Cannabis is the plant Cannabis sativa L. and the products made from it, valued mainly for cannabinoids such as THC, the compound behind the intoxicating effect, and CBD, which does not intoxicate in the same way. Whether a particular plant is called “hemp” or “cannabis” is a legal decision based on its THC content, not a botanical one. In Thailand the flower is currently a controlled herb that can be sold to the public only on a prescription, so this page explains the plant and the rules rather than pointing anyone to a shop.
The plant
The World Health Organization uses “cannabis” as an umbrella word for the psychoactive preparations made from Cannabis sativa, and names delta-9-tetrahydrocannabinol (THC) as the major psychoactive constituent. Substances with a structure similar to THC are grouped together as cannabinoids. Labels you will see on seed packets and menus, such as indica, sativa or ruderalis, describe types within one species; they all belong to Cannabis sativa L., a member of the Cannabaceae family.
Cannabis is usually grown for its female flowers. A plant-science review from McGill University explains that cannabinoids are made in stalked glandular trichomes, the tiny resin glands that crowd the female flowers. That resin also carries terpenes and flavonoids, which is why the flower is the part that matters for both medicine and regulation.
THC and CBD, and why the raw plant is different
The living plant makes mostly the acid forms of these compounds, THCA and CBDA. The same review notes that fresh flower contains relatively little THC and CBD and much more THCA and CBDA; the acids turn into the neutral forms through decarboxylation during post-harvest handling and storage, a conversion driven mainly by temperature and light. This is why a laboratory report lists both acid and neutral forms, and why heat matters in any preparation.
| Compound | What it is | Key point |
|---|---|---|
| THCA | Acid precursor made in the trichomes | Converts to THC with heat and time |
| THC | Main psychoactive cannabinoid | The number used to draw the hemp line |
| CBDA | Acid precursor of CBD | Converts to CBD with heat and time |
| CBD | Non-intoxicating cannabinoid | Purified CBD is the drug substance of an approved epilepsy medicine |
Hemp versus cannabis: a line drawn in law
Hemp and drug-type cannabis are the same species. What separates them is a THC limit written into law, and that limit differs between jurisdictions:
- European Union: hemp grown with farm support must be a variety with a THC content below 0.3%, grown from certified seed of catalogued varieties.
- United States: federal law defines hemp as Cannabis sativa L. with a delta-9 THC concentration of not more than 0.3 percent on a dry weight basis.
- Thailand: when the plant was removed from the narcotics list in 2022, extracts containing more than 0.2% THC stayed classified as narcotics. Under the current controlled-herb notification, cannabis and hemp are treated under one definition of the cannabis plant.
So “hemp” in one country can be “cannabis” in another. A product that is legal where it was made is not automatically legal where you live.
Which parts are used for what
- Female flowers (inflorescences): the main source of cannabinoids and terpenes, used for medicinal preparations and for extraction.
- Stems and stalks: fibre and the woody core. The European Commission describes hemp fibre as very similar to linen, with growing interest from the textile industry.
- Seeds: used as food, including animal feed, and grown for sowing under the variety rules above.
- Leaves: in Thailand, leaves and stems remain classed as general herbs; only the flower is a controlled herb.
Cannabis in Thailand today, briefly
The rule that matters is the Notification of the Ministry of Public Health Re: Controlled Herbs (Cannabis), B.E. 2568, in force since 26 June 2025. It keeps cannabis flower as a controlled herb and puts retail sales on a prescription-only basis:
- A member of the public may buy flower only with a prescription on the official form (PT 33) from an authorised practitioner, and a prescription may cover no more than 30 days.
- Sales through websites, social media, vending machines and other electronic channels are prohibited, and advertising cannabis flower through any commercial channel is banned.
- Sales are not allowed in places such as temples, dormitories and public parks, and flower may not be sold for smoking on the premises except as part of treatment by an authorised practitioner.
Extracts fall under the separate Ministerial Regulation on Cannabis or Hemp Extracts B.E. 2569, in force since 26 April 2026. On 22 September 2026 the Cabinet approved the draft Cannabis Control Act (formerly the Cannabis and Hemp Act) and sent it to the House of Representatives. It is not yet law; its stated aim is to limit cannabis use to medical purposes.
This page does not list or recommend shops. If you are searching for a “cannabis shop near me” in Thailand, the legal starting point is a medical consultation, not a storefront.
Health risks belong in the definition
The WHO lists harms linked with regular use, including impaired attention and memory and the likelihood of a dependence syndrome, marked by loss of control over use, in chronic users. It also notes that cannabis use can worsen schizophrenia in people who already have it. Anyone reading about the plant should read that part too.
Common mistakes
- Treating indica and sativa as different species. They are labels for types within Cannabis sativa L.
- Assuming hemp means zero THC. Hemp is defined by a ceiling (0.3% in the EU and the US), not by the absence of THC.
- Reading a THC number without checking the form. Fresh or raw material is mostly THCA, which converts to THC with heat.
- Assuming Thai shops can sell flower to anyone. Since June 2025, public sales need a prescription.
- Assuming a Thai purchase travels with you. Thai authorities urge travellers to check the laws of their destination, because cannabis remains a serious illegal drug in several countries.
Thai rules have changed several times since 2022 and the new bill is still before Parliament, so check the current notification and your own country’s law before acting on anything here.