control pills less effective. (NCCIH, St. John's Wort)

  • Cyclobenzaprinemuscle relaxantMajor

    Combining St. John's wort with antidepressants and other serotonergic drugs increases the risk of serotonin syndrome. (NCCIH, St. John's Wort)

  • CyclosporineimmunosuppressantMajor

    St. John's wort can weaken these medicines by speeding up their breakdown, which can mean organ rejection, clots, or loss of effect. (NCCIH, St. John's Wort)

  • DabigatrananticoagulantMajor

    St. John's wort can weaken these medicines by speeding up their breakdown, which can mean organ rejection, clots, or loss of effect. (NCCIH, St. John's Wort)

  • DesvenlafaxineSNRIMajor

    Combining St. John's wort with antidepressants and other serotonergic drugs increases the risk of serotonin syndrome. (NCCIH, St. John's Wort)

  • Dextromethorphanserotonergic drugMajor

    Combining St. John's wort with antidepressants and other serotonergic drugs increases the risk of serotonin syndrome. (NCCIH, St. John's Wort)

  • Digoxindigitalis glycosideMajor

    St. John's wort can weaken these medicines by speeding up their breakdown, which can mean organ rejection, clots, or loss of effect. (NCCIH, St. John's Wort)

  • Dihydroergotamineergot alkaloidMajor

    Combining St. John's wort with antidepressants and other serotonergic drugs increases the risk of serotonin syndrome. (NCCIH, St. John's Wort)

  • DolutegravirantiretroviralMajor

    John’s wort ( Hypericum perforatum ) ↓Dolutegravir Avoid coadministration with TIVICAY or TIVICAY PD because there are insufficient data to make dosing recommendations. (Dolutegravir label, Drug interactions)

  • Doxepintricyclic antidepressantMajor

    Combining St. John's wort with antidepressants and other serotonergic drugs increases the risk of serotonin syndrome. (NCCIH, St. John's Wort)

  • Drospirenone and ethinyl estradioloral contraceptiveMajor

    St. John's wort can make birth control pills less effective. (NCCIH, St. John's Wort)

  • DuloxetineSNRIMajor

    Combining St. John's wort with antidepressants and other serotonergic drugs increases the risk of serotonin syndrome. (NCCIH, St. John's Wort)

  • EdoxabananticoagulantMajor

    St. John's wort can weaken these medicines by speeding up their breakdown, which can mean organ rejection, clots, or loss of effect. (NCCIH, St. John's Wort)

  • EletriptantriptanMajor

    Combining St. John's wort with antidepressants and other serotonergic drugs increases the risk of serotonin syndrome. (NCCIH, St. John's Wort)

  • Emtricitabine and tenofovirantiretroviralMajor

    St. John's wort can lower blood levels of some HIV medicines enough to cause treatment failure. (NCCIH, St. John's Wort)

  • EscitalopramSSRIMajor

    Combining St. John's wort with antidepressants and other serotonergic drugs increases the risk of serotonin syndrome. (NCCIH, St. John's Wort)

  • EstradiolestrogenMajor

    St. John's wort can make birth control pills less effective. (NCCIH, St. John's Wort)

  • EverolimusimmunosuppressantMajor

    St. John's wort can weaken these medicines by speeding up their breakdown, which can mean organ rejection, clots, or loss of effect. (NCCIH, St. John's Wort)

  • Felodipinedihydropyridine calcium channel blockerMajor

    St. John's wort can weaken these medicines by speeding up their breakdown, which can mean organ rejection, clots, or loss of effect. (NCCIH, St. John's Wort)

  • FentanylopioidMajor

    St. John's wort can weaken these medicines by speeding up their breakdown, which can mean organ rejection, clots, or loss of effect. (NCCIH, St. John's Wort)

  • FlibanserinCNS depressantMajor

    Combining St. John's wort with antidepressants and other serotonergic drugs increases the risk of serotonin syndrome. (NCCIH, St. John's Wort)

  • FluoxetineSSRIMajor

    Combining St. John's wort with antidepressants and other serotonergic drugs increases the risk of serotonin syndrome. (NCCIH, St. John's Wort)

  • FluvoxamineSSRIMajor

    Combining St. John's wort with antidepressants and other serotonergic drugs increases the risk of serotonin syndrome. (NCCIH, St. John's Wort)

  • GranisetronQT-prolonging drugMajor

    Combining St. John's wort with antidepressants and other serotonergic drugs increases the risk of serotonin syndrome. (NCCIH, St. John's Wort)

  • ImatinibCYP3A4 inhibitorMajor

    St. John's wort can weaken these medicines by speeding up their breakdown, which can mean organ rejection, clots, or loss of effect. (NCCIH, St. John's Wort)

  • IsoniazidantibioticMajor

    Combining St. John's wort with antidepressants and other serotonergic drugs increases the risk of serotonin syndrome. (NCCIH, St. John's Wort)

  • IvabradineMajor

    St. John's wort can weaken these medicines by speeding up their breakdown, which can mean organ rejection, clots, or loss of effect. (NCCIH, St. John's Wort)

