Kenneth M. Klemow, Andrew Bartlow e Justin Crawford, Herbal Medicine: Biomolecular and Clinical Aspects, 2nd, CRC Press/Taylor & Francis, 2011, ISBN 978-1-4398-0713-2. URL consultato il 24 ottobre 2017.
«All the recent clinical trials mentioned in the literature suggest that Hypericum is more tolerable than synthetic antidepressants as it causes fewer side effects and also shows similar adverse reactions as seen in placebo-controlled groups. This makes SJW an attractive option for treating depression.»