A regulator calls the serotonin interaction possible, not established
The UK review classes its interactions with SSRI antidepressants and with triptans, the migraine drugs, as resting on spontaneous case reports. No controlled study has tested either.
What the study found
The serotonin warning is the regulator's weakest word: possible
The UK regulator's review classes St John's Wort's interactions with SSRI antidepressants and with triptans, the migraine drugs, as possible rather than established, resting on spontaneous case reports. No controlled study has put either combination to a test.
The caveat · Shows it happens, not how often
Spontaneous reporting can establish that an interaction happens in practice but never how often, and it skews toward the severe and the newsworthy. The regulator's review closed in 2002, before the work showing that hyperforin content decides how strongly any given preparation induces anything.
What we don't know
Whether St John's Wort taken with serotonin-acting antidepressants or migraine triptans risks serotonin syndrome rests on case reports, which show it can happen but not how often. No controlled study has tested either pairing.