  • Lansoprazoleproton pump inhibitorMajor

    Intervention: St John's Wort, rifampin : Avoid concomitant use with PREVACID or PREVACID SoluTab. (Lansoprazole label, Drug interactions)

  • LevomilnacipranSNRIMajor

    Combining St. John's wort with antidepressants and other serotonergic drugs increases the risk of serotonin syndrome. (NCCIH, St. John's Wort)

  • LevonorgestrelprogestinMajor

    St. John's wort can make birth control pills less effective. (NCCIH, St. John's Wort)

  • Levonorgestrel and ethinyl estradioloral contraceptiveMajor

    St. John's wort can make birth control pills less effective. (NCCIH, St. John's Wort)

  • LinezolidantibioticMajor

    Combining St. John's wort with antidepressants and other serotonergic drugs increases the risk of serotonin syndrome. (NCCIH, St. John's Wort)

  • Lithiumserotonergic drugMajor

    Combining St. John's wort with antidepressants and other serotonergic drugs increases the risk of serotonin syndrome. (NCCIH, St. John's Wort)

  • LovastatinstatinMajor

    St. John's wort can weaken these medicines by speeding up their breakdown, which can mean organ rejection, clots, or loss of effect. (NCCIH, St. John's Wort)

  • MedroxyprogesteroneprogestinMajor

    St. John's wort can make birth control pills less effective. (NCCIH, St. John's Wort)

  • MegestrolprogestinMajor

    St. John's wort can make birth control pills less effective. (NCCIH, St. John's Wort)

  • MeperidineopioidMajor

    Combining St. John's wort with antidepressants and other serotonergic drugs increases the risk of serotonin syndrome. (NCCIH, St. John's Wort)

  • MethadoneopioidMajor

    St. John's wort can weaken these medicines by speeding up their breakdown, which can mean organ rejection, clots, or loss of effect. (NCCIH, St. John's Wort)

  • MidazolambenzodiazepineMajor

    St. John's wort can weaken these medicines by speeding up their breakdown, which can mean organ rejection, clots, or loss of effect. (NCCIH, St. John's Wort)

  • MirtazapineantidepressantMajor

    Combining St. John's wort with antidepressants and other serotonergic drugs increases the risk of serotonin syndrome. (NCCIH, St. John's Wort)

  • Naltrexone and bupropionopioid antagonistMajor

    Combining St. John's wort with antidepressants and other serotonergic drugs increases the risk of serotonin syndrome. (NCCIH, St. John's Wort)

  • Nifedipinedihydropyridine calcium channel blockerMajor

    St. John's wort can weaken these medicines by speeding up their breakdown, which can mean organ rejection, clots, or loss of effect. (NCCIH, St. John's Wort)

  • Nirmatrelvir and ritonavirantiviralMajor

    John's Wort ( hypericum perforatum ) • History of clinically significant hypersensitivity reactions to the active ingredients (nirmatrelvir or ritonavir) or any other components. (Nirmatrelvir and ritonavir label, Contraindications)

  • NorethindroneprogestinMajor

    St. John's wort can make birth control pills less effective. (NCCIH, St. John's Wort)

  • Norethindrone and ethinyl estradioloral contraceptiveMajor

    St. John's wort can make birth control pills less effective. (NCCIH, St. John's Wort)

  • Norgestimate and ethinyl estradioloral contraceptiveMajor

    St. John's wort can make birth control pills less effective. (NCCIH, St. John's Wort)

  • Nortriptylinetricyclic antidepressantMajor

    Combining St. John's wort with antidepressants and other serotonergic drugs increases the risk of serotonin syndrome. (NCCIH, St. John's Wort)

  • OndansetronQT-prolonging drugMajor

    Combining St. John's wort with antidepressants and other serotonergic drugs increases the risk of serotonin syndrome. (NCCIH, St. John's Wort)

  • OxycodoneopioidMajor

    St. John's wort can weaken these medicines by speeding up their breakdown, which can mean organ rejection, clots, or loss of effect. (NCCIH, St. John's Wort)

  • PalbociclibCYP3A4 inhibitorMajor

    Avoid concomitant use of strong CYP3A inducers (e.g., phenytoin, rifampin, carbamazepine, enzalutamide, and St John's Wort) [see Clinical Pharmacology (12.3) ] . (Palbociclib label, Drug interactions)

  • ParoxetineSSRIMajor

    Combining St. John's wort with antidepressants and other serotonergic drugs increases the risk of serotonin syndrome. (NCCIH, St. John's Wort)

  • PhenelzineMAO inhibitorMajor

    Combining St. John's wort with antidepressants and other serotonergic drugs increases the risk of serotonin syndrome. (NCCIH, St. John's Wort)

  • ProgesteroneprogestinMajor

    St. John's wort can make birth control pills less effective. (NCCIH, St. John's Wort)

  • Prucaloprideserotonergic drugMajor

    Combining St. John's wort with antidepressants and other serotonergic drugs increases the risk of serotonin syndrome. (NCCIH, St. John's Wort)

  • RasagilineMAO inhibitorMajor

    Combining St. John's wort with antidepressants and other serotonergic drugs increases the risk of serotonin syndrome. (NCCIH, St. John's Wort)

