La méthamphétamine est elle présente à l'état naturel?

"S. berlandieri contains a number of diverse alkaloids, the most plentiful of which are N-methylphenethylamine, tyramine, and phenethylamine.[3] The total alkaloid content in dried leaves has been reported to be in the range 0.28-0.66%.[8] In a recent study, researchers identified thirty-one alkaloids in samples of plant foliage, including trace amounts of four amphetamines previously known only from laboratory synthesis: amphetamine, methamphetamine, para-hydroxyamphetamine and para-methoxyamphetamine. Other trace alkaloids include nicotine, and mescaline (found in many cacti but infrequently in other plants).[3] The same group of researchers later reported finding most of the same alkaloids in A. rigidula, a related species also native to the Southwestern U.S.[9] There are no reports in the literature of these findings having been repeated, however, leading to the suggestion that they resulted from cross-contamination or were possibly artifacts of the analytical technique.[10]"

https://en.wikipedia.org/wiki/Senegalia_berlandieri

Attention il s'agit donc de TRACES , et il n'y a eu qu'une seule étude alors il faut agir avec prudence ! 
De plus pourquoi ces traces seraient elles présentes? il pourrait s'agir tout simplement de contamination  (ex: un analyse de mdma de la part d'un usager de morphine a de grande chance de contaminer son produit) ou d'un artefact qui provient de la méthode d'analyse.

Cordialement