PotHelp is now The Level, a straight up guide for people who use drugs.

All the information you’re familiar with is still available here.

About Cannabis

Select section:

If you take cannabis, will it show up on a drug test?

At some time in your life, an employer, a family member or the government may ask you to take a drug test. It’s important to understand what drug tests can detect and what might happen if you fail one.

Cannabis is usually tested for using hair, urine, saliva (spit) or blood. It is a drug that is commonly tested for, and it is easier to get reliable results than for many other substances.

Cannabis testing windows vary depending on how much you have used, how often and your individual body. For people who use cannabis heavily (several times a week), it is often detectable for longer than if it has only been used once. Generally, cannabis can be detected for 3–30 days in urine, 24–72 hours in saliva up to 48 hours in blood and up to 90 days in hair.

If you fail a drug test, this may affect your employment, government support, court cases or official licences or registrations. At work, you may face legal consequences, especially if you have put the safety of others at risk.

If you are using CBD or other cannabis products for medical reasons, you can speak with your doctor about what to do if you are expecting a drug test. It is legal to use these products with a prescription from a doctor in New Zealand.

The short answer is yes. Drug testing is not an 100% accurate science and will sometimes give a ‘false positive’ result. This is when a drug test says that a person has a drug in their system, when they actually do not. In these situations, the positive result has been caused by something else like medication or food.

In very rare cases you can get a false positive result for cannabis (THC) if you have eaten hemp food products  or been exposed to lots of secondhand cannabis smoke. More commonly, many medications can result in a false positive for cannabis. This includes efavirenz (an HIV medication), non-steroidal anti-inflammatory drugs, and stomach medication like omeprazole. These may not be the only medications that can show a false positive, and not everyone who takes these medications will have a false positive for cannabis. If you are expecting a drug test for cannabis and you are using a food or medication that may cause a false positive, speak with your doctor or the test provider beforehand to discuss your next steps.

Related stories

Popping the bubble: Quick tips if you're choosing to use drugs in Level 2

It can be a bit weird adjusting back to life outside your bubble, so we’ve pulled togther a few key tips to help you out if you choose to use drugs.

Find another drug