# Roquefort mould (Penicillium roqueforti)

**Penicillium roqueforti**

**Known today as.** The blue mould of blue cheeses.

Kind: Fungus

## What was it used for?

Ripens Roquefort in the caves of Mount Combalou.

## What does modern science say?

Safe to eat in cheese; a relative of the penicillin moulds.

## Pharmacognosy and toxicology

- **roquefortine C**: a neurotoxic alkaloid, at low levels
- **PR toxin**: unstable in cheese
- **mycophenolic acid**: an immunosuppressant, in traces
- **andrastins**: 

**Mechanism.** The mould makes several mycotoxins in culture, and the cheese contains traces of roquefortine C and mycophenolic acid, which risk assessments have found far below any harmful dose; the lipases and proteases of the mould make the cheese. Mycophenolic acid from the related *P. brevicompactum* is the transplant drug mycophenolate; it inhibits IMPDH, the enzyme lymphocytes need to make guanine nucleotides.

**Dose.** A food; the mycotoxins in cheese are below the levels of concern.

**Standing.** A food; the fungus is not on the European Union’s qualified-presumption-of-safety list, which excludes filamentous fungi, though EFSA has found no evidence that the cheese harms health.

## What lore surrounds it?

In 1411 Charles VI of France granted the people of Roquefort-sur-Soulzon the sole right to ripen the cheese in their caves.

## Sources

- The charter of Charles VI for Roquefort-sur-Soulzon (1411).
- Fontaine, K., et al. (2015). “Occurrence of roquefortine C, mycophenolic acid and aflatoxin M1 mycotoxins in blue-veined cheeses.” *Food Control* 47.

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*Roquefort mould.* In *Materia Medica*, edited by B. C. P. Statema. Version 1, revised 2026-10-01. The Thinking Press. https://thethinkingpress.org/materia-medica/roquefort-mould

Historical description, not medical advice.