An interesting news bit that suggests Ophiocordyceps sinensis products made from wild crafted Yartsa gunbu have an high arsenic concentration. This is only a news report and I hav enot seen the original research.
Definitely an issue that needs some following up.
Highly prized ‘caterpillar fungus’ declared a danger to health by China’s FDA
by Alice Yan - South China Morning Post - Feb. 5, 2016
Products derived from rare ingredient from Tibet found to contain up to 10 times the national limit of arsenic, officials say.
Cordyceps, or caterpillar fungus, one of the most sought-after and expensive ingredients in traditional Chinese medicine, has been deemed a danger to human health by China’s main food and drug regulator, mainland media report. A recent examination by the State Food and Drug Administration showed that products derived from the fungus, such as powders and tablets, contain excessive arsenic, Chinanews.com reports. The national standard limit for the toxic chemical is 1 milligram per kilogram, but the level found in the supplements ranged from 4.4-9.9mg/kg. Consuming the products over a long period increased the risk of the element, a common poison, accumulating in the body, the authority said. Cordyceps are the fruiting bodies formed after fungus parasitizes the larvae of ghost moths found in mountainous regions of Tibet and Nepal. They make expensive gifts, often given to old people, and are believed to strengthen a person’s immunity system and restrain the development of cancer cells.