Author : Dr Mike Garside
What Usually Shows Up On A Drug Test?
Drug test kits only find what they are built to look for. That single fact explains almost every surprise people run into with drug screening:
- A test that came back clear when it shouldn't have.
- A substance nobody thought to include.
- A result that raised more questions than it answered.
Whether you are an employer setting up a testing policy, a parent buying a home drug test kit, or someone about to be screened yourself, it helps to know exactly which substances appear on a typical UK panel and which ones quietly slip through.
A negative result only ever means "none of the drugs this particular test kit screens for were detected above the cut-off level", it never means "no drugs present".
The standard UK drug screen: five drugs, then everything else
Most drug testing in the UK still starts from the same core group. A basic 5 panel urine drug test covers cannabis, cocaine, opiates, amphetamines and benzodiazepines (or methamphetamine in place of benzodiazepines, depending on the test kit). Those five account for the overwhelming majority of positive results in UK workplace drug screening.
Everything beyond that is a deliberate choice. Ketamine, methadone, MDMA, tramadol, fentanyl, synthetic cannabinoids and alcohol all appear on extended multi-panel drug tests, but only if you specifically buy a kit that includes them.
Substances that usually show up, and for how long
The detection windows below reflect drug urine screening with a typical rapid urine drug test kit. They are a guide only, frequency of use, dose, metabolism, hydration and the sensitivity of the test all shift these figures considerably.
| Substance | Also known as | Typical urine detection window |
| Cannabis (THC) | Weed, marijuana, hash | 1–5 days occasional use; up to 45 days in heavy regular users |
| Cocaine (COC) | Coke, crack, charlie | 1–3 days |
| Opiates (MOP/OPI) | Heroin, morphine, codeine | 1–3 days |
| Amphetamines (AMP) | Speed, whizz | 1–6 days |
| Methamphetamine (MET) | Crystal, ice | 1–3 days (up to 5) |
| Benzodiazepines (BZO) | Diazepam, temazepam, alprazolam | 1–4 days; considerably longer with chronic use |
| MDMA | Ecstasy, pills, mandy | 1–4 days |
| Methadone (MTD) | Opioid substitution therapy | 1–8 days |
| Ketamine (KET) | Ket, special K | 1–3 days |
| Synthetic cannabinoids (K2) | Spice, Mamba, black mamba | 1–3 days, up to 5 days |
| Buprenorphine (BUP) | Subutex, Suboxone | 1–6 days |
| Barbiturates (BAR) | Phenobarbital, secobarbital | 1–8 days |
| Alcohol (ETG) | Ethanol | Up to 24 hours as ethanol; 24–72 hours as the ETG metabolite |
For the full published cut-off levels used across our range, see our reference table of drug test detection times and levels.
Cannabis (THC): the one that lingers
Cannabis is the most frequently detected substance in UK workplace testing, and it behaves quite differently from everything else on the panel. THC metabolites are fat-soluble, so they accumulate in body tissue and release slowly. A heavy daily user can test positive weeks after stopping, while a one-off user may clear in two or three days.
This is also where sensitivity matters most. A standard 50ng/mL cannabis strip and an ultra sensitive 20ng/mL strip can return opposite results on the same sample. Note too that cannabis is notoriously hard to pick up in saliva, which is why urine drug testing remains the better choice at home.
Cocaine, amphetamines and methamphetamine
The stimulant group clears the body quickly. Cocaine is typically detectable for only one to three days in urine, which means weekend use is often gone by a Tuesday morning test. This short window is exactly why cocaine tends to be under-represented in testing statistics despite high real-world prevalence in sectors such as hospitality, finance and construction.
Amphetamines run slightly longer at up to six days, and can be triggered by legitimate prescriptions as well as illicit use. Methamphetamine usually sits on its own separate panel line rather than being lumped in with amphetamines.
Opiates, and the synthetic opioids that hide behind them
The standard opiate line detects heroin, morphine and codeine. What it frequently misses are the synthetic opioids that have driven the sharpest rise in UK drug-related deaths, because chemically they look nothing like morphine to the test antibody.
Fentanyl needs its own dedicated panel. It is many times stronger than morphine and increasingly turns up mixed into other street drugs without the user's knowledge.
