What are Atlantis truffles?

Atlantis truffles are sclerotia: hard, knobbly nuggets of compacted mycelium that the fungus Psilocybe atlantis forms underground as a food reserve. They contain psilocybin, the same compound that makes magic mushrooms psychoactive, and they are eaten fresh.

A fungus from a lawn in Georgia

Psilocybe atlantis was described in 2003 by the Mexican mycologist Gastón Guzmán together with Richard Hanlin and Cathy White, in the journal Mycotaxon. The original collection grew in a patch of moss beside a house in Fulton County, Georgia, on a lot bordering woodland less than fifty metres from a tributary of the Chattahoochee River. The species has only been recorded from Georgia and is closely related to Psilocybe mexicana, the mushroom that Albert Hofmann used in 1958 to isolate psilocybin.

Fulton County is home to the city of Atlanta. The sunken city on some packaging is decoration.

What a sclerotium is

Most people picture a mushroom as the cap and stem above ground. That part is only the fruiting body. The fungus itself is a network of fine threads, the mycelium, that lives in soil or wood. Under some conditions, a few Psilocybe species compact part of that network into dense lumps that can survive drought or cold and later sprout again. Those lumps are sclerotia.

Commercially grown truffles are cultivated in sealed containers on a grain substrate. The growers keep conditions such that the fungus forms sclerotia and no mushrooms. After harvest the truffles are washed, weighed and vacuum packed. They look like small, light brown stones or peeled ginger, with a firm, slightly rubbery texture and a nutty, bitter taste.

Truffles and mushrooms compared

A laboratory study by the Italian National Institute of Health measured commercial truffles and found only psilocybin, at 59 to 168 micrograms per 100 milligrams of fresh material. That is 0.6 to 1.7 milligrams per gram, so a 15 gram pack holds somewhere between 9 and 25 milligrams. The study did not name Atlantis. It does show how much natural variation there is between batches (Pellegrini et al., 2013).

Why truffles are legal in the Netherlands

In 2008 the Dutch government banned fresh psilocybin mushrooms after a series of incidents with tourists. The law names paddenstoelen, mushrooms. Sclerotia are not mushrooms in the botanical sense, so truffles stayed outside the Opium Act; the Supreme Court confirmed in April 2026 that they can be grown and sold freely (Hoge Raad, ECLI:NL:HR:2026:450). Dried truffles are less clear. No court has ruled on them, and the Jellinek classes them as a preparation of psilocybin on List I, the hard drugs list (Jellinek). Keep them fresh.

Outside the Netherlands the picture is much stricter. In Germany psilocybin and the organisms that contain it are controlled under the Narcotics Act, and the United Kingdom has treated psilocybin fungi in any form as Class A since 2005. Taking truffles home from Amsterdam is illegal in most countries, including in your luggage.

Philosopher's stones, and growing your own

"Philosopher's stones" was originally the nickname for the sclerotia of Psilocybe tampanensis, a species first collected in Florida in 1977. Shops now use it loosely for all magic truffles.

Instead of buying a pack, you can grow Atlantis truffles yourself from a grow kit: a sealed tub of colonised substrate that you leave at room temperature for four weeks or longer before harvesting. This is legal in the Netherlands for fresh truffles, and the harvest is as fresh as it gets. Check your local law before ordering a kit abroad.

Next: effects and timeline, or how Atlantis compares with other strains.