Psilocybe samuiensis, also known as Koh Samui or Thai is classified as a rare strain but it bears high popularity amongst knowledgeable users. The species originates from the Thai province of Ranong, specifically from the island of Koh Samui, from where it inherited its name. Its identity has caused years of contentious debate, after which it became the first of the Mexicanae group of species discovered outside of the New World. Psilocybe samuiensis was found by ethnomycologist John Allen.

Psilocybe Cubensis Koh Samui, with a moderate to high potency, is often mixed into fruit smoothies and milkshakes. Because it is known to be one of the most potent strains around, Psilocybe Cubensis Koh Samui is categorized as a super strain. It is resistant to contamination and it is a fast colonizing strain.