Indeed, there is no requirement that these substances be scientifically tested for safety or efficacy, and many have in fact been proven not to be effective for the conditions they are used. Supplements often contain doses and ingredients wildly different than what is indicated on the labels, as this case demonstrates.
The vitamin and herbal supplement industry is a multi-billion dollar business, and lobbied hard to keep their products from being regulated by the FDA. As a result, the FDA can only step in when something goes wrong, after people have been injured or killed by natural herbs. That happened in 2004, when the FDA banned ephedra, an herbal remedy used in traditional Chinese medicine for thousands of years. Millions of consumers took the herb, on the belief that it was natural, safe, and effective-until the supplement was linked to over 100 deaths.
Ironically, Null and his customers would likely not have been poisoned if his products were held to the same standards and regulations that real drugs are subjected to–and which Null and others in the "alt med" industry have long rejected.