Drug Detection Times

How long will a positive drug test result continue?

Unfortunately there is no simple answer for how long a positive drug test result will continue. 

The exact time frame required to return a negative test will depend upon a large variety of factors. These factors include the health of the person, the type of test conducted and the strength, amount and history of previous consumption of the drug.

This section should help you to understand detection periods and provide a general guide regarding the detection periods for various drugs.


Detection Periods - Summary

Ever heard that casual use of "Marijuana will show a positive result for 3 months in a urine test", or even "six weeks" or even "4 weeks"?

Normally explanations of horrendously long detection periods such as these are mixed with some scientific facts (such as THC being highly fat soluble). Yes, marijuana is highly fat soluble, however it also has quite a short "half life" so that casual use of the drug is likely to only present a positive result for 1 to 2 days in a urine test (however this could be 30 days from regular or chronic use).

The time frame can vary from person to person simply because all people have different conditions of general health, different fluid intake, metabolism etc. We also have no idea exactly how strong the drug was to start with and we have no idea about the total amount of the drug that might have been taken (illicit drugs don't tend to be provided with fabulous labels displaying volume and  % strength or be separated into individually packaged "doses").

We've provided a comprehensive explanation of the issues below including the following information:

  • What is a detection period?
  • So can we just use the detection period tables?
  • Cut-off levels - what are they?
  • Understanding cut-off levels and impairment
  • Drug testing levels are different in each Country
  • Drug testing cut-off levels can be different in each Organisation
  • What are the major limitations?
  • Detection Tables

However if you are in doubt and facing a drug test, or if you want to responsibly self-manage consumption so that you won't show a positive result in a drug test with the added benefit that you also have much less chance of exposing yourself and others to risk; you can also test yourself in the privacy of your own home.


What is a detection period?

A detection period is the simply the amount of time after consuming a drug that a particular testing method can still show a positive result.

For some methods (blood or saliva) this is usually measured in hours or days and in other cases in days or weeks (urine or hair).


So can we just use the detection period tables?

Detection periods can vary dramatically between people due to many factors (such as speed of metabolism, gender, drug interactions, genetic traits, age of the person or the type and strength of drug and the amount and way in which it is taken). So any reference to detection periods needs to be taken as a very rough guide only.

Detection period tables should not be relied upon to determine detoxification time or to determine when a person will provide a negative result to a drug test. This page contains some useful information which should be helpful for people wanting to understand this issue more thoroughly.


Cut-off levels - what are they?

Drug testing normally involves establishing the concentration of a drug above a certain level rather than just finding the presence of any level of the drug. Interestingly, not many people are aware of this!

A “cut-off” is the concentration at or above which a laboratory will deem to be a "positive" result. Cut-offs are usually set arbitrarily by an independent committee/ government body and reflect what most laboratories can reliably duplicate, generally reflect some recency of use and attempt to avoid extraneous influences such as passive inhalation or naturally occurring amines etc.


Drug testing Cut-off levels are different in each Country

In Australia and in the United States, expert committees have formulated and published recommended cut-off levels for a number of drug classes in what are referred to as "Standards".

These cut-off levels are not exactly the same between countries, for example the opiate cut-off level for urine testing in the United States is 2000ng/ml whereas the cut-off level in Australia for the same drug is 300ng/ml. This is a fairly dramatic difference (US is 666% higher than Australia).


Drug testing Cut-off levels can be different in each Organisation

Some organisations also adopt different cut-off levels for various drug classes. This means that anybody purchasing a home drug test kit should check the relevant cut-off level that might apply before selecting a test.

Naturally it can be a waste of time and money relying upon a test kit if it uses a different cut-off level to what is actually applied in a policy.


What are the major limitations?

People often fall into the trap of just looking at a detection period table and expecting that the time period stated in the table will apply to them.

The problem with this is that although detection period tables can be helpful in providing a general guide, they also have major limitations. The following table presents some of these limitations.

Limitation In other words.... Which Means...
Everybody is different People have different metabolic rates, ages and general health status (for example fitness and disease). All people tend to break down drugs at different speeds. Even if 2 people consume the same amount of a drug, they will most likely have different concentrations of the drug in their system over time
Different route of Administration If a drug is smoked as opposed to injecting it, this could lead to markedly different detection periods For example taking opiates orally will lead to substantially different concentrations in the blood and subsequently alter the detection period
Drug consumption is different Some people might consume a large amount of a drug, while others consume less. Also some people might frequently consume a drug and others only occasionally. Frequent use of a drug can increase the amount of drug/metabolite in the body and take longer to remove
Cut-off levels are not always consistent Some Countries and Organisations use different Standard cut-off levels. For example the cut-off level for Opiates in the US is 2000ng/ml compared to 300ng/ml in Australia If a lower cut-off level is used, the drug detection period will be extended and vice versa.


