Investigation of the effect on photosensitivity following repeated oral dosing of Hypericum extract in 20 healthy male and female volunteers

Photosensitivity of the skin is a known side effect of St. John's Wort (SJW). In an open, phase one clinical trial (GCP) the effect of an ethanolic (60% V/V) SJW extract (Esbericum® capsule) on dermal photosensitivity was evaluated by determination of the minimal erythema dose (MED) before and after 2 weeks of therapy. Each of the volunteers received 3 capsules (60mg SJW dry extract (3.5–6:1)/capsule) twice daily (7.00 a.m./p.m.). At days –2 and 14, solar simulated skin irradiation was performed with a Dermalight® Erythemtester (285–350 nm) to determine and analyse MEDpre and MEDpost (paired t-test, Wilcoxon tes…