Nitazenes are newer still, sometimes more potent than fentanyl, and will not register on a standard opiate or fentanyl panel at all. If nitazenes are a realistic concern in your setting, they need a separate test.
Tramadol, oxycodone, methadone and buprenorphine are all separate panel lines too, and are commonly added to 13 panel urine drug test kits used in treatment and occupational health settings.
Benzodiazepines and prescription sedatives
Benzodiazepines appear on almost every standard panel because of how impairing they are, and because they are so often misused alongside opioids. Detection is typically one to four days, but chronic use can remain detectable for several weeks.
One important caveat: benzodiazepine screening is not uniform. Some benzodiazepines — lorazepam and temazepam in particular — can be missed by less sensitive strips, which is a good argument for choosing an ultra sensitive panel where sedative misuse is the main concern.
Shop benzodiazepines test kits here.
MDMA, ketamine and the club drug group
MDMA is usually detectable for two to four days and features on most 10 panel and above kits. Ketamine, by contrast, is not included on standard 5 or 6 panel tests despite rising UK use, and its short one to three day window means it is easily missed if testing is not prompt.
If ketamine specifically is a concern, a standalone saliva test gives a fast, easily observed result:
Spice and synthetic cannabinoids
Synthetic cannabinoids sold as Spice, K2 or Mamba are chemically unrelated to cannabis, so a THC panel will not detect them. They remain a serious concern in prisons, hostels and some workplace settings because of how unpredictable and potent they are.
Where Spice use is suspected in a vehicle, cell or communal space rather than in an individual, our surface wipe drug detection tests allow furniture, surfaces and powder residues to be swabbed directly.
Alcohol: breath, saliva or urine?
Alcohol is legal, but it is screened routinely in safety-critical roles — and how you test for it changes the answer entirely. Single use breathalysers and digital breathalysers measure current impairment. Saliva alcohol test strips do much the same thing without needing a breath sample.
ETG urine test strips work differently again: rather than measuring ethanol itself, they detect ethyl glucuronide, a metabolite that persists long after the alcohol has gone. That extends the window to roughly 24–72 hours, which makes ETG the standard choice for abstinence monitoring in treatment and probation settings. Many combined drug and alcohol saliva kits now screen for both on one sample.
Nicotine, vaping and cotinine
Nicotine is not a drug of abuse, but it is screened for in insurance medicals, some employment settings and increasingly by parents concerned about vaping. Tests detect cotinine, nicotine's primary metabolite, rather than nicotine itself. Our smoking and nicotine test kits and dedicated vape drug test kits cover this, the latter screening for nicotine, cannabis and synthetic cannabis together.
What usually does not show up
Just as important as knowing what a test covers is knowing what it does not. The following are routinely missed by standard UK panels:
- Anabolic steroids — these cannot be detected by a rapid onsite kit at all and require laboratory analysis.
- Most antidepressants — SSRIs such as fluoxetine and sertraline are not targeted by workplace screens.
- Newer new psychoactive substances — NPS chemistry changes faster than test panels can keep up.
- Solvents, nitrous oxide and many designer stimulants — generally outside the scope of point-of-care testing.
- Gabapentin, pregabalin and zolpidem — available as tests, but only on extended or bespoke panels.
We cover this in more detail in our guide to which drugs don't show up on a standard UK drug test.
Prescription medicines and false positives
A positive screening result is not the same as illicit use. Codeine-containing painkillers can trigger the opiate line, prescribed diazepam will show as a benzodiazepine, and legitimately prescribed amphetamine-based ADHD medication will register as amphetamine.
This is why confirmation matters: every rapid test is a screening test. Any non-negative result must be confirmed by an accredited laboratory method such as GC/MS before any disciplinary or legal action is taken. See our laboratory confirmation drug test packs and our guidance on false positive drug screen results.
How the sample type changes the answer
The same person can produce a positive and a negative on the same day depending on what is sampled. Saliva reflects very recent use; urine reflects the past few days; hair reflects months.
| Sample type | Typical detection window | Best suited to |
| Saliva | Hours up to around 48 hours | Roadside-style and onsite screening where recent use and impairment matter; collection is easily observed |
| Urine | 1–7 days for most drugs; far longer for cannabis | The most widely used option for workplace, pre-employment and home testing |
| Hair | Up to 90 days depending on length | Family court, custody proceedings and long-term abstinence monitoring; laboratory analysis required |
| Breath | Current alcohol only | Alcohol impairment testing at work or before driving |
| Blood | Hours to a few days | Clinical and evidential settings; invasive and lab-based |
Hair testing is the outlier here, it takes roughly seven to ten days for drug traces to become embedded in newly grown hair, so it is the wrong choice for detecting use in the last few days.
