In 2018, the legalization of cannabis-based products for medicinal use in the UK marked a turning point in the country’s approach to medical cannabis. Glass Pharms entered the market with a mission that was simple yet ambitious: to create a sustainable, high-quality, and reliable domestic supply of medical cannabis, to replace products that were imported and often repurposed from recreational cannabis.
The company set out to produce cannabis that adhered to pharmaceutical-grade standards, ensuring patients could access the same product consistently and reliably. “Our aim was to create a domestic product that was high-quality and reliable, and that would enable patient numbers and businesses to grow based on a stable supply chain,” says CEO James Duckenfield.
A revolutionary manufacturing process
He explains that a cornerstone of Glass Pharms’ approach is its innovative continuous manufacturing process, unique in the marketplace – the 12-14 week cycle, during which plants travel through the facility from infancy to maturity, allows for unparalleled consistency, which is something that was missing in the UK market.
“We plant every day, we prune every day, we harvest every day. Our production facility is more like a factory,” he says, pointing out that although there are other growers in the UK, Glass Pharms was the first company to get a licence to sell cannabis flowers for cannabis-based products for medicinal use in humans (CBPMs).
“Ensuring a steady supply of fresh-to-market cannabis is crucial for maintaining the potency of cannabinoids and terpenes – the compounds responsible for cannabis’s medicinal effects and flavour profiles.”
One of Glass Pharms’ most significant breakthroughs lies in its approach to plant cultivation. By growing plants from tissue cultures rather than seeds, the company ensures genetic consistency across its crops. This method eliminates the variability and disease risks associated with seed-based cultivation.
Glass Pharms uses the most cutting-edge technologies in glasshouse horticulture to optimise for purity and consistency. With the aid of AI, remote sensors, monitoring and automation techniques, Glass Pharms is able to replicate growing results to new standards of reliability.
Proudly carbon negative
Sustainability is a guiding principle for Glass Pharms. Its facility in Wiltshire is a model of eco-conscious design. Spanning 2.4 hectares, it is the largest of its kind in the UK and operates as a carbon-negative entity.
The construction of a state-of-the-art glasshouse was completed in 2023 and in the same year the company started commercial operations. By partnering with best-in-class suppliers for greenhouse construction, civil engineering, and cleanroom facilities, Glass Pharms has created a world-class operation that is carbon-negative.
Duckenfield, who is very passionate about sustainability, says that through pairing with a sustainable energy power plant, both electricity and waste hot water needed for cultivation are sourced directly on-site. Glass Pharms uses waste heat from the anaerobic digestion plant to both heat and cool the facility, and advanced systems, such as LED lighting and waste-heat dehumidification, minimize environmental impact.
“Although sustainability remains a secondary consideration for many patients – only about 20% are willing to adjust their buying habits based on environmental factors – we believe that doing the right thing is non-negotiable. It’s good business practice as well as being good for the planet,” he affirms.
Partnerships and Industry Collaboration
Glass Pharms’ strategic partnerships have been vital for business growth. Last year, the company entered into a collaboration with the Advanced Plant Growth Centre at the James Hutton Institute to conduct a three-year medical cannabis research programme focused on developing improved cannabis strains. “We are very excited about this partnership. While it may not yield immediate returns, it has great long-term potential,” says Duckenfield.
Also last year, Glass Pharms has agreed with Releaf, an online clinic, on a landmark multi-million pound deal that will see the company grow 145kg of cannabis flower per month to supply CBPMs for Releaf’s patients.
“Releaf is dedicated to providing exceptional patient care, so they want to make sure that they have a reliable source of medicine that does not rely on imports. The partnership has been mutually beneficial, enabling the two parties to grow together by responding to patient needs with agility and precision.”
Given market developments and recent achievements, it may all look like plain sailing. However, Duckenfield points out that there are always challenges along the way and the more ambitious the business, the more challenges it may encounter, from regulatory hurdles to technical complexities. 
“We have built a truly world-class facility which is very, very different from a standard way of growing. Our approach requires a blend of commercial and technical expertise. We have had to overcome many technical challenges to devise a continuous manufacturing facility that delivers fast-to-market products. ”
“Credit goes to our operational team for their perseverance over the last 18 months and for overcoming all these complexities. Similarly, commercial growing expertise has also been absolutely vital. We brought commercial growers on board; pairing the two capabilities has been instrumental in our success.”
Scaling for the future
Duckenfield admits that the Glass Pharms facility was designed with scalability in mind. “We can double the glasshouse capacity within six months if needed, so 2025 will be about increasing volumes and serving more patients.”
He reflects that current estimates suggest around 50,000 patients use medical cannabis in the UK, a fraction of the numbers seen in countries like Australia (750,000 patients) or Germany (500,000+ patients). Glass Pharms expects domestic patient numbers to reach 100,000 by the end of 2025, driven by growing awareness, and by evolving regulatory attitudes.
“Our job now is to continue to enhance our processes and grow the business steadily and to make sure that we produce a product that is consistent and reliable.”
Looking back, Duckenfield can be rightfully proud of what Glass Pharms has achieved over the last few years, seeing how his passion for sustainability has shaped a vision that balances commercial ambition with social responsibility.
“Although I trained as a chemist, I haven’t really done very much in the way of chemistry. When I came across this opportunity, I clearly saw the potential for rekindling my chemistry knowledge to good use. And the journey has been fascinating. I’ve run different types of businesses, but this is one which I’m very passionate about,” he affirms.
While Glass Pharms for the moment remains focused on the UK market, it has received enquiries from international markets such as Germany and Australia, presenting exciting opportunities for future expansion. However, the company is determined to solidify its domestic presence before venturing abroad, aiming to establish itself as a trusted leader in the medical cannabis industry.