  • RitonavirantiretroviralMajor

    John's Wort (hypericum perforatum) NORVIR is contraindicated in patients with known hypersensitivity to ritonavir (e.g., toxic epidermal necrolysis, Stevens-Johnson syndrome) or any of its ingredients ( 4 ) (Ritonavir label, Contraindications)

  • RivaroxabananticoagulantMajor

    St. John's wort can weaken these medicines by speeding up their breakdown, which can mean organ rejection, clots, or loss of effect. (NCCIH, St. John's Wort)

  • RizatriptantriptanMajor

    Combining St. John's wort with antidepressants and other serotonergic drugs increases the risk of serotonin syndrome. (NCCIH, St. John's Wort)

  • SelegilineMAO inhibitorMajor

    Combining St. John's wort with antidepressants and other serotonergic drugs increases the risk of serotonin syndrome. (NCCIH, St. John's Wort)

  • SertralineSSRIMajor

    Combining St. John's wort with antidepressants and other serotonergic drugs increases the risk of serotonin syndrome. (NCCIH, St. John's Wort)

  • SimvastatinstatinMajor

    St. John's wort can weaken these medicines by speeding up their breakdown, which can mean organ rejection, clots, or loss of effect. (NCCIH, St. John's Wort)

  • SirolimusimmunosuppressantMajor

    St. John's wort can weaken these medicines by speeding up their breakdown, which can mean organ rejection, clots, or loss of effect. (NCCIH, St. John's Wort)

  • SolriamfetolCNS stimulantMajor

    Combining St. John's wort with antidepressants and other serotonergic drugs increases the risk of serotonin syndrome. (NCCIH, St. John's Wort)

  • SumatriptantriptanMajor

    Combining St. John's wort with antidepressants and other serotonergic drugs increases the risk of serotonin syndrome. (NCCIH, St. John's Wort)

  • Sumatriptan and naproxentriptanMajor

    Combining St. John's wort with antidepressants and other serotonergic drugs increases the risk of serotonin syndrome. (NCCIH, St. John's Wort)

  • TacrolimusimmunosuppressantMajor

    St. John's wort can weaken these medicines by speeding up their breakdown, which can mean organ rejection, clots, or loss of effect. (NCCIH, St. John's Wort)

  • TapentadolopioidMajor

    Combining St. John's wort with antidepressants and other serotonergic drugs increases the risk of serotonin syndrome. (NCCIH, St. John's Wort)

  • TramadolopioidMajor

    Combining St. John's wort with antidepressants and other serotonergic drugs increases the risk of serotonin syndrome. (NCCIH, St. John's Wort)

  • TranylcypromineMAO inhibitorMajor

    Combining St. John's wort with antidepressants and other serotonergic drugs increases the risk of serotonin syndrome. (NCCIH, St. John's Wort)

  • TrazodoneantidepressantMajor

    Combining St. John's wort with antidepressants and other serotonergic drugs increases the risk of serotonin syndrome. (NCCIH, St. John's Wort)

  • VenlafaxineSNRIMajor

    Combining St. John's wort with antidepressants and other serotonergic drugs increases the risk of serotonin syndrome. (NCCIH, St. John's Wort)

  • Verapamilcalcium channel blockerMajor

    St. John's wort can weaken these medicines by speeding up their breakdown, which can mean organ rejection, clots, or loss of effect. (NCCIH, St. John's Wort)

  • VilazodoneSSRIMajor

    Combining St. John's wort with antidepressants and other serotonergic drugs increases the risk of serotonin syndrome. (NCCIH, St. John's Wort)

  • VortioxetineantidepressantMajor

    Combining St. John's wort with antidepressants and other serotonergic drugs increases the risk of serotonin syndrome. (NCCIH, St. John's Wort)

  • WarfarinanticoagulantMajor

    St. John's wort can weaken these medicines by speeding up their breakdown, which can mean organ rejection, clots, or loss of effect. (NCCIH, St. John's Wort)

  • ZolmitriptantriptanMajor

    Combining St. John's wort with antidepressants and other serotonergic drugs increases the risk of serotonin syndrome. (NCCIH, St. John's Wort)

  • Zolpidemsedative-hypnoticMajor

    St. John's wort can weaken these medicines by speeding up their breakdown, which can mean organ rejection, clots, or loss of effect. (NCCIH, St. John's Wort)

Moderate interactions (2)

  • Elexacaftor, tezacaftor, and ivacaftorModerate

    John's wort ( Hypericum perforatum ) Strong or Moderate CYP3A Inhibitors The dosage of TRIKAFTA should be reduced when used concomitantly with strong CYP3A inhibitors [see Dosage and Administration (2.4) and Warnings and Precautions (5.6) ] . (Elexacaftor, tezacaftor, and ivacaftor label, Drug interactions)

  • TheophyllinemethylxanthineModerate

    John’sWort (Hypericum Perforatum) Decrease in theophylline plasma concentrations. (Theophylline label, Drug interactions)

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Not medical advice. Severity reflects the label's wording, not your circumstances. A "major" flag can be routine under supervision and a "minor" one can matter at high doses. Ask a pharmacist.