Why Do Magic Mushrooms Turn Blue? 

Like all other psychedelics, the active compounds in mushrooms are listed as Schedule 1 narcotics in the DEA’s list of controlled substances. Although both psilocybin and psilocin are listed, it’s worth noting that psilocybin is the real active compound in these mushrooms. To feel the effects of the psilocybin, our bodies convert it to psilocin, which also exists in trace amounts in shrooms.  

There are some loopholes when it comes to the legality of mushroom related products, such as the spores used to grow them. Those are federally legal because only the fruiting bodies contain psilocybin, the spores do not. Interestingly, mushrooms are also not scheduled in the Single Convention on Narcotic Drugs, nor on the Convention of Psychotropic Substances. This was confirmed in 2001 when the INCB’s Secretary of the Board made the following statement to the Dutch Ministry of Health:  

“As a matter of international law, no plants (natural material) containing psilocine (psilocin) and psilocybin are at present controlled under the Convention on Psychotropic Substances of 1971. Consequently, preparations made of these plants are not under international control and, therefore, not subject of the articles of the 1971 Convention.” 

The connection between psilocybin and bluing  

One of the most notable physical characteristics of psilocybin mushrooms is the blue hue they get when they get cut or bruised in some way. Aside from being indicative of the mushroom containing psilocybin, for decades mycologists struggled to figure out the root cause of the bluing. In 1967, a research team from Ithaca, New York, had a minor breakthrough when they observed the same bluing reaction in rat brain cells treated with psilocin. They claimed that oxidation of the compound is what caused the reaction.  

Again, psilocin is a minor compound in mushrooms. It’s an unstable molecule that breaks down very quickly, whereas psilocybin is more stable and resilient. Researchers suspected that the compounds vulnerability to the elements was the reason behind the color change, and in 2019, a German pharmaceutical microbiologist and his colleagues were able to prove it.  

According to Hoffmeister, picking, cutting, or damaging the mushrooms in even the slightest way can trigger a chemical reaction that activates two different enzymes in the mushroom, PsiP and PsiL. When a mushroom is mishandled, the PsiP enzyme converts psilocybin to psilocin within the mushroom, similar to how the enzymes in the human liver do. Shortly after, the second enzyme, PsiL oxidizes the psilocin, causing it to become unstable and convert into inactive compounds.  

A summary of this study published by Nature explains that “this action forces individual psilocin molecules to fuse into pairs, trios, and larger groupings; and these psilocin conglomerates appear blue to the human eye because the new chemical structures reflect blue light.”