Definition
A psychomodulatory substance (PML) is, under the amendment to Act No. 167/1998 Coll., on addictive substances, effective from 1 January 2026, a category comprising substances that have a documented psychotropic effect on the central nervous system but do not meet the criteria for classification as addictive substances within the meaning of Section 2 of the same Act, or as medicinal products under Act No. 378/2007 Coll., on pharmaceuticals.
The PML category was introduced as a legal framework for a group of plant and synthetic compounds whose presence on the market had long fallen outside the existing regulatory regimes. Kratom is one of the first substances on the PML list.
What PML means
Classification of a substance as PML brings, under the law, the following general rules:
- distribution may be carried out only by a person with a licence to handle PML,
- sale to persons under 18 is prohibited (see the age restriction),
- the packaging must contain information on the content of the main active substances,
- advertising aimed at minors is prohibited,
- import, export and transit are subject to a notification obligation to the Czech Ministry of Health.
The specific procedural details (the form of record-keeping, the technical requirements for labelling) are in the implementing decrees.
Difference from addictive substances under Section 2
The key difference lies in the degree of restriction on distribution:
- An addictive substance (Section 2 of Act 167/1998 Coll.) - typically does not pass through the ordinary consumer market. Only pharmacies, research institutions and other entities under separate authorisations may handle the substance. Distribution outside this circle is a criminal offence.
- A psychomodulatory substance (PML) - distribution is possible in the commercial network, but under a licence from the Czech Ministry of Health, with record-keeping and restrictions (age, labelling, advertising).
PML is therefore, by its nature, a moderately strict regime between the general consumer market and the regime for addictive substances.
The list of substances and how it is added to
The list of substances classified as PML is kept by the Czech Ministry of Health. The addition of a new substance takes place:
- on the initiative of the State Institute for Drug Control (SÚKL) or the National Drug Headquarters of the Czech Police,
- after assessment by an expert committee of the Czech Ministry of Health,
- by the issue of an implementing decree or a government regulation.
As of 1 January 2026, the list primarily includes kratom (Mitragyna speciosa) and its main alkaloids. Further substances are under assessment.
Relationship to EU regulation
The PML category is a purely national legal construct. As of 2026, the European Union has no harmonised regulation for the group of substances that the Czech Republic covers with the concept of PML; individual Member States have chosen different approaches (a complete ban, a novel-food regime, no specific regulation). A comparison is described in the article The status of kratom in EU countries.
Frequently asked questions
Why was the PML category introduced?
The explanatory memorandum states that the existing division between "addictive substances" and the general consumer market did not allow for proportionate regulation of a group of substances with a documented psychotropic effect that are not classic narcotics. PML is the answer to this regulatory gap.
Who classifies substances onto the list?
The Czech Ministry of Health, after assessment by an expert committee. Initiatives may be submitted by SÚKL, the National Drug Headquarters of the Czech Police, or other state authorities.
Does it differ from the US Schedule?
Yes. The American Controlled Substances Act has five classes (Schedule I-V), all with a narcotic character. PML is a separate category with no direct equivalent in American law - closer, for example, is the French model of plantes à effets psychotropes.
Can synthetic substances also be placed on the PML list?
Yes. The law does not distinguish between plant and synthetic origin; the decisive factor is the functional criterion of a psychotropic effect without meeting the criteria for an addictive substance.
References
- Sections 2 and 3 of Act No. 167/1998 Coll., on addictive substances, as amended.
- Explanatory memorandum to the amendment of Act No. 167/1998 Coll. (Chamber of Deputies of the Parliament of the Czech Republic, 2025).
- Collection of Laws of the Czech Republic, year 2025.
