If you only read one set of Thailand cannabis buying tips before your trip, make it this one. The rules here have moved fast, and a lot of what you will read online is out of date. Cannabis came off Thailand’s narcotics list in June 2022, but in June 2025 the government reclassified cannabis flower as a controlled herb under the 2025 controlled-herb rules, which means every legal purchase now runs through a quick medical certificate called a PT33. None of that should put you off. It just means buying smart instead of buying blind. Here is how to do it right, from the counter at How High in Koh Samui.
1. Know the Current Rules Before You Walk In
The single biggest mistake tourists make is assuming cannabis is a recreational free-for-all. It is legal, but regulated. Since June 2025, buying cannabis flower legally requires a PT33 medical certificate, which a licensed dispensary arranges for you on the spot in a few minutes. You do not need to sort anything out in advance, but you should walk in expecting a short, legitimate process rather than a grab-and-go.
2. Buy Only from Licensed Dispensaries
A licensed shop displays its license, employs a certified practitioner who can issue your PT33, and sells lab-tested product with clear labels. An unlicensed seller offers none of that. The difference shows up in both your legal safety and what you actually smoke. When in doubt, look for the license on the wall and a staff member who can explain where the flower came from.
3. Understand the PT33 Certificate
The PT33 is not red tape designed to slow you down. It is the document that makes your purchase legal, issued in store by a qualified practitioner after a brief chat about what you are looking for. Keep it with you while you have product on you. We explain the whole process in our guide to PT33 consultations, but the short version is: it takes minutes and a good shop handles it for you.
4. Ask About THC, and Be Honest About Your Tolerance
Thai-grown flower and imported Cali genetics can sit at very different strengths, and the edibles especially can catch people out. Tell the budtender how experienced you are and what effect you want, then let them steer you. A good one would rather sell you the right jar than the strongest one.
5. See and Smell Before You Buy
One of the joys of a proper dispensary is that nothing is a mystery bag. Ask to see and smell the flower. Fresh, well-cured bud has a loud, clean nose and sticky, frosty structure. If a shop will not show you what you are buying, shop somewhere that will.
6. Never Smoke in Public
Public consumption is treated as a public nuisance and can bring a fine of up to 25,000 THB. Beaches, streets, parks and anywhere near a temple are all off limits. Enjoy it in private accommodation or a licensed lounge instead. If your hotel says no, that is what weed delivery in Koh Samui to a private villa is for.
7. Mind Your Manners Around Thai Culture
Thailand’s tolerance comes with an unspoken deal: be discreet. Do not be visibly high around families, temples or anywhere it would embarrass your hosts. We cover the full do’s and don’ts in our Thailand weed etiquette guide, and it is worth a read before you go out.
8. Never Carry Cannabis Across a Border
This is the rule with the heaviest penalties anywhere in the region. Whatever you buy in Thailand stays in Thailand. Do not post it home, do not pack it, and do not carry it onto an international flight. Finish what you buy or give it away before the airport.
9. Avoid Street Sellers and “Tourist Deals”
Tourist-heavy areas attract fake shops and overpriced product pushed by aggressive sellers. For reference, at a licensed shop like How High, Thai flower starts around 150฿ a gram, imported Cali runs 450–800฿ a gram, and sealed Cali packs start near 2,400฿ for 3.5g, so you can quickly spot a tourist-trap markup. A real dispensary leads with education and transparency, not pressure and “special tourist prices.” If it feels like a hustle, it is one.
10. Start Low, Especially in the Heat
Tropical heat, a few beers and an unfamiliar edible is a combination that ends a lot of holidays early. Start with a small amount, give it time, and stay hydrated. You can always have more. You cannot have less.
Where to Start in Koh Samui
If you are on the island, come and put these tips to use with us. Browse the imported Cali packs, the value-friendly Thai weed shelf, or the solventless concentrates, and let the team sort your PT33 while you choose. Two shops, both easy to find: How High in Chaweng and at Fisherman’s Village in Bophut.
