St. John's wort has no effect on pain in polyneuropathy.

The aim of this study was to test if St. John's wort would relieve painful polyneuropathy. The study design was randomized, double-blind, placebo-controlled and cross-over. 54 patients (aged 30–82 yrs) with polyneuropathy were assigned to one of the two treatment sequences. During the two treatment periods of 5 weeks duration, patients rated constant pain, lancinating pain paroxysms, touch-evoked pain and pain on pressure by use of 0–10 point numeric rating scales. 47 patients completed the study. There was a trend of lower total pain score on St. John's wort than on placebo. None of the individual pain ratings were significantly changed by St. John's wort as compared to placebo. Complete, good or moderate pain relief was experienced by 9 patients with St. John's wort and 2 with placebo. In conclusion, St. John's wort has no significant effect on pain in polyneuropathy. (PsycINFO Database Record (c) 2016 APA, all rights reserved)