Having noted these limitations, some detection tables are provided below. As with all information provided on this site, this information is subject to our disclaimer policy which can be viewed in full by following the link at the bottom of this page.

These tables assume that the Australian Standard cut-off levels are used for the applicable substances listed.


Detection Tables (Urine & Saliva)


SUBSTANCE/ ROUTE OF ADMINISTRATION Examples of Proprietary or Street Names
Medical Uses Urine Saliva
Amphetamine(Injected,oral, smoked, sniffed)
Dexamphetamine Black Beauties, Crosses, Hearts
Attention deficit hyperactivity disorder (ADHD), obesity, narcolepsy
1-3 days
12 hours
Cocaine (Injected, smoked, sniffed)
Coke, Crack, Flake, Rocks, Snow
Local anaesthetic, vasoconstrictor not available for medical use in Australia
0.5-3 days 1-2 days
Methyl-amphetamine (Injected, oral, smoked, sniffed)
Crank, Crystal, Glass, Ice, Speed
ADHD, obesity, narcolepsy not available for medical use in Australia
1-3 days 1-3 days


Hallucinogens and Other Compounds

Examples of Proprietary or Street Names
Medical Uses Urine Saliva
LSD (Oral)
Acid, Microdot
8 hours
0-3 hours
Psilocybin (Oral)
Magic Mushroom, Purple Passion, Shrooms
8 hours
0-8 hours
Amphetamine and Phenethylamine variants (Oral)
DOB, DOM, MDA, MDMA, MDEA, 2C-T2, 2C-B, PMA, MBDB, 4MTA Adam, Ecstasy, Eden, Eve, Nexus, STP, XTC
1-3 days
25 hours
Marijuana/Hash (active ingredient Tetrahydro-cannabinol) (Oral, smoked)
Grass, Herb, Hash, Hash Oil, Pot, Reefer, Smoke, Weed
Limited Access under special conditions (refer to TGA website and State Laws)
Casual user 1-2 days
Moderate user up to 10 days
Chronic user 10-28 days
up to 24 hrs

Opioids and Morphine Derivatives

SUBSTANCE/ ROUTE OF ADMINISTRATION Examples of Proprietary or Street Names Medical Uses Urine Saliva
Codeine (Injected, oral)
Aspalgin, Codiphen, Codis, Codral, Dymadon, Panamax Co, Mersyndol, Panadeine, Panalgesic
Analgesic, antitussive 1-2 days 2-3 days
Heroin (Injected, smoked, sniffed)
Diacetylmorphine, Horse, Smack
1-2 days
1-2 days
Methadone (Injected, oral)
Physeptone, Methadone Syrup
Analgesic, treatment for opiate dependence
3 days
24 hours
Morphine (Injected, oral, smoked)
Anamorph, Kapanol, Morphalgin, MS Contin, Sevredol
1-2 days
1-2 days



SUBSTANCE/ ROUTE OF ADMINISTRATION Examples of Proprietary or Street Names Medical Uses Urine Saliva
Beer, Wine, Spirits
Antidote for methanol poisoning
6-10 hours 12 hours
Barbiturates (Injected, Oral)
Phenobarbitone, Barbs
Anaesthetic, anticonvulsant, hypnotic, sedative, 
Phenobarbitone (anticonvulsant) is the only Barbiturate available for human medical purposes in Australia (also used by vets)
2-10 days
1-2 days
Benzodiazepines (Injected, Oral)
Ativan, Halcion, Normison, Rohypnol, Valium, Rivotril, Roofies, Serepax, Tranks, Xanax
Anxiolytics, anticonvulsant, hypnotic, sedative
Diazepam (Valium) 3-12 days
Oxazepam (Serepax) 1-3 days
Temazepam (Normison) 1-3 days
Alprazolam (Xanax) 1-3 days
Flunitrazepam (Rohypnol, Roofies) 1-2 days
Clonazepam (Rivotril) 3-8 days
Nitrazepam (Mogadon) 3-7 days
16-48 hours


Ok, if you've managed to make it all the way down here and still trying to work out if you might be positive or not - perhaps the best approach would be to test yourself.

Why not look over here and select a test kit to suit your needs and test yourself in the privacy of your own home