Irradiated Cannabis: What Patients Need to Know
Irradiated Cannabis: What Patients Need to Know
If you’ve seen the words irradiated cannabis or gamma irradiated when looking at medical cannabis flower, you may have wondered what they actually mean. The word “irradiated” can sound concerning, but the process has a practical purpose: reducing microorganisms such as bacteria, yeasts and moulds.
So, does irradiation change medical cannabis? Does it affect THC or CBD? And is non-irradiated cannabis better? In this guide, we look at why some medical cannabis is irradiated, what the research tells us and what patients in the UK need to know.
Contents
What Is Irradiated Cannabis?
Irradiated cannabis is cannabis flower that has been treated with ionising radiation to reduce microorganisms such as bacteria, yeasts and moulds.
Cannabis is an agricultural product. Microorganisms can therefore be present on the plant or introduced during cultivation, harvesting, drying, processing and storage.
Medical cannabis flower must meet defined quality standards before it can be supplied to patients. Irradiation is one method manufacturers can use to reduce microbial contamination and help the finished product meet these requirements.
The process is not unique to cannabis. Irradiation technologies are also used for microbial control in other industries, including pharmaceutical and food production.
Why Is Medical Cannabis Irradiated?
The main reason is simple: microbial control.
Bacteria, yeasts and moulds can grow on plant material. Controlling these microorganisms is particularly important when a product is being produced for medical use.
The European Pharmacopoeia now includes a dedicated Cannabis Flower monograph. It sets quality requirements for cannabis flower supplied as a medicinal product.
Irradiation can be used as part of the manufacturing process to reduce microbial levels. However, not every medical cannabis flower needs to be irradiated. Some products meet the required specifications without this additional treatment.
This is why patients may see both irradiated and non-irradiated flower available through UK medical cannabis pharmacies.
Gamma vs Beta Irradiated Cannabis: What’s the Difference?
You may see different types of irradiation mentioned when researching medical cannabis. The two terms patients are most likely to encounter are gamma irradiation and electron-beam irradiation, sometimes described within the cannabis market as beta or e-beam treatment.
Gamma irradiation uses high-energy electromagnetic radiation. It can penetrate deeply through a product and is an established method of reducing microorganisms in pharmaceutical and other materials.
Electron-beam irradiation uses accelerated electrons rather than gamma rays. The treatment can be delivered quickly, although it has different penetration characteristics.
The technology is different, but the purpose is broadly the same: reducing microbial contamination while maintaining the quality of the product.
Does Irradiation Affect THC, CBD or Terpenes?
This is one of the biggest concerns patients have about irradiated cannabis.
Research suggests that gamma irradiation has little effect on the major cannabinoids THC and CBD.
A study published in Frontiers in Pharmacology compared medicinal cannabis before and after standard gamma irradiation. Researchers found no change in THC or CBD content. However, levels of some terpenes were reduced.
The terpene profile itself remained broadly similar. In other words, the same terpenes were still present, but the amount of some of the more volatile compounds decreased.
You can read the original study into gamma irradiation of medicinal cannabis.
More recent research has reached similar conclusions. A 2023 study found that gamma irradiation dramatically reduced microbial contamination while having little effect on cannabinoids, terpenes or moisture content.
You can read the 2023 study into gamma irradiation and cannabis quality.
Terpenes are the aromatic compounds that help give different cannabis flowers their distinctive smell. If you’d like to understand them in more detail, read our guide to cannabis aromas and terpenes.
Does Irradiation Make Cannabis Radioactive?
No. Irradiated cannabis is not radioactive.
Ionising radiation passes through the cannabis during treatment. This can damage or destroy microorganisms, but it does not mean radioactive material remains inside the flower.
The term “irradiated cannabis” therefore describes how the product has been treated. It does not mean that patients are being prescribed radioactive cannabis.
Irradiated vs Non-Irradiated Cannabis: Which Is Better?
Neither is automatically “better”. Both irradiated and non-irradiated medical cannabis can meet the required quality standards.
The main difference is how microbial levels have been controlled during production.
Irradiated flower has undergone an additional microbial-reduction process. Research suggests that THC and CBD remain largely stable, although some terpene levels may change.
Non-irradiated flower has not undergone this treatment. Instead, cultivation, processing, storage and other quality controls must keep microbial levels within the required specifications.
Some patients may have a preference based on aroma, terpene profile or their experience with a particular product. However, irradiation status alone does not tell you whether a medicine will be suitable for you.
Flower is also only one form of prescribed medical cannabis. Our guide to medical cannabis flower, oils and pastilles explains how the main formulations differ.
Is Irradiated Cannabis Safe?
Irradiation is an established method of reducing microorganisms in products, including pharmaceuticals and food.
Studies specifically looking at medicinal cannabis have found that gamma irradiation can significantly reduce microbial contamination without substantially changing THC or CBD levels.
That does not mean every prescribed cannabis product is irradiated. It means irradiation is one method manufacturers can use to achieve the required quality standards.
For more information about prescribed treatment and safety, read our medical cannabis patient information guide.
Should Patients Be Concerned About Irradiated Cannabis?
Seeing the word “irradiated” can understandably raise questions. However, irradiation itself should not automatically be viewed as a sign that medical cannabis is unsafe or lower quality.
The purpose of the process is to reduce microorganisms. Available research also suggests that the major cannabinoids remain largely stable after gamma irradiation.
There can be changes to some terpenes, so patients may notice differences between individual products. However, terpene content can also vary naturally between cultivars and batches.
If you want to know whether your prescribed flower has been irradiated, check the product information or speak to your pharmacist or clinical team.
Irradiated Cannabis FAQs
Does Irradiated Cannabis Contain Radiation?
No. The product is exposed to ionising radiation during treatment, but the process does not make the cannabis radioactive.
Does Irradiation Reduce THC?
Research into standard gamma irradiation has found no significant change in THC or CBD concentrations in the medicinal cannabis varieties studied.
Does Irradiation Affect Terpenes?
It can. Some studies have found reductions in certain volatile terpenes following gamma irradiation. However, the overall terpene profile can remain broadly similar.
Is Non-Irradiated Cannabis Better?
Not necessarily. Both irradiated and non-irradiated cannabis flower can meet medicinal quality standards. Individual products differ in cannabinoid content, terpene profile and other characteristics, so irradiation is only one factor.
Why Is Some Medical Cannabis Not Irradiated?
Some manufacturers can keep microbial levels within the required specifications through cultivation, processing and quality-control measures without using irradiation.
Can You Get Non-Irradiated Medical Cannabis in the UK?
Yes. Both irradiated and non-irradiated flower products can be available to UK medical cannabis patients. What can be prescribed will depend on product availability and what your clinician considers appropriate for your treatment.
Final Thoughts
Irradiated cannabis is simply cannabis flower that has undergone an additional process to reduce microorganisms such as bacteria, yeasts and moulds.
Research suggests that gamma irradiation can achieve this without significantly changing THC or CBD levels. Some terpene levels may decrease, but irradiation does not make cannabis radioactive.
Both irradiated and non-irradiated medical cannabis can meet the required quality standards. Rather than viewing one as automatically better than the other, it is more useful to consider the individual product and how it fits into your treatment plan.
If you’re already prescribed medical cannabis and have questions about a particular product, speak to your clinical team or pharmacist.
Curious if You’re Eligible?
Use our free eligibility checker to see whether a specialist medical cannabis assessment may be appropriate for you.
