Your opinion: Gamma radiation for decontamination of medicinal cannabis

A seed on a leaf with gamma rays going through the seed

It is no news that gamma radiation is utilized by companies that produce medicinal cannabis flowers in countries with national medicinal cannabis programs, such as The Netherlands and Canada. A recent study, published by Arno Hazekamp, Head of Research and Education at Bedrocan International BV, has sparked a discussion again, because the procedure remains controversial.

Pharmaceutical regulations demand gamma radiation treatment of herbal cannabis in order to meet strict safety standards regarding the (possible) microbial contamination of the plant. A study named “Evaluating the Effects of Gamma-Irradiation for Decontamination of Medicinal Cannabis” has analysed four different strains of cannabis, produced by Bedrocan, before and after the radiation process, and has tested changes in terpenes, cannabinoids and moisture content.

While no changes in THCCBD nor moisture content of the medicinal cannabis could be identified, the research showed damage to a few terpenes. “Some terpenes are reduced, but no new compounds are formed. This means terpenes are evaporated to some extent, but not degraded into new compounds. Gamma irradiation somehow accelerates the evaporation just a little bit, but does not kill or destroy your cannabis.”, Hazekamp suggests.

The study further concluded that gamma radiation remains the safest and most efficient technique to make sure patients, especially those that with compromised immune systems, receive a safe product. The original, full length research article, including discussion and conclusion, can be found here.

Patients’ organizations react to the procedure of gamma radiation

However, patients, consumers and activists remain sceptical and express concerns about gamma radiation.

According to the research of patients’ organizations, like Canadians for Safe Access, one of the side effects of gamma radiation is the production of a new type of chemicals, which don’t occur naturally. Cancer-producing chemicals can develop as well, when fat is exposed to the procedure.

Derrick Bergman (known from Encod and VOC) has published a paper with the clear title “Medicinal cannabis in the Netherlands: most patients prefer coffeeshop over pharmacy”.  In the document he expresses that some patients claim gamma radiation has negative effects on the quality of medicinal cannabis, while Bedrocan states that the process is a demand of the Office of Medical Cannabis.

The Dutch patients’ group PGMC (Stichting Patiënten Groep Medicinale Cannabis Gebruikers) points out that said study is missing the answer to one very important question: What happens to the irradiated products when vaporized/smoked or eaten?

In this article, we have collected a range of different opinions on this subject for you. Please feel free to share yours with us and the Sensi Seeds audience.

Gamma radiation for decontamination of medicinal cannabis – a collection of different quotes

It’s also important to remember that gamma-irradiation is not just done without good reason. It is meant to prevent the potential greater harm of infecting a patient with harmful microbes. In my paper several sources are cited where this actually happened. It is weighing two ‘bad’ choices (risk of infection vs. irradiation) and picking the most sensible one.We should all hope for the development of new sterilization techniques for cannabis in the near future. – Hazekamp reasons on [x]

…Gamma irradiation produces un-natural compounds (ionizing radiation causes a multitude of chemical changes)… – Reverend Ryan says on [x]

Why the obligatory Gamma radiation? And what is the effect?  – says James Burton, Founder of the Dutch medicinal cannabis program [x]

You are constantly irradiated by the sun. If you don’t tan, there is no problem. Something that is irradiated to kill germs DOES NOT become radioactive – otherwise everyone who goes outside into the sun would be a health hazard when they came in – not to mention a mass of cancer! – D. J. Walters commented on [x]

I don’t think irradiation will dissuade customers. There will be some initial grumbling and outrage, but it will be eventually accepted as the norm. Most of us use dried spices when we cook and that’s all irradiated. I don’t think it will be the issue that kills the program. Wouldn’t a blind test be a fun thing to try on this issue? – leaffan commented on [x]

Does radiating cannabis with gamma rays have an effect on the compounds? No, it just sterilizes any seeds.  – Steve Harris said on [x]

RADIATION????? I have never known a home grower that needed to use this kind of poison. Just another reason NOT to get your medicine from these people. Are they going to tell the patients if it’s been radiated or not? – Bmunro commented on [x]

