S
g flowers)/cup water 1–2 ×/day for 4–6 wk (APA); 2–4 ml liquid flowering tops extract (1:1 in
25% ethanol) 3 ×/day (CAN); 2–4 ml flowering tops tincture (1:10 in 45% ethanol) 3 ×/day (CAN);
1–2 ml flowering tops tincture 3 ×/day (SKY); 1–2.7 mg/day hypericum (MAB); 0.2–1.0 mg total
hypericin (PIP); 500 mg StX (0.2% hypericin) (SKY); 1 (430 mg) capsule (StX with 300 mg
certified potency extract with at least 0.3% hypericin in a synergistic base of St. John’s-Wort powder)
3 ×/day with a large glass of water (NH).
Contraindications, Interactions, and Side Effects (St. John’s-Wort) — Class 2d. May potentiate
MAOIs (AHP). Active ingredients may be photoactive, especially in fair-skinned people. Reichert
takes it even more seriously: Although hypericum is not as strong as synthetic MAOIs, patients
should still avoid the things usually avoided: high tyramine foods (smoked or pickled), alcoholic
beverages, amphetamines, cold and hay fever remedies, narcotics, tryptophan, and tyrosine (I no
longer believe this caveat is desirable). Do not take during pregnancy or intense sun exposure
(Reichert, 1994; WAM). Commission E reports adverse effect of photosensitivity. Other sources
report flowering top permitted for external use only; not to be used before exposure to sunlight
(AEH). Foster (1996) is moderate, suggesting that St. John’s-Wort should not be mixed with
synthetic antidepressants. Because it may inhibit MAO, taking it with SSRIs, such as Prozac, could
cause serious health damage. Although side effects have not been reported in clinical studies, range
animals eating the plant and then standing in bright sunlight have experienced sunburn or blindness
from photosensitization. This treatment option should be discussed with your health care provider
(Foster, 1996). The Herbal PDR state that photodermatosis in animals usually kicks in after high
doses, such as 3000 mg per kg body weight (PHR). CAN cautions that hypericin is phototoxic.
“Mice given 0.2–0.5 mg of the herb were found to develop severe photodynamic effects. Delayed
hypersensitivity or photodermatosis has been documented for St. John’s-wort, following the inges-
tion of a herbal tea made from the leaves” (CAN). ESCOP recommends a limited daily intake of
1 mg total hypericin (QRNM, 1997:292). Because of slight uterine activity in vitro, its use in
pregnancy and lactation is to be avoided (CAN). No contraindications or drug-drug interactions
reported (PIP). A recent Internet message cautions about the potential for serotonin syndrome.
Symptoms include chills, confusion, fever, myoclonus, hyperactive reflexes, myoclonus, speech
difficulties, and sweating. Cannot be mixed with an SSRI. That is likely to produce serotonin
syndrome—severe headache, tachycardia, and diaphoresis—which resembles neuroleptic malignant
syndrome (O’Brien, 1998). Recently found to detoxify all the same drugs that grapefruit potentiates.
It induces cytochrome P3A4 450, which speeds up metabolism of several drugs. Nierenberg et al.,
1999 kindly remind us that, like synthetic antidepressants, this herbal antidepressant may rarely
induce hypomania in manic patients. Poorly designed Loma Linda studies (Ondrizek) suggest that
hypericum may interfere with fertility. But this was based on soaking “skinned human sperm” for
24 hours in hypericum tea as I recall.
Extracts (St. John’s-Wort) — A StX (600 mg wit, 0.24–0.32% hypericin 3 ×/day) produced
erythema in light-sensitive patients (AHP). Leaf extracts enhance mouse immune system against
Bordetella pertussis and Staphylococcus aureus. Novoimanine is most effective against S.
aureus, with water soluble imanine being more effective than imamine or sulphanilamide. Herb
extracts are reportedly more active against Escherichia, Shigella, and Staphylococcus than
decoctions. Catechin and flavonoid containing fractions inhibit the flu virus 83–100% (CAN).
Amentoflavone is antiinflammatory and antiulcerogenic (CAN). Total flavonoid fraction is
analgesic in mice (CAN). Small amounts of hypericin are tonic and tranquilizing in humans
(CAN). Extracts inhibit catechol-o-methyl-transferase at 100 μM, modulate interleukin-6, block
corticotropin-releasing hormone, reduce the availability of serotonin receptors (IC50 = 6.2
μg/ml) and the associated inhibition of resorption of serotonin into the cell, and block MAO-
A and B in vitro and ex vivo, and hypericin raises levels of melatonin, all factors that may
contribute to antidepressant activity. No statistical evidence was shown in the antiinflammatory
activity of the extract and hydrocortisone (QRNM, 1997:292). With rats the IC50 was only 6.2