Both increase serotonin levels and combining them significantly raises the risk of serotonin syndrome.
St. John's Wort inhibits serotonin reuptake while 5-HTP provides more serotonin precursor, creating a double increase.
Do not combine these supplements. Choose one or the other, and consult your doctor before using either with any antidepressant.
Known drug category interactions for these supplements. Especially relevant if you take prescription medications.
Combining St. John's Wort with SSRIs can cause serotonin syndrome, a potentially life-threatening condition.
NEVER combine St. John's Wort with SSRIs, SNRIs, or MAOIs. Wait at least 2 weeks after stopping an SSRI before starting St. John's Wort.
St. John's Wort reduces the effectiveness of hormonal birth control, potentially causing contraceptive failure.
Use a non-hormonal backup contraceptive method while taking St. John's Wort and for one month after stopping.
St. John's Wort significantly reduces warfarin blood levels, potentially causing blood clots.
Do not take St. John's Wort while on warfarin. If already taking both, do not stop St. John's Wort abruptly — consult your doctor.
Combining 5-HTP with SSRIs can cause serotonin syndrome.
NEVER combine 5-HTP with SSRIs, SNRIs, MAOIs, or tramadol without direct medical supervision.