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What is the equivalent of 30 mg pure psilocybin
in dry w
Q: What is the equivalent of 30 mg pure psilocybin
in dry weight of Psilocybe cubensis mushrooms?

A: This question was answered in relationship to the research by the Griffiths group at Johns Hopkins administering psilocybin to humans. See Psilocybin, Science, and Sacrament.

Psilocybin is converted after ingestion into psilocin, the chemical active in the brain. Most Psilocybe mushrooms contain a mix of psilocybin, psilocin, and baeocystin. While published data about the psilocybin/psilocin content of mushroom species is somewhat sparse, estimates are that normally potency Psilocybe cubensis (the most common psychoactive mushroom available in the United States) contain around 0.5–1.0% total psilocybin + psilocin, by dry weight.

The Griffiths study administered oral psilocybin at 30 mg per 70 kg body weight. This is 0.43 mg/kg or 0.20 mg/lb. For someone weighing 70 kg (154 lbs), this is the approximate equivalent of 4–6 dry grams of Psilocybe cubensis mushrooms. Potency in wild species can vary by up to 1000%, but in commonly available dried mushrooms this variation is likely closer to ±50%. Very strong P. cubensis may contain 30 mg psilocybin in 2.5 dry grams and weak mushrooms may only contain 30 mg in 8 grams.

  1. Trout K. Some Simple Tryptamines. Mydriatic Productions. 2002. pg 73–74.
  2. Gartz J. “Extraction and analysis of indole derivatives from fungal biomass.” Journal of Basic Microbiology. 1994;34 :17–22

Asked By : Anonymous
Answered By : earth
Published Date : 11 / 1 / 2006
Last Edited Date : 10 / 15 / 2011
Question ID : 3173

Categories: [ Dosage ]

Ask Erowid v1.7 - Jul, 2005

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