Is McKennaii legal? Mushrooms and grow kits by country

Table 1. Status of the mushrooms and of grow kits, by country.

Netherlands

Mushrooms that naturally contain psilocin or psilocybin are on List II of the Opium Act, which names the species concerned, Psilocybe cubensis among them (Opium Act¹). The decree that added them took effect on 1 December 2008 (Staatsblad 2008, 486²). According to the Trimbos Institute, dried psilocybin mushrooms were already prohibited from 2002; the 2008 decree added fresh ones (Trimbos, drugsinfo.nl³).

Sources differ on how dried mushrooms are classified today. The explanatory note to the 2008 decree and the Trimbos Institute place both fresh and processed mushrooms on List II; the Jellinek writes that dried mushrooms fall under List I (Jellinek⁴). Either way they are illegal.

Grow kits are legal to sell. The Trimbos Institute explains that you are not buying mushrooms when you buy a kit, and that the mushrooms become illegal as soon as they appear above the surface. For a McKennaii kit this means: buying it is legal, letting it fruit is not.

The Public Prosecution Service regards up to 5 grams of fresh or 0.5 grams of dried mushrooms as a quantity for personal use and in principle does not prosecute possession up to that amount (OM, Opium Act guideline⁵). That is a prosecution policy; it does not make possession legal.

Magic truffles, the sclerotia of some Psilocybe species, are not mushrooms in the legal sense and remain on sale; the Supreme Court confirmed this in April 2026 (Hoge Raad, ECLI:NL:HR:2026:450⁶). P. cubensis kits produce mushrooms, not truffles, so that exception does not cover McKennaii.

United Kingdom

Section 21 of the Drugs Act 2005 placed any fungus that contains psilocin or an ester of psilocin in Class A of the Misuse of Drugs Act 1971, from 18 July 2005 (Drugs Act 2005, s. 21⁷). The Home Office's explanatory memorandum states that importing, exporting, producing, supplying or possessing such mushrooms is an offence "whatever form they are in, whether prepared or fresh" (explanatory memorandum⁸).

We found no statute or official guidance that addresses spores or colonised kits directly. A kit that produces mushrooms produces a Class A drug, and producing one is an offence.

Germany

Psilocin and psilocybin are listed in Annex I of the Narcotics Act (BtMG), the category of substances that may not be traded or prescribed (BtMG, Annex I⁹). The annex also covers organisms and parts of organisms that contain them, and biological material suitable for reproducing them, when misuse for intoxication is intended. Section 2 of the act includes fungi in its definition of such material (BtMG, section 2¹⁰). Spores and colonised kits sold to grow psilocybin mushrooms fall under that wording.

United States

Psilocybin and psilocyn are Schedule I hallucinogens under federal law (21 CFR 1308.11¹¹). Spores contain no psilocybin; a laboratory study of P. cubensis found no tryptamines in them (Gotvaldová et al., 2021¹²). In a letter of January 2024, reported in legal press, the Drug Enforcement Administration stated that spores without psilocybin or psilocin are not federally controlled, and that the material becomes controlled once it contains those substances, for example after germination. A colonised McKennaii kit is past that point.

State law varies. California's Health and Safety Code makes it an offence to cultivate spores or mycelium capable of producing such mushrooms with the intent to produce psilocybin or psilocyn (section 11390). Several states and cities have changed their own rules on mushrooms in recent years; those changes do not alter federal law.

Crossing borders

Dutch shops ship kits abroad, but the law that applies is the law of the country where the kit is delivered and grown, including its import rules. Taking mushrooms out of the Netherlands is illegal under Dutch law, and bringing them into another country is illegal almost everywhere. The Trimbos Institute notes that magic mushrooms are illegal in nearly all other countries.

Safety information is in effects and safety; the kit itself is described in growing from a kit.