Gamma irradiation does not eradicate mould spores… This is perhaps the biggest misconception about this unholy and unsafe procedure and now also proven to be ineffective too. So patients in the NL don’t only suffer from ineffective cannabis .. but from ineffective gamma radiation perpetrated on an inferior product and then put in unsterile inadequate packaging too. This is a crime and torture! – Jackie Woerlee commented on [x]

I wasn’t in favor of the gamma ray. – James Burton has a clear stance on the topic

What’s the point of irradiating medicine when the natural thing with organic supplement is better than what’s in our tobacco?? … – pfk 182 commented on [x]

I develop X-ray based irradiators for use in biological studies. The recent market development of medical marijuana has begun to look into treating marijuana as a standard agricultural product. I will not go into GMO vs Organic as I am not an expert on the subject. However; I can speak to say that irradiating organic material does not make the product radioactive. This is a common misconception among the general population which is simply not true. Irradiating organics is not the practice of sprinkling radioactive material onto the product. This does not happen. But it is using the energy release from a radioactive source in order to sterilize and kill the bacteria. Radiation is just invisible light with a different wavelength than what you get out of your flashlight. Your concerns are the same as fearing to eat something you pulled out of the microwave because the microwave radiation would poison you. Consider the sun, if you stand outside in the sun for a period of time your skin will burn. But if you go inside, away from the sun’s UV radiation, then you don’t continue to burn. Same concept. The alternatives to gamma/X-ray are using UV, which alters the chemical composition of the weed as well as the effects. Or chemical sterilization. – Robert commented on [x]

Prairie Plant Systems uses a sterilization process called gamma irradiation to ensure its product is free of bacteria and mold. And that indeed involves exposing it to radiation. On the other hand, irradiation is a common and approved method for sterilization, especially in the pharmaceutical and agricultural industries where quality control is tightly regulated. …ensuring that medical marijuana is toxin-free is important for patients with immune system deficiencies. Bedrocan B.V., the only legal producer of medical marijuana in the Netherlands, also irradiates its product. – states an article on [x]

Wow, so gamma radiation does convert fats/acids/terpenes in cannabis, which then makes it carcinogenic. Great – says Drifter on [x]

And this is one of the reasons I am returning to black market weed. It’s a higher quality, lower price, more reliable service and not radioactive…  – Steve commented on [x]

Gamma radiation for decontamination of medicinal cannabis – your opinion please!

Do you agree or disagree with the comments above? What are your thoughts on gamma radiation for the decontamination of medicinal cannabis? Are you for, or against it? Let us know what your point of view is. You can do so by commenting on this post in the section below.

To a fair, respectful debate!

  • Disclaimer:
    Laws and regulations regarding cannabis cultivation differ from country to country. Sensi Seeds therefore strongly advises you to check your local laws and regulations. Do not act in conflict with the law.


21 thoughts on “Your opinion: Gamma radiation for decontamination of medicinal cannabis”

  1. When I buy and consume something I expect it to meet my personal standards
    My only interest in gamma irradiation is how it effects my ability to consume the product I have purchased it doesn’t matter if the product I have paid for is medicine or food or any other item I will only buy products that meet my needs standards and requirements
    I have tried 14 gamma irradiated cannabis medications I have found these medications to all be unsuitable for my needs because they all produce an unpleasant peculiar taste and texture to the vapour which is impossible for me to consume because I have sensory sensitivity for taste and texture gamma irradiated products are not suitable for someone such as myself
    I have experienced non-irradiated cannabis for 30 years I have no problems with non-irradiated cannabis
    I have experienced three types of E-beam irradiated cannabis these did not suffer such spoilage as the gamma irradiated products
    In conclusion I am happy gamma irradiation is the common denominator it is a coincidence that the 14 medications I have tried were of no use to me I couldn’t even consume them they are gag worthy the vapour is extremely spiky like sandpaper and glass lacking in oil very hot and sharp with a peculiar taste that also hurts my chest I have totally eliminated any kind of gamma irradiated medications I only accept non-irradiated medications and the difference is night and day gamma irradiation is the single biggest destroyer of medical cannabis

  2. Adam MacDonald


    Why was this removed?

