Hypericum: Photosensitivity and St. Johnswort
by Paul Bergner
Medical Herbalism 01-31-95 6(4): 10
St Johnswort (Hypericum perforatum) has long been know to potentially cause sensitivity to sunlight in grazing animals. The extent of the problem in humans has not been clearly defined. Hypericin, a constituent of St Johnswort is believed to be responsible.
annual convention of the
American Association of Naturopathic Physicians
in San Diego in
September, Jo Jenner, ND, or Portland, OR,
reported a case of
hypericum-induced photosensitivity in herself
through an unusual
mechanism. She had sprained an ankle, and
treated it with ultrasound,
including a ultrasound gel containing hypericum.
treatment purportedly drives herbal material in
the gel directly into
the tissues. After the treatment, Jenner worked
outdoors in bright
sunlight, and developed second degree burns,
with blisters, wherever
sunlight fell on the treated surfaces of her
ankle. She had worked in
bright sunlight. Areas covered by her sandal
strap, and at the back of
her ankle where no light fell, were spared. The
burns were extremely
painful, and complete healing took more than a
month. In the ensuing
discussion, Jennifer Brett, ND, of Stratford,
that she had seen frequent photosensitivity
reactions to St Johnswort
in HIV patients that she treated. Recently a New
York clinical trial of
hypericin in HIV-infection had to be stopped
because a large number of
the participants developed photosensitivity.
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