This editorial describes the systemic shifts in Thailand’s cannabis policy from medical legalisation since 2019. In 2019, 31 177 Thai people registered for medical cannabis use [1] and new unapproved/unlicensed medicinal cannabis oil formulations were used under a special access scheme. A commercial non-medical market rapidly emerged in 2022, followed by policy reversal in June 2025 that allowed only the sale of cannabis under a prescription from a licensed practitioner (Table 1).

Since 2022, there has been a rapid emergence of a substantial commercialised non-medical cannabis market. This includes 18 433 licensed cannabis dispensaries nation-wide in 2025 [8], with high density observed in Bangkok and tourist areas, where more than three shops were located within 100 to 200 m distance [7]. In 2025, Thai cannabis policy shifted away from permitting the high-density commercial retail landscape because it was associated with an increased prevalence of cannabis use and unauthorized sales [5, 9]. Annual surveys in 2019 to 2022 showed that the prevalence of cannabis use in the past year had increased from 2.2% in 2019 to 4.2% in 2021 and 25% in 2022 [4]. Participants with at least one cannabis outlet within a 400-m radius had a 2.8 times higher odds of using cannabis compared to those with no cannabis outlets [9].

Under the 2025 framework, legal access is restricted to use for medical, research and traditional health purposes and requires the prescription of a standardised medical cannabis product by a licensed practitioner [10]. Cannabis is now to be integrated into formal healthcare pathways under the 2025 to 2026 framework and its use limited to the treatment of specific medical conditions such as epilepsy, spasticity, palliative care in cancer and chronic pain, where treatment has been reported to improve some patient outcomes [11, 12]. The 2025 reversal to medical cannabis policy has not fully reverted to the 2019 medical cannabis policy because the cannabis plant remains delisted from the narcotic list since the year 2022. In 2025, cannabis production and sales for commercial purposes have been re-regulated for medical use and research only. Nevertheless, non-medical use and possession of cannabis flower, as well as home cultivation remains legal since 2022.

This new policy intends to convert former non-medical dispensaries into registered medical clinics and will require qualified practitioners to control all prescriptions. Ministry of Public Health (MOPH) officials made public communications to dispensaries to prepare for the change by giving 3 years notice of the change. It also requires the standardisation of medical cannabis products according to Good Agricultural and Collection Practices (GACP) for all domestic cannabis cultivation. This policy aims to replace high-volume sales of cannabis for non-medical use with the medically supervised use of medicinal products, while strictly prohibiting public consumption and advertising to protect adolescents and the public. A concern from a commercial perspective is that many dispensaries may not generate sufficient revenue after the policy change and may continue to illicitly sell cannabis for non-medical use. The extent of adherence to this policy change is accordingly a critical factor that will warrant robust evaluation. Access to medical cannabis should only be provided when supported by efficacy and safety, and increasing levels of access—which may be promoted by commercial interests—may provide limited benefit to patients and increased risk of harm [13]. For example, psychiatric disorders are among the most common indications for medical cannabis use, yet efficacy and safety data indicate that this this is rarely justified [14].

Policy research can play an important role in assessing the long-term outcomes of these changes by collecting systematic data to address the data gaps revealed during adult legalisation [4, 15]. Researchers can assist policymakers to design more effective regulations to minimize community-level benefits and harms by collecting evidence on commercial sales, policy adherence, patterns of cannabis use and their links with specific medical indications, possible therapeutic benefits, adverse events, cannabis use disorders, psychotic disorders and other health impacts [5, 9].

The research community can also play an important role in formalising traditional Thai medicine’s place within the current regulatory system. Thai traditional use of cannabis has been allowed since 1479 (B.E. 2202) under King Narai The Great of Ayutthaya Kingdom. The Department of Thai Traditional and Alternative Medicine MOPH currently approves oral forms of 16 Thai ancient cannabis formulations (mixed with other Thai herbs) and cannabis oil formulae for a variety of symptoms such as nausea, fatigue, insomnia, pain, anxiety, stress, skin lesion, haemorrhoids, myalgia, numbness and poor appetite. Forms or formulations of cannabis sales allowed for medical cannabis use are not indicated in the 2025 policy change. According to qualitative data, ‘unlicensed’/‘unapproved’ or traditional providers frequently have distinct perspectives on cannabis application that require scientific confirmation to ensure patient safety [5]. By conducting randomised clinical trials, the research community can assess the efficacy, safety and cost effectiveness of traditional Thai medical cannabis use and provide a robust, evidence-based foundation for clinical practice [11, 16].

Current surveillance efforts in Thailand track the annual prevalence of non-medical and medical cannabis use in the general population in all regions of Thailand by using a cross-sectional survey [4]. Notably absent are monitoring systems that would assess the use of specific cannabis products (i.e. types, Δ-9-tetrahydrocannabinol and cannabidiol concentrations and retail prices) and cannabis-related consequences such as traffic and workplace accidents, frequency of daily use, psychiatric disorders and healthcare admissions including cannabis use disorders and psychotic disorders and broader public health outcomes. These gaps in data collection present a significant challenge to the formulation of evidence-informed cannabis policymaking.

The prevalence of cannabis use disorder in people using cannabis for medical purposes was estimated at 25% in a systematic review and meta-analysis, suggesting that changes in medical access could have a substantial impact on health burden [17]. Monitoring systems need to be developed and implemented to provide timely data on whether the new policies are achieving their intended public health objectives while mitigating potential harms. In the absence of a multi-faceted surveillance approach, Thai policymakers will lack the empirical evidence needed to make informed adjustments to cannabis regulations and identify new public health concerns that may warrant intervention.

Effective monitoring and evaluation of this unprecedented policy change in Thailand is of international importance. The issue of drug policy reversal is not unheard of, including the rolling back of New Zealand’s short-lived experiment with a regulated market for synthetic cannabinoids (2013–2014). As legal markets for adult non-medical cannabis emerge and mature in the Americas, Europe and beyond, the extent to which an established commercialised market of cannabis can be effectively reversed is a critical question for international policy makers. A key issue is likely to be presented by the competing interests of the commercialised cannabis industry versus public health interests. There is also a risk that the newly adopted medical cannabis framework could evolve into a de facto legal cannabis market. As seen in Australia, the expanding list of eligible conditions for which cannabis can be prescribed met with the implementation of a vertically integrated medical cannabis sector (i.e. company involved in all levels of distribution), which results in relatively quick and seamless access. Thai policymakers should avoid loosening such regulations if they intend to maintain an evidence-based medical cannabis policy.

AUTHOR CONTRIBUTIONS

Rasmon Kalayasiri: Conceptualization (equal); writing—original draft (equal); writing—review and editing (equal). Woraphat Ratta-apha: Conceptualization (equal); writing—original draft (equal). Jack Wilson: Conceptualization (equal); writing—review and editing (equal). Wayne Hall: Conceptualization (equal); writing—review and editing (equal). Tom P. Freeman: Conceptualization (equal); writing—original draft (equal); writing—review and editing (equal).

FUNDING INFORMATION

R.K. was funded by the Thai Health Promotion Foundation (64-00223; the Centre for Addiction Studies and 67-00411; the Alcohol Stop Drink Helplines). W.R. was funded by Addiction Psychiatry Fund, Siriraj Foundation, Faculty of Medicine Siriraj Hospital (DD004421). J.W. received no funding for this contribution. W.H. received no funding for his contribution. T.P.F. was funded by a United Kingdom Research and Innovation (UKRI) Future Leaders Fellowship (MR/Y017560/1).

DECLARATION OF INTERESTS

None.

https://onlinelibrary.wiley.com/doi/full/10.1111/add.70499