    I have issues with the recreational, legal side of cannabis in Canada. It seems the packaging does not need to inform of irradiation.
    I have no answers as to what happens when irradiated cannabis is combusted, I can tell you it smells and tastes horrible, and I believe the thc deteriorates very rapidly after irradiation due to low moisture content.

  3. This article quotes people from several sides of a debate, then asks for others opinions, are gamma rays safe? But no one, including the author, explains what gamma rays are. How many of you bothered to educate yourselves about what a gamma ray is or what gamma ray treatment involves? Dont you want to ask the author if he knows? or any of the experts that were quoted? An opinion from someone who can explain with evidence of how the process works and why that makes it safe or not is an opinion that will influence legislation on the matter. Dont go and read more opinions to find the answers to whether on not it is safe. Seek to understand how it actually works. Then come back here and educated some people.

    1. Scarlet Palmer - Sensi Seeds

      Hi there,

      Thank you for your feedback. I think perhaps you have misunderstood the idea behind this article so I wanted to clarify it. This is part of a series in which we collect opinions from a variety of sources and present them for our readers, in this case ‘Gamma Radiation For Decontamination Of Medicinal Cannabis’; the purpose of the article is not to explain what gamma radiation is, but to present different opinions on its use on cannabis. An explanation of what gamma radiation is, and how cannabis is treated with it, can be found by clicking one of the first links (

      This study also explains why pharmaceutical cannabis must be irradiated: “Because medicinal cannabis is often used by chronically ill patients affected by a weakened immune system, pharmaceutical regulations in countries such as The Netherlands and Canada specify that these products must adhere to strict safety standards regarding microbial contamination. When harmful microbes or fungal spores are inhaled during e.g., vaporizing or smoking, they may directly enter the bloodstream and cause opportunistic infections. Such contamination risks are not merely hypothetical: cases of chronic pulmonary aspergillosis associated with smoking unsafe cannabis are well established in the scientific literature (Llamas et al., 1978; Sutton et al., 1986; Marks et al., 1996; Szyper-Kravitz et al., 2001; Kouevidjin et al., 2003; Cescon et al., 2008; Bal et al., 2010; Ruchlemer et al., 2015). For those with compromised immune systems, such lung diseases could be even fatal (Hamadeh et al., 1988).”

      This information goes some way to explaining why this is a controversial topic, as there are those who distrust irradiation, and there are those who rely upon it to keep them safe. This is why we chose this topic for inclusion in the ‘Your Opinion’ series. I hope this explains what the intention of this article is, and that you continue to enjoy the blog.

      With best wishes,


      1. Scarlet is a paid shill. So obvious. And btw Pharmaceuticals cannabis doesn’t need to rradiate all the product. Just a have a small % of medicine available that’s irradiated for the very few medical patients that require it or want it. Which would be a small %. The real reason for irradiation is money. Protect their bad crops from not being legally allowed to be sold to the consumers due to failing microbial counts. It’s all about the money and nothing about your health. In all of Cannabis history, this plant as been consumed all across the world, grown in all types of dirty basements and never once was irradiated. This just started a couple of years ago to protect the money crop.

      2. Scarlet Palmer - Sensi Seeds

        Hi Jay,

        I am a paid writer for Sensi Seeds, which is indeed obvious from my author profile. However, I do not receive any revenue from the sale of cannabis (whether medicinal, recreational, irradiated, or grown in a dirty basement), nor the pharmaceutical industry.

        Your opinion on irradiated cannabis is just as valid as those which were collected for this article, none of which are specifically endorsed by Sensi Seeds. As mentioned in my previous comment, the point of the ‘Your Opinion’ series is to collect and present different and often opposing points of view on various topics. However, your claim that it’s “all about the money and nothing about your health” [sic] is untrue. It’s a lot cheaper to not irradiate cannabis, but this situation – “this plant as been consumed all across the world, grown in all types of dirty basements and never once was irradiated” [sic] – results (as mentioned in the sources in the article and in my previous comment) in sickness and even death among people with compromised immune systems.

