Thai is a cultivar of Psilocybe cubensis, named after the wild mushrooms that grow on buffalo pasture in Thailand and that have been sold to tourists on Koh Samui and Koh Phangan since at least the 1980s. In the Netherlands it is sold as a grow kit and as spores. In Thailand every form of it is illegal: magic mushrooms are a Category 5 narcotic, and using them can mean up to a year in prison.
This site puts the two sides together. It explains what the Thai name does and does not tell you, what researchers documented on the islands, what the Thai and Dutch law say, how strong Thai turned out in the one laboratory study that measured it, and what to expect from the effects. Each page answers one question; pick a number from the menu above.
Thai at a glance
| Species | Psilocybe cubensis |
| Names on the label | Thai, Koh Samui, Koh Samui (Thai) |
| Wild in Thailand | on water buffalo and cattle dung, recorded 1989 to 1990 |
| Local name | hed kee kwai, the mushroom after the buffalo dung |
| Measured content | 0.88% psilocybin plus psilocin, dried (one study, 2024) |
| Shop's comparison | potency similar to Mexican |
| Effects start | after 20 to 60 minutes, lasting about 3 to 4 hours |
| Thailand | illegal, Category 5 narcotic |
| Netherlands | kit and spores legal to buy; mushrooms illegal once they appear |
Where to start
New to the subject: begin with the Thai cultivar, then the measured strength and the effects. Travelling to Thailand: read mushrooms in Thailand and the law before anything else. Buying a kit in the Netherlands: the grow kit guide compares the three Thai products and sets them next to other cultivars.
The featured kit on this page is the one we suggest for a first grow: fully colonised, no soaking, set up the day it arrives. Prices include VAT and come straight from Dutch-Smart. Products are for adults in the Netherlands.