And one sample provided a 50 percent overdose. Similar results were obtained when the Los Angeles Times sent 10 leading brands of St. John's Wort to an independent lab. It found three products had less than half the potency on the label and seven out of ten failed to meet the standard test of 90 percent of label strength. The sample from Rexall Sundown, a major manufacturer, had only about 20 percent of the labeled potency, the newspaper reported. In addition, scientists do not agree about what particular agent in St. John's Wort extract should be measured.
Most companies measure a chemical ingredient called hypericin.
However, new published scientific findings now suggest that instead, the active agent might be something else, hyperforin. The problem can be much worse that just getting gypped. Certain babies with an inherited genetic defect will not develop proper muscle strength unless they get the right dose of the amino acid l-carnitine, a dietary supplement. As a safety check, Meyers' organization for rare diseases asked a Duke University laboratory to check out 12 samples of the drug. With a baby's healthy development at stake, a substandard product becomes just as dangerous as highly toxic contaminant.