Matching the panel to the risk
Panel size is shorthand for how many separate drug lines a kit contains. Bigger is not automatically better; what matters is whether the panel covers the substances relevant to your setting.
| Panel size | Typically covers |
| 5 panel | Cannabis, cocaine, opiates, amphetamines, benzodiazepines (or methamphetamine) |
| 10 panel | The above plus methamphetamine, MDMA, methadone, ketamine or tramadol depending on configuration |
| 12 panel | Core groups plus ketamine, tramadol, oxycodone and fentanyl or other drugs |
| 13 panel | Core groups plus buprenorphine, barbiturates, PCP and tricyclic antidepressants varies from panel to panel |
For the widest single-sample coverage in a urine cup, with lower cut-off levels than a standard test and a built-in temperature strip for sample validation:
If saliva suits your situation better, onsite screening, observed collection, no toilet facilities needed, the 12 panel direct saliva kit covers the same ground including fentanyl:
Workplace drug testing: what employers usually screen for
UK workplace testing is normally carried out on urine or saliva, and most policies start with the standard five before adding whatever the sector demands. Construction and logistics tend to prioritise cannabis, cocaine and ketamine; healthcare settings need stronger opioid and benzodiazepine coverage; rail and other safety-critical roles almost always include alcohol.
Whatever the panel, testing must be consented to and underpinned by a clear written policy. Our guidance on where to start with workplace drug testing and writing a drug and alcohol policy covers the practicalities, and our workplace drug test kits and workplace saliva drug test kits are grouped by sector need.
A well-rounded 10 panel urine kit, popular with employers, schools and parents:
Frequently asked questions
Will a drug test show which specific drug I took?
A screening test shows which panel line reacted, not which specific compound caused it. An opiate positive does not distinguish heroin from prescribed codeine — only laboratory confirmation testing can do that.
Can a drug test detect how much I used?
No. Rapid tests are qualitative: they report above or below a cut-off level, not quantity consumed. A faint line is still a negative result provided it appears within the read time.
Does secondhand cannabis smoke show up?
Passive exposure at realistic levels is very unlikely to push someone above a standard 50ng/mL cut-off, though an ultra sensitive 20ng/mL test is more likely to pick up trace levels.
Why did my test come back negative when I expected a positive?
The three usual explanations are that the substance was not on the panel, the detection window had passed, or the sample was too dilute. Reading results outside the stated time window is another common cause, see our guide to reading drug test results.
Which test should I choose?
Start with the substances you actually need to detect and the timeframe that matters, then work backwards to the sample type and panel size. Our quick quiz narrows it down in under a minute, or our team can advise directly.
The key takeaway: a drug test is only as good as the panel behind it. Before buying, list the substances that genuinely matter in your setting, check they appear on the kit specification, and make sure you have a laboratory confirmation pack ready for any non-negative result.
The information in this article is provided for general educational purposes only and does not constitute legal or medical advice. Detection windows are estimates only and vary considerably between individuals depending on dose, frequency of use, metabolism, hydration, body composition and the sensitivity of the test used. They should never be relied upon to predict whether a specific person will test positive or negative on a specific day.
All urine drug test kits, saliva drug test kits, breathalysers and alcohol test kits supplied by UK Drug Testing are point-of-care screening tests. Any non-negative result should be confirmed using an accredited laboratory confirmation method before any employment, disciplinary or legal decisions are made.
Drug classifications under the Misuse of Drugs Act 1971 and the Psychoactive Substances Act 2016 change over time. Always check current UK legislation or seek professional legal advice if you need definitive, up-to-date guidance.
Workplace drug and alcohol testing must be carried out with the individual's consent and in line with a clear, communicated drug and alcohol policy. UK Drug Testing provides testing products and information to support awareness and responsible decision-making.
If you have concerns about your own or someone else's drug or alcohol use, please speak to a healthcare professional or a dedicated drug and alcohol support service.