ImmuneXL Toxicity

Pacific Yew should not be confused with botanically similar species, T. baccata (English yew) and T. cusipidata (Japanese yew), that are recognized as toxic. Taxus brevifolia is not poisonous it is a source of the compound taxol. There are no documented instances of poisoning in humans or animals.

Do to an idiosyncrasy of nature, Taxus brevifolia is lacking in harmful amounts of poisonous alkaloids as documented by V.E. Tyler, Jr. (1960)
"Note On the Occurrence of Taxine in Taxus brevifolia". Journal Of the American Pharmaceutical Association Scientific Edition, Vol. 49, No. 10, pages 683-684.
Taxine yield from fresh needles of Taxus brevifolia, analyzed by Tyler, showed .00077% of fresh weight , and "cyanogenetic glycosides of this type were found to be absent in this alkaloid-poor species".

In June of 1999 Product Safety Labs in Chicago, Ill conducted a 14 day Product Safety Study on rats. 

A. Purpose - to provide information on health hazards likely to arise from exposure to Taxus brevifolia.

B. Procedure - Each animal received 5,000 mg/kg of test substance, as 25% ww suspension in distilled water by intubation. The animals were observed for mortality, signs of gross toxicity and behavioral changes at least once daily for 14 days. Body weights were recorded prior to initiation and at termination.

C. Results- All animals survived, gained weight and appeared active and healthy. There were no signs of gross toxicity, adverse pharmacologic effects or abnormal behavior.