I know of several people who use different varieties of Psilocybe mushroom and make a concentrate which they then mix (usually for capsuling) with a thick, inert oil or emulsion. Making psilocybin and psilocin is incredibly difficult, not an easy synthesis at all, more difficult than even LSD-25 so it is unlikely that you would find any synthetics anywhere, and if you did they would be prohibitively expensive!