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June 24, 2024

Thailand Regulatory Change Paves Way for Psilocybin and Opiate Clinical Trials

Thailand’s Minister of Public Health recently promulgated the Ministerial Notification Re: Category 5 Narcotics Which Are Not Cannabis or Hemp Extract and Whose Consumption is Permitted for Treatment of Disease or for Research Purposes (2024). The notification took effect on April 23, 2024.

The substances whose regulatory controls are affected by this new notification are psilocybin mushroom (Psilocybe cubensis (Earle) Singer), opium poppy (Papaver somniferum L. and Papaver bracteatum Lindl.), and other plants in these genera from which opium, opium alkaloids, psilocybin, or psilocin may be derived. As a result of this notification, these substances are now classified as category 5 narcotics that can be applied in medical treatment. Without the implementation of this notification, patients could not access newly developed medicines containing these substances, as Thailand’s Narcotic Code prohibits the possession and use of category 5 narcotics.

Nonetheless, this does not mean that psilocybin mushrooms and opium can be used without any conditions. There is still a long process to go through before these substances can be used in medical treatment or clinical studies. Under the new notification, the FDA must first approve any medicinal drug formulation containing any of the above substances, and subsequently, the production must be approved for medical use or research purposes. The importation of medicinal drug formulations containing psilocybin mushrooms or opium is not allowed.

This seemingly small regulatory change addresses the previous legal obstacle to the research and development of such medicines. According to the previous regulation, a physician or researcher could apply to the Thai FDA for a license to produce or possess medicines containing the aforementioned narcotics. However, production and consumption are considered different activities, and consuming a narcotic-containing medicine, even if it was produced under a valid license, is prohibited by the Narcotics Code and is punishable by imprisonment, a fine, or both. Therefore, subjects in a clinical trial would not have been able to consume such medicines without falling afoul of the Narcotics Code.

In this new notification, the minister invoked his authority under sections 58 and 104 of the Narcotics Code to permit consumption, thereby exempting the patients in trials from legal liability if the narcotic-containing formulation has been produced under a valid license. Accordingly, clinical trials for such formulations are now legal in Thailand.

According to public databases, there is no report of such a clinical trial having been conducted in Thailand. Under the new regulatory landscape, however, Thailand is now ready to host this type of clinical trial—examples include studies of opium’s painkilling effects [1,2], psilocybin’s antidepressant properties [3], psilocybin’s therapeutic potential for alcohol addiction [4,5] and tobacco addiction [4,6], and psilocybin’s potential use as a tranquilizer and for toothaches [7,8].

Apart from the new drug development and access to drugs derived from psilocybin mushrooms and opium enabled by this notification, Thailand’s Department of Intellectual Property will likely react to this change by no longer viewing medical use of these narcotics as contrary to public order or morality, thereby making inventions containing these formulations patentable.

Because it clears legal obstacles impeding pharmaceutical research into derivatives of psilocybin mushroom and opium, this notification is an important step forward for the development of drugs that use category 5 narcotics in Thailand.



[1] Vadhel A, Bashir S, et al. Opium alkaloids, biosynthesis, pharmacology and association with cancer occurrence. Open Biol. 2023 May; 13(5): 220355.

[2] Kaye A, Patel N, Bueno FR, et al. 2014. Effect of opiates, anesthetic techniques, and other perioperative factors on surgical cancer patients. Ochsner J. 2014 Summer; 14(2): 216-28.

[3] Carhart-Harris R, Giribaldi B, Rosalind Watts, et al. Trial of Psilocybin versus Escitalopram for Depression. N Eng J Med. 2021;384(15):1402-11.

[4] Ziff S, Stern B, Lewis G, et al. Analysis of Psilocybin-Assisted Therapy in Medicine: A Narrative Review. Cureus. 2022; 14(2):e21944.

[5] Bogenschutz MP, Forcehimes AA, Pommy JA, et al. Psilocybin-assisted treatment for alcohol dependence: a proof-of-concept study. J Psychopharmacol. 2015;29:289–99.

[6] Johnson MW, Garcia-Romeu A, Cosimano MP, et al. Pilot study of the 5-HT2AR agonist psilocybin in the treatment of tobacco addiction. J Psychopharmacol. 2014;28:983–92.

[7] Butnariu M, Quispe C, Herrera-Bravo J, et al. Papaver Plants: Current Insights on Phytochemical and Nutritional Composition Along with Biotechnological Applications. Oxid Med Cell Longev. 2022;2022:2041769.

[8] Pieroni A., Quave C. L. Traditional pharmacopoeias and medicines among Albanians and Italians in southern Italy: a comparison. J Ethnopharmacol. 2005;101:258–70.

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