        Hopefully this reply has cleared up your misconceptions.

        With best wishes,


  4. Lots of ignorance here. I agree that pure natural product out of the soil is always best. But even that product is eventually washed or cooked; otherwise you simply roll-the-dice and “hope” you don’t get sick. I don’t think anyone here is planning to place their weed in a salad spinner and wash it first; or in the oven to 160F for 5 minutes. I personally have no interest in inhaling hot mold and fungus spores deep into my lungs. To be clear, nothing is actually clean when you pull it out of the ground, nothing. You can only make it that way by some secondary operation…

  5. Does This kill the seeds ability to be germinated and will every country that works under TWEED do the same kind of gamma radiation to their products?

  6. None of it matters to me other than it is morally outragous. I was recently diagnosed with stage 4 liver cancer that has metastasized into surrounding tissue and given less than a year. I tried their chemo because I was told I would be given more quality time. I would be able to work even. Not so. It nearly killed me. Then a dear friend told me to research cannabis. Dec. 17, 2017 I started a protocol that includes .75 ml 96% THC or better daily, The highest THC content I can get through CanniMed is 22%. Without going into the math details it would cost me about 8X more than at my local dispensary. I couldn’t afford that so it doesn’t matter. Besides, I’m not about to be consulted over the phone by someone I’ve never met who I don’t even know lives in my country. This is the person whose hands I’m expected to put my life in? REALLY? So, it doesn’t matter. I see this information comes from the Head of Research fo Bedrocan. No bias there. Maybe if I believed the government hadn’t lied to me my whole life. But I do. So radiate away. It doesn’t matter to me. Canada, your MM program is irrelevant to me. Saskatchewan, Regina, if you close all the “homegrown” dispensaries ? Then guess what? You are irrelevant to me and the thousands like me. I don’t know wether I’m right or wrong but please don’t ask me to believe you have my best interests in mind. So for me? Radiate away. Besides, you Canadian politicians don’t believe I can be cured so your value to me is exactly zero.
    You ask me about radiated cannabis? Well, it just doesn’t matter to me, but this message does. Just doing my part to spread the truth faster.

  7. So prescription drugs kill hundreds of thousands of people a year. Opiates, antidepressants, cholesterol meds, heart medication anti psychotics and for some reason the drug industry is concerned with our health so much Cannabis needs to be irradiated. A plant should be grown and cultivated as a plant. Are all the fruit and veggies in stores irradiated, because I’m sure you will find germs and bacteria and fungi on it. I will stick with my own green thumb. Thank you.

  8. I believe that having a regulatory standard for cannabis is important. Setting a limit for microorganisms, aflatoxins, mold, pesticides, heavy meatals etc; needs to happen in a regulated system. That being said, the use of gamma irradiation is entirely unnecessary in more than one way ie; damage to terpenes, fatty acids, and that’s all we know from very limited research that we’ve done on it, cost/time are big factors as well and most importantly if you are a licensed producer of cannabis and require gamma irradiation because your product isnt meeting government guidlines than there is a bigger problem, and that is with how you are growing to begin with. If you are implementing proper sanitary protocol like having climate controlled rooms, HEPA/ UV filtration, decontaminating airlocks before entering a room, proper gear for personal, as well as testing and monitoring before/during/after each growing cycle, you will be producing a “pharmaceutical” grade product time and time again. Unfortunately what we have in Canada for our medicinal producers( and soon to be recreational too) is a miss match of people in the industry that either care about producing a amazing quality product or just want to produce as much as possible. As fast as they can to make money. Some of these LP’s will tell you on there websites wether they irradiate or not, some do not, but will tell you if you call them. From what I’ve researched from LP’s in Canada the ones to stay away from are the largest producers. The smaller more “artisnal” LP’s do not irradiate there cannabis and produce an obviously superior quality product in terms of appearance, potency, aroma etc. All in all, my opinion is that if we can avoid using procedures in cannabis cultivation that are not necessary(gamma irradiation) because they can be avoided with more thoughtful and cared for growing practices then thats the best way we can be growing!

