Arjan is a pioneer of modern cannabis genetics and one of the most influential figures in the global cannabis industry, with over four decades of experience spanning cultivation, genetics, pharmaceuticals, media, and regulation.

He is the founder of the Green House Coffeeshops in Amsterdam and the breeder behind legendary cultivars such as White Widow, Super Silver Haze, and Super Lemon Haze. His genetics and coffeeshops have collectively won more than 40 High Times Cannabis Cups, an industry record.

In 2001, Arjan was involved in securing one of the first government-issued medical cannabis cultivation licences in the Netherlands, granted by the Office of Medicinal Cannabis (OMC), supporting the early supply of medicinal cannabis to Dutch pharmacies. Due to regulatory conflict-of-interest rules related to coffeeshop ownership, he was not operationally involved, and his partner Franco Loja acted as Master Grower.

Arjan is also internationally recognised as the co-creator of Strain Hunters, a groundbreaking documentary and research series focused on the exploration and preservation of indigenous cannabis landraces. The series has been featured on VICE, VICE on HBO, National Geographic, VICELAND, and YouTube, and has played a significant role in preserving cannabis biodiversity and shaping modern breeding programs.

In 2005, Arjan was involved with AI Lab Swiss, one of Europe’s earliest Swissmedic-licensed GMP manufacturers of cannabinoid active pharmaceutical ingredients (THC and CBD), at a time when pharmaceutical-grade cannabis production was still in its infancy.

In 2016, he co-founded GH Medical with Heiko Hampsink, an open, evidence-based platform dedicated to cannabinoid science, biochemistry, and medical education. In 2018, GH Medical collaborated with the Government of Thailand, the Thai FDA, TISTR, and the Ministry of Public Health to deliver “An Introduction to Medicinal Cannabis”, shortly before Thailand became the first Asian nation to legalise medical cannabis.

Today, Arjan is active in EU-GACP and EU-GMP medical cannabis production, genetics, and international market development through Green House Thailand and Green House Energrow, supporting regulated medical markets in the EU, UK, and Australia.