[retrac]

> I’ve read that people are working on deriving psilocybin from yeast but haven’t heard much as of late.

They were successful. A team at the Technical University of Denmark inserted the genes to synthesize psilocybin into Saccharomyces cerevisiae (brewer's yeast) [1] and they had excellent yields:

> a final production strain producing 627 ± 140 mg/L of psilocybin and 580 ± 276 mg/L of the dephosphorylated degradation product psilocin in triplicate controlled fed-batch fermentations

It's likely the means it will be produced commercially if it becomes a widely-approved drug. Not sure the average person will be able to get their hands on that strain easily anytime soon though. I imagine it'll be guarded as a trade secret as strictly as those modified E. coli that pump out human insulin.

[1] https://www.sciencedirect.com/science/article/pii/S109671761...