  9. Ron Dominion

    URPs, just like concerns over GMOs, or Big Pharma, or Fukushima radiation etc. is baseless fear-mongering.
    A real risk:
    –Most…marijuana is contaminated with Aspergillus species, most often A. flavus and A. fumigatus.
    Ellenhorn, M.J., S. Schonwald, G. Ordog, J. Wasserberger. Ellenhorn’s Medical Toxicology: Diagnosis and Treatment of Human Poisoning. 2nd ed. Baltimore, MD: Williams and Wilkins, 1997., p. 395
    I am recovering from 18 months of treatment for an bronchial Aspergillus infection. One lung is ruined and will not recover. While I don’t know if this risk is important enough to require irradiation, the imaginary risks used to argue against it are absurd. Nature is worthy of awe and admiration, but the Appeal to Nature Fallacy most certainly is not.

    1. Rune Ellingsen

      “URPs, just like concerns over GMOs, or Big Pharma, or Fukushima radiation etc. is baseless fear-mongering.”

      Are you freakin’ insane Ron?

  10. darlene dickens

    Absolutely no,this is just ridicules nature is not to be tampered with!Just another way pharmaceutical company’s are altering nature.Test the plant not change the code of its biological make-up…smh.

  11. Saša Bajilo

    I don’t really see the point, why should the flower be sterile? Ok there must be strict quality control in regard to microbiological safety, but sterilizing the product that will be
    burned, or vaporized is crazy. Smoking and vaporization are the methods of sterilization of the plant material.

    1. Freda Stone

      The reason for any pharma companies to copy nature, is to make money!
      if they produce seeds that they can not control, (like the ones you collect and plant yourself, from organic haireloom seeds.) they don’t get paid! So they sterilise the seeds and you have to purchase more frankenstein e seeds….Welcome to GMO Cannabis!

      The point is, we should be able to take and medicate with, what ever we choose to do it with, and have no corporate bully tell us otherwise! They are already doing a big job controlling us with water, food, education, media, famous people, bogus organisations, such as the’ Pink Ribbon foundation’,(OH PLEASE!!!)and now medicinal Cannabis!!!! LOL

      Nature can do things 1000 times better than any human and if we leave nature be it puts everything back into balance.
      The problem now is that our biodiversity has been killed by chemical based products and seeds produced by such pharma business and organisations who control our freedom to ‘natural’ medicines, ‘natural’ Food, clean water, air and much more….the miss conceptions and the lies we are being fed is ridiculous!!

      This is the ‘New World Order’!!
      oh and when the TTIP bill passes! thats the end of our freedom, yet most people probably don’t know much about what the TTIP stands for nor what the GMO stands for…let alone be bothered to get politically involved.

      Please people don’t believe everything the man in the suit tells you! do your research and decide where you put your money and who u are directly affecting by the choices you make in the shops and online…is your money going to local farmers who are trying to do good? or are you supporting the ‘mono culture’ thats killing our environment, freedoms and Biodiversity.
      Its your choice! People have the power, they just need to wake up!

  12. James Burton

    The reason the Canadians use gama ray was they came to Holland and copy-cat everything the BMC and SIMM did.
    They came to SIMM several times,they bought our seeds and we export Cannabis to Canada.
    Money see-Money do..

  13. James Burton

    One of the points of discussion is there is other methods to use such as Low-pasteurized .
    Much safer and with a long track record.

  14. James Burton

    You need to talk about the URP’s ( unique Radiolytic property’s) that are not found in nature…but are in Bedrocan.

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    The Sensi Seeds Editorial team has been built throughout our more than 30 years of existence. Our writers and editors include botanists, medical and legal experts as well as renown activists the world over including Lester Grinspoon, Micha Knodt, Robert Connell Clarke, Maurice Veldman, Sebastian Maríncolo, James Burton and Seshata.
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