Supplement stacks / St Johns Wort + Tacrolimus
Can You Take St Johns Wort with Tacrolimus?
St Johns Wort and Tacrolimus: one interaction flagged, scored 3/10 (high risk). The count and score come from an AI-written analysis checked against our interaction rules, which can only make it stricter. Not medical advice.
Safety at a glance
This score comes from an AI-written analysis of the pair. Our interaction rules check it and can only make it stricter, never milder. Informational only: it can't account for your medications, conditions, or genetics.
What the AI-written analysis says
St. John's Wort is known to interact with tacrolimus, potentially reducing its effectiveness by inducing cytochrome P450 enzymes. This could lead to inadequate immunosuppression, increasing the risk of transplant rejection. Caution is advised, and consultation with a healthcare provider is essential before combining these substances.
Tacrolimus is a prescription medication. This page describes publicly documented interactions — it can't see your dose, your other prescriptions, or your labs. Discuss any supplement with the prescriber or pharmacist who manages this medication before combining.
Known interactions
St. John's Wort may decrease the plasma concentration of tacrolimus, leading to reduced immunosuppressive effects.
St. John's Wort
From the AI-written analysis.
Generally considered safe for mild depression but can interact with many medications.
Typical dosage: 300-900 mg daily, divided into doses.
- Gastrointestinal upset
- Fatigue
- Allergic skin reactions
- Consult healthcare provider before use, especially with tacrolimus.
- May cause photosensitivity.
Tacrolimus
From the AI-written analysis.
Effective immunosuppressant but requires careful monitoring of blood levels.
Typical dosage: As prescribed or as directed on the label
- Kidney toxicity
- Hypertension
- Increased risk of infections
- Monitor kidney function and blood pressure regularly.
- Avoid grapefruit juice.
Also commonly mentioned
These come up in questions about this combination. They are not part of the pair above. From the AI-written analysis.
Omega-3 Fatty Acids
Generally safe; may support cardiovascular health and reduce inflammation.
Typical dosage: 1000-3000 mg daily.
- Fishy aftertaste
- Gastrointestinal discomfort
- Consult healthcare provider if on anticoagulants.
- Monitor for bleeding risk.
Vitamin D3
Essential for bone health; generally safe in recommended doses.
Typical dosage: 600-2000 IU daily, depending on blood levels.
- Nausea
- Constipation
- Fatigue
- Monitor blood levels to avoid toxicity.
- Consult healthcare provider for dosage adjustments.
Magnesium
Important for many bodily functions; generally safe but can cause diarrhea in high doses.
Typical dosage: 310-420 mg daily, depending on age and sex.
- Diarrhea
- Nausea
- Abdominal cramping
- Consult healthcare provider if on diuretics or heart medications.
- Monitor for interactions.
Timing
No timing arrangement makes this combination safe — see the warnings above.
Watch out for
- St. Johns Wort strongly induces the liver enzyme (CYP3A4) and gut transporter (P-glycoprotein) that clear tacrolimus, cyclosporine, sirolimus, and everolimus. Published cases document blood levels falling below the therapeutic range with acute organ-transplant rejection as the result. This combination is widely listed as one to avoid entirely — contact the transplant team or prescriber before any St. Johns Wort use, and tell them right away if the two have already been combined so levels can be checked.
- Avoid taking St. John's Wort with tacrolimus; consult healthcare provider for alternatives.
Frequently asked questions
Can you take St Johns Wort and Tacrolimus together?
St Johns Wort and Tacrolimus: one interaction flagged, scored 3/10 (high risk). The count and score come from an AI-written analysis checked against our interaction rules, which can only make it stricter. Not medical advice.
What score does the St Johns Wort and Tacrolimus combination get?
The St Johns Wort and Tacrolimus combination is scored 3/10 (high risk). The score comes from an AI-written analysis checked against our interaction rules, which can only make it stricter. Not medical advice. Always confirm with a healthcare professional.
When should you take St Johns Wort and Tacrolimus?
No timing arrangement makes this combination safe — see the warnings above.
What should you watch out for when combining St Johns Wort and Tacrolimus?
St. Johns Wort strongly induces the liver enzyme (CYP3A4) and gut transporter (P-glycoprotein) that clear tacrolimus, cyclosporine, sirolimus, and everolimus. Published cases document blood levels falling below the therapeutic range with acute organ-transplant rejection as the result. This combination is widely listed as one to avoid entirely — contact the transplant team or prescriber before any St. Johns Wort use, and tell them right away if the two have already been combined so levels can be checked. Avoid taking St. John's Wort with tacrolimus; consult healthcare provider for alternatives.
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Not medical advice
AI-written analysis generated August 11, 2026, checked by our interaction rules · How our analysis works