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"Poisonous" does not mean deadly. Some manifestations of toxicity are subtle. The dose, as always, determines if a plant is safe source of nutrients or a toxic hazard.

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BRIEF: Could a tea named Yerba de meite cause a positive drug test?

I am a drug urinalysis coordinator with the Coast Guard. I have a member that is stating the reason why he came up positive for marijuana is that he drinks a tea named Yerba de Meite. Have you heard of this drink and is this possible?


If by Yerba de Meite, the member meant Yerba Mate, the completely legal, widely available, well-known South American tea, then maybe he should change brands or go back to coffee. Yerba Mate is a caffeine-rich infusion made primarily from Ilex paraguayensis, a type of holly that grows in Brazil, Paraguay, Uruguay, etc. It is not beyond the range of possibility that the brand he uses has other herbs in it, hence my not altogether flippant suggestion that he change brands. It is also not beyond the range of possibility that the member is smoking marijuana and blowing some of the smoke your way, so to speak. And, although I know of no compounds in Ilex paraguayensis or mate mixtures without marijuana in them that interfere with THC analysis, who knows, there might be. I think justice might be served best if you were to find out his source of mate, get some from the same source yourself and analyze that material for THC or whatever component the Coast Guard is interested in. Regardless of the results from that investigation, I would also order him to quit using mate, since he now "knows" it interferes with the drug screen and subsequent violations will be on his head. Giving him a second chance may not meet all the macho requirements of zero tolerance, but will cover you in case he is telling the truth and if he is fibbing, he would know he can't get away with faking it again...