There is one published report of a woman collapsing after taking venlafaxine in combination with the Chinese herbal remedy sour date nut (Ziziphus jujube),¹ although she tolerated venlafaxine by itself without side effects. People taking venlafaxine should not take sour date nut.

Venlafaxine, a potent serotonin reuptake inhibitor, has been associated with several cases of serotonin syndrome.^{2 , 3 , 4 , 5} 5-HTP and L-tryptophan are converted to serotonin in the brain, and taking them with venlafaxine may increase venlafaxine-induced side effects. While no interactions with venlafaxine and 5-HTP or L-tryptophan have been reported, until more is known, people taking venlafaxine are cautioned to avoid 5-HTP or L-tryptophan.

Venlafaxine, a potent serotonin reuptake inhibitor, has been associated with several cases of serotonin syndrome.^{6 , 7 , 8 , 9} 5-HTP and L-tryptophan are converted to serotonin in the brain, and taking them with venlafaxine may increase venlafaxine-induced side effects. While no interactions with venlafaxine and 5-HTP or L-tryptophan have been reported, until more is known, people taking venlafaxine are cautioned to avoid 5-HTP or L-tryptophan.

Although there have been no interactions reported in the medical literature, it is best to avoid using venlafaxine with St. John’s wort unless you are under the supervision of a qualified healthcare professional.

One case was reported of a 79-year-old woman with depression treated with venlafaxine who experienced hyponatremia (abnormally low blood levels of sodium).¹⁰ It remains unclear whether this interaction has any but rare ramifications.