What cacti grows the fastest? I've never thought about mescaline and cacti because I've always had the idea that it takes years to grow a Peyote that works. Is that true? How about San Pedro or Peruvian torch. Do the need years to become psychoactive?

No they do not however even if they did one can buy cuttings that are already mature. New growth contains alkaloid content. If you got loph cuttings or pups they would have alk content as they have the maturity level of their parent, it is growing from seed that takes a long time. Not to sure how long it takes trich seedlings to have significant levels although it is likely significantly less than Loph. Anyway one should just obtain cuttings if they are interested, as these are from mature specimens.

Some trichocereus clones grow very fast up to a few feet per year. There are many different clones with varying phenotypes. Alkaloid content and growth is very variable.

My T. pachanoi grew to a meter from a foot cutting in about a year. Even the loph buttons he had grafted on pereskiopsis grew in significant difference in the same time frame. very reliable grafting medium, but suspected loss of psychoactivity. They just look really neat.. lol

I wonder the same for achuma and torch

EDIT:: Found this laying around. http://www.thenook.org/a.../pereskiopsis-peyote.htm
The guy apparently grew from a seedling sprouting several pups in T+ 3months

Order a non-predominant cultivator from Sacred Succulents (Relevant? If not please PM me and I'll be happy to edit).