In a randomised trial, 263 patients were split into three groups; the first group were given 350mg of hypericum three times daily, the second group were given 100mg imipramine daily and the third group were given a placebo tablet. The results showed that the hypericum was more effective than the placebo and just as effective as the imipramine and with less side effects. Though the dose of hypericum used in this trial was higher than most trials, it proved consistently effective over the eight-week study period and the patients taking the St John's wort experienced fewer side effects than those given the conventional drug.

In spite of the benefits of St John's wort for people suffering from mild depression, a number of side effects are associated with this herbal remedy - particularly when taken alongside drug medications - and it should therefore be used under the supervision of a health professional.