While St. John's wort oil has traditionally been applied to the skin for wounds, burns, dermatitis and inflammation, topical use is just beginning to be studied. Because hypericum is photo-active, large amounts taken orally cause photosensitivity. German researchers recently determined that topical use of St. John's wort oil is unlikely to cause a severe skin reaction. However, applying St. John's wort oil topically may cause a rash in people with extremely sensitive or diseased skin or those who have had excessive sun exposure.¹

German researchers recently explored why St. John's wort oil effectively treats inflammatory skin disorders. They discovered that it inhibits the immune cells called T lymphocytes, which in turn produce inflammatory cytokines.²

Marilyn Sterling

References

1. Schempp CM.
Effect of topical application of Hypericum perforatum extract (St. John's wort) on skin sensitivity to solar simulated radiation.
Photodermatol Photoimmunol Photomed 2000 Jun;16(3):125-8.

2. Schempp CM.
Topical application of St John's wort (Hypericum perforatum L.) and of its metabolite hyperforin inhibits the allostimulatory capacity of epidermal cells.
Br J Dermatol 2000 May;142(5):979-84.