Nimbin Health and Medical Research Council (NHMRC) Safer Cannabis use guidelines
Nimbin Health and Medical Research Council (NHMRC) Safer Cannabis use guidelines

Nimbin Health and Medical Research Council (NHMRC) Safer Cannabis use guidelines

The responsible consumption of cannabis is mainly a health issue. People make their own choices. It’s not the purpose of these guidelines to tell people how to behave, but to ensure they have solid evidence available so they can make educated and informed decisions to minimise health risks.

The form of cannabis use with the lowest health, social, legal and economic risk is abstinence. Even so, about 2 million Australians choose to use cannabis every year, and accept some degree of risk. Australians can reduce their health, social, legal and economic risks by following these guidelines.

  1. Moderation. It is recommended that social cannabis users only consume cannabis on no more than five days a week or less, trying to keep at least two days each week cannabis free. (This is not applicable for people using cannabis as a medication, e.g. relieving nausea from cancer chemotherapy) The effect from eating cookies lasts much longer. Users may only require one biscuit per day. Smokers/inhalers should not require more than 4 joints per day.
  2. Recognising harms that may arise. Cannabis is illegal. Possession or use can lead to arrest and a criminal record, loss of job or even worse. Be discrete. Don’t carry more than the ‘caution’ amount (NSW 15 grams). If cannabis is seriously affecting your life in important areas such as relationships, parenting, job or finances, then seriously consider reducing or stopping. Help is available if you find it difficult to slow down or stop. In Australia, more severe criminal penalties apply for: Australian Capital Territory – ≥ 2 non-hydroponic cannabis plants, or ≥ 25 grams of cannabis plant material; South Australia –  ≥100 grams of marijuana, ≥ 20 grams of hashish, ≥ 1 non-hydroponic plant or cannabis smoking equipment; Northern Territory –  ≥ 50 grams of marijuana, ≥ 1 gram of hash oil, ≥10 grams of hash or cannabis seed, or ≥ 2 non-hydroponic plants; New South Wales –  ≥ 15 grams of cannabis; Victoria – ≥ 50 grams of cannabis; Tasmania – ≥ 50 grams of cannabis; Queensland –  ≥ 50 grams of cannabis; Western Australia – ≥10 grams of harvested cannabis and/or a used smoking implement.
  3. Young People. Encourage young people who are likely to experiment to delay consuming cannabis until their body and mind have matured as drug use may affect physical and/or cognitive development. Impress on young people the need for moderation and responsibility. Avoid using in the presence of children. Do not smoke in confined areas with children or non-smokers present. “Passive smoking” is not confined to nicotine. Be aware that as an adult you are always a role model.
  4. Potency and Contaminants. The strength of different cannabis strains may vary widely. If you are going to use a new batch of cannabis, only try a small amount first. When purchasing any form of cannabis there is no certainty regarding fertiliser, fungicide, or insecticide use, how it is grown, or what affect that might have on health outcomes. Under prohibition without standards or quality control or regulation, the only way to be certain how a cannabis plant is grown is to watch it grow.
  5. Pregnancy. Women who are pregnant, breast feeding or might soon become pregnant should refrain from using cannabis. If they still choose to use cannabis, they should minimise their quantity and frequency of use, and avoid using tobacco.
  6. Driving. Do not drive a car or operate heavy machinery if impaired by cannabis. To make sure you are safe, allow at least a few hours before your last use of cannabis and driving. If you have used alcohol and cannabis, allow at least twice as long. Under drug driving legislation operating in NSW, police can test a car driver’s saliva at the roadside for cannabis (and other drugs). A positive result is an offence (evidence of impairment is not required). Tests stay positive for at least 3-4 hours after someone has taken cannabis. The duration for tests to still show a positive result is not certain and may be as long as 9 days after exposure. Penalties in NSW are over $1,000 fine and license disqualification for 6 months.
  7. Mental Health. If you have ever had a serious mental illness, or you have a family history of serious mental illness, it might be better to avoid cannabis and all other powerful mood altering drugs. If you still want to use cannabis, use as little as you can. Always have someone with you when you use to make sure you keep to your limits.
  8. Tobacco. Do not to mix tobacco with cannabis. Nicotine is addictive. Smoking with tobacco will often lead to you using more cannabis by virtue of the nicotine addiction.
  9. Smoke harms lungs. Consuming cannabis by inhaling the vapour from a vaporiser or eating foods made with cannabis are both less damaging to lungs than inhaling cannabis smoke, but the results of eating cannabis are less predictable. Cookies can be stronger and last longer than smoking, and can take up to an hour to take effect, so with edibles it’s more difficult to estimate the dose needed. Many people have already switched from smoking cannabis to inhaling cannabis vapour.
  10. Smoking Implements. Avoid using plastic bottles, rubber hoses, PVC, aluminium or foil to smoke cannabis – these all give off toxic fumes when hot (you run fewer health risks with a pipe made from glass, steel or brass.)
  11. Sharing. When you share joints, pipes or bongs you can also share germs and infections. Individual joints, pipes or bongs are preferable. Clean bongs or pipes after use.
  12. The environment. Make sure that you discard any smoking implements, waste, or roaches carefully and responsibly. Don’t start a fire through carelessness. Left over organic waste should go into compost.

Reference: Chapter 11, “Cannabis: a harm reduction perspective” by Andrew Bennett, in the European Monitoring Centre for Drugs and Drug Addiction (EMCDDA) publication: “A cannabis reader: global issues and local experiences”, available in pdf form at

These guidelines will be revised as better medical evidence comes to hand.

March 2016: Revised

July 2008: NHMRC (Nimbin Health and Medical Research Council)

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