Neuroendocrine evidence for dopaminergic actions of hypericum extract (LI 160) in healthy volunteers
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Updated: Oct 19, 2026
Assessment of Dopaminergic Homeostasis in Mice by Use of High-performance Liquid Chromatography Analysis and Synaptosomal Dopamine Uptake
Published on: September 21, 2017
1University Department of Psychiatry, Warneford Hospital, Oxford, UK.
Background:
We studied the effect of a single dose of a formulation of a methanolic extract of Hypericum perforatum (HP), also known as St. John's wort, on plasma concentrations of growth hormone (GH), prolactin (PRL), and cortisol (CORT) in 12 healthy male volunteers.
Methods:
Subjects received 9 tablets of the finished product Jarsin 300 and placebo in a double-blind, balanced-order, cross-over design.
Results:
Following HP relative to placebo, there was a significant increase in plasma GH and a significant decrease in plasma PRL. Plasma CORT levels were unchanged.
Conclusions:
Taken together with data from animal experimental studies, the findings suggest that this dose of HP may increase some aspects of brain dopamine function in humans.
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