St. John's Wort and SSRI antidepressant: interaction, severity and spacing
St. John's Wort and SSRI antidepressant interact because st. John's Wort inhibits serotonin reuptake and adds to an SSRI's effect, which risks serotonin syndrome — agitation, tremor, hyperthermia, and in severe cases seizures. Take them with care. Severe risk.
The interaction in detail
| Pair | St. John's Wort and SSRI antidepressant |
|---|---|
| Type | Nutrient–drug interaction |
| Severity | Severe |
| Required spacing | None specified |
| Onset | At the time of dosing |
Mechanism
St. John's Wort inhibits serotonin reuptake and adds to an SSRI's effect, which risks serotonin syndrome — agitation, tremor, hyperthermia, and in severe cases seizures.
What to do
Do not combine. If you want to switch, taper the SSRI under supervision before starting St. John’s Wort.
How to fit both into one day
Take with food to reduce GI upset. It is a potent enzyme inducer with a long list of interactions — treat it as a medication, not a herb.
Putting St. John's Wort in the morning and SSRI antidepressant in the evening satisfies the 0-hour separation without disrupting either one's absorption window.