The Claim
St. John’s wort induces cytochrome P450 3A4 and P-glycoprotein, resulting in significantly reduced plasma concentrations of cyclosporine, oral contraceptives, and immunosuppressants, leading to therapeutic failure.
What the research says
Supports is higher
Support is ahead, but a single strong opposing study can change this.
These are independent scores, not a percentage. Higher-grade studies count more, so a single strong opposing study can outweigh several weaker ones.
St. John’s wort increases the activity of liver enzymes that break down certain drugs, causing lower levels of those drugs in the blood and reducing their effectiveness.
See the scientific wording
St. John’s wort induces cytochrome P450 3A4 and P-glycoprotein, leading to significantly reduced plasma concentrations of drugs such as cyclosporine, oral contraceptives, and immunosuppressants, which may result in therapeutic failure.
St. John’s wort triggers a cellular switch that tells the liver and intestines to make more enzymes and pumps that break down and push out certain drugs, so the drugs leave the body too fast and don’t work.
What the research says
1 studyStudy: Synergy, Additive Effects, and Antagonism of Drugs with Plant Bioactive Compounds
This study shows that natural plant substances, like those in St. John’s wort, can make your body break down certain medicines too fast, so they don’t work as well—like when birth control or transplant drugs stop being effective.
Score breakdown, mechanism chain, raw evidence, ideal studies needed & 1 supporting studies
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.