Cancer and cannabis use
Cannabis and cancer risk
Long-term, heavy cannabis use may raise the risk of testicular cancer. But generally, there is insufficient evidence of a cancer link from cannabis use to justify the Cancer Society taking a particular view on the referendum.
Potential cancer risks are summarised in our technical report here.
Cannabis research has been challenging because of its illegality. Further research is needed to help us understand the link between cannabis and cancer as currently there are a lot of unknowns.
A few medicinal cannabis products are approved in New Zealand so this is the safest way for patients to consume.
Information for people with cancer using cannabis
Some people with cancer have reported that cannabis helps in managing treatment symptoms including nausea, appetite loss, and pain. However, there is no evidence that it can ‘cure’ or ‘treat’ cancer. Evidence on which to base an assessment of the use and safety of medicinal cannabis products is limited.
If you choose to use recreational cannabis, you can lower your risk by following these points:
- Every form of cannabis use poses risks to people’s health. The only way to completely avoid these risks is by choosing not to use cannabis
- The earlier in life people begin using cannabis, the higher their risk of serious health problems
- The more frequently people use cannabis, the more likely you are to develop health problems, especially if they use on a daily or near-daily basis
- Smoking cannabis is the most harmful way of using cannabis because it directly affects the lungs.
- Don’t mix cannabis, tobacco and/or alcohol. Alcohol and tobacco are carcinogens so poly-use can be dangerous and can lead to addiction (for more lower-risk guidelines see Technical report)
About medicinal cannabis products
You need a prescription from a doctor registered to practice medicine in New Zealand before you can obtain any medicinal cannabis products.
A medicinal cannabis product is a dried cannabis product or a product in a pharmaceutical dosage form (eg, tablets or capsules) containing one or more cannabis-based ingredient(s) and no other prescription medicines or controlled drugs.
Cannabidiol (CBD) products are a type of medicinal cannabis product that has potential therapeutic value and contains little-to-no psychoactive substances. These products are typically available as capsules or oral liquid.
Other medicinal cannabis products may contain tetrahydrocannabinol (THC) or other psychoactive substances found in cannabis. These products may be available as tablets or capsules, or as dried flower intended for vaporisation.
Your doctor is the best person to advise you whether a medicinal cannabis product is a suitable treatment for you.For general information about the safety of medicines, see the Medsafe website.
Getting a prescription
Your doctor will have knowledge of your medical history, including any other medicines you are taking, and is best placed to advise you on the risks and benefits of using medicinal cannabis products.
You need a prescription from a doctor before you can obtain any medicinal cannabis product. Once you have a prescription, the doctor or a pharmacy will dispense the product to you. You cannot purchase medicinal cannabis products online or from a third party.
CBD products may be prescribed by any doctor registered to practice in New Zealand.
Other medicinal cannabis products can be prescribed by a doctor when:
- the product is an approved medicine, which means it has been assessed for safety and efficacy and been consented for distribution under the Medicines Act 1981, or
- the Medicinal Cannabis Agency has verified the product meets the medicinal cannabis minimum quality standard, or
- approval for a named patient has been granted by the Minister of Health following a recommendation from a relevant medical specialist or the Chief Medical Officer of a District Health Board.
Currently, SativexTM is the only medicinal cannabis product that is an approved medicine. This means that doctors can prescribe SativexTM without Ministerial approval.
A range of further medicinal cannabis products will become available over time as suppliers of medicinal cannabis products apply to the Medicinal Cannabis Agency to assess whether their products meet the medicinal cannabis minimum quality standard. Applications for product assessments opened on 1 April 2020.
For further information on the NZ medicinal cannabis scheme, visit the Ministry of Health website here.
 From a public health perspective, it's too early to say if the overall benefits of legalising cannabis will outweigh the harms. But clear indications it will improve justice and social inequities for Maori in particular
 These lower risk guidelines are adapted from Fischer, B., Russell, C., Sabioni, P., van den Brink, W., Le Foll, B., Hall, W., Rehm, J. & Room, R. (2017). Lower-Risk Cannabis Use Guidelines (LRCUG): An evidence-based update. American Journal of Public Health, 107 (8)”