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Hypericin/St. John's Wort Info Sheet

May 1996

What Is It Really?

St. John's Wort is a naturally occurring herb which contains a chemical called hypericin. Synthetic forms of hypericin are under investigation as an anti-HIV treatment. The herbal product is available through buyers clubs and some health food stores. The synthetic hypericin is currently only available through clinical trials.

The Theory Behind Taking Hypericin/St. John's Wort

People have been growing St. John's Wort for centuries and herb lore has long attributed curative properties to it. Lately researchers have confirmed that one of the chemicals derived from the plant, hypericin, has potent activity in the test tube against a wide range of viruses including HIV, CMV, and maybe HPV (genital warts). Hypericin interferes with viral budding, that is, when new viruses pop out of an infected cell. Exposure to light makes hypericin even more active.

Hypericin/St. John's Wort Studies in PWAs

One ACTG trial used an intravenous synthetic hypericin that delivered very high but short-lived levels of hypericin to the blood. Exposure to that much hypericin at once caused side effects like painful itching, burning sensations and severe rash, known as photo-toxicity. The short half-life meant that they could not get levels in the blood equal to the levels that had an anti-HIV effect in the test tube. All and all, a lose-lose situation. A new ACTG study has begun to study an oral formula designed to get more consistent levels of the drug in the blood. One positive thing may have come out of the study, though. The hypericin may have caused a spontaneous remission of a bad case of genital warts in one patient. Last year, results were published from a small open label study that followed 18 patients using an injectable hypericin (that we don't carry but other buyer's clubs may) and oral hypericin. Two patients were not evaluable. The researchers reported that of the remaining sixteen patients, fourteen had stable or increased CD4 cell counts, and did not develop opportunistic infections during the course of the study.

Purity of Product

We know next to nothing about the purity, or consistency of the St. John's Wort products that we carry. They are not pharmaceutical grade products, and like many products sold at health food stores, you have only the manufacturer's assurance that they practice good quality control. In every brand of St. John's Wort available, the amount of hypericin is small. HY2 is more potent and more expensive, but we don't know how much active hypericin is really in either product or whether these amounts are consistent. Both products also contain pseudo-hypericin, which also has anti-viral activity in the test tube.


There is no information about how much St. John's Wort one should use. For one thing, we do not know if PWAs can absorb enough hypericin from herbal products to cause the anti-viral effects seen in test tube studies. Secondly, we can't guarantee the dose of hypericin in any of these products. We don't have the slightest clue what the most adequate dose of Yerba Prima or HY2 is in PWAs. We suggest you consult with your doctor in choosing a dose of St. John's Wort. The manufaturers of each product recommend the following doses: Yerba Prima, 1 tablet twice a day (some PWAs on the underground report taking anywhere from 2-16 tablets). HY2, between 2 and 5 tablets a day.

Side Effects and Toxicity

The most common hypericin-related toxicity was first seen in livestock. Cows that grazed on St. John's Wort came down with photo-toxic reactions Ñ severe sores. The PWAs in the synthetic hypericin study had photo-toxic reactions which were very painful, including severe rashes, itching and burning sensations. Exposure to the sun could be debilitating. No studies have ever evaluated the toxicity of the two herbal products that we carry. Some clients using higher doses of either product have reported that they occasionally experienced the rash or burning sensations.

What We Carry

Studies about the pure synthetic hypericin tell us little about the herbal products we carry: Yerba Prima tablets, and Pacifics Biologics' HY2. Yerba Prima comes in bottles of 180 X 250 mg tablets. The manufacturer claims it contains 0.14% hypericin. HY2, made by Pacific BioLogics, Inc., comes in bottles of 150 capsule. Each capsule contains 750 mg of St. John's Wort, of which 2.25 mg is mixed hypericin. There is no information which indicates that the amount of hypericin contained even in the brand with the highest concentration (Pacific Biologics) is any where near the level necessary to inhibit HIV.

Open Clinical Trials

There are no studies of herbal hypericin currently running in the US. However, the ACTG is running a dose-ranging study evaluating the anti-viral activity of a new oral synthetic hypericin at Bellevue/New York University and Beth Israel in Boston. To participate in the study you need to have a CD4 cell count between 50-350 and must not have used any other anti-HIV drug for at least a month. For more information, in New York call Mary Ann Kiernan at (212) 263-6565, in Boston call Sheila Hussey at (617) 735-4103. In Boston, they are also running a small study looking at oral synthetic hypericin's activity against genital warts.

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