Test tubes in a rack with sample being taken from one of them

How Long Can Drugs Be Detected in Urine and Blood?

Urine and blood testing guide

Drug Detection Times

Compare indicative detection periods for urine and blood samples. Individual results can vary considerably.

✓ Sample-specific guidance ✓ Accessible comparison tables ✓ Laboratory testing available
Urine Often provides longer detection periods
Blood Usually provides shorter detection periods
Important Detection does not establish impairment

How long do drugs remain detectable?

No single detection period applies to every person.

The window depends upon the substance, sample and laboratory method.

A result only reflects the sample collected at that time.

Choosing urine or blood testing

Urine commonly supports general and workplace drug screening.

Blood usually reflects a shorter period after substance exposure.

Neither sample proves impairment without wider professional assessment.

What affects the detection window?

Several interacting factors can shorten or extend detectability.

1

Dose and frequency

Higher doses and repeated use may extend detection.

2

Metabolism

Individual metabolism changes how quickly substances are processed.

3

Body composition

Some substances or metabolites can persist within body tissues.

4

Health and age

Liver, kidney and general health can affect clearance.

5

Test and cut-off

Sample type, method and cut-off influence reported detection.

Indicative detection times in urine

Compare typical urine detection periods in the accessible table below.

Substance Indicative urine detection period
Alcohol 6–24 hours
Amphetamines 1–3 days
Barbiturates: short-acting 1–2 days
Barbiturates: long-acting 2–4 weeks
Benzodiazepines 3–7 days for short-acting; 4–6 weeks for long-acting
Cannabinoids 3–30 days, depending upon usage frequency
Cocaine 2–3 days
Codeine 1–2 days
Dihydrocodeine 1–2 days
Ephedrine 1–4 days
Ketamine 14 days
LSD 1–3 days
MDMA 1–3 days
Methadone 2–7 days
Methamphetamines 3–5 days
Methaqualone 10–15 days
Morphine 2–3 days
Phencyclidine (PCP) 1–8 days
Propoxyphene 1–2 days

Indicative detection times in blood

Compare typical blood detection periods in the accessible table below.

Substance Indicative blood detection period
Alcohol 1–12 hours
Amphetamines 12–24 hours
Barbiturates: short-acting 1–2 days
Barbiturates: long-acting 1–3 weeks
Benzodiazepines 6–48 hours for short-acting; 1–4 weeks for long-acting
Cannabinoids 1–7 days
Cocaine 1–2 days
Codeine 1–2 days
Dihydrocodeine 1–2 days
Ephedrine 1–2 days
Ketamine 1–3 days
LSD 2–3 hours
MDMA 1–2 days
Methadone 1–3 days
Methamphetamines 1–3 days
Methaqualone 2–3 weeks
Morphine 1–2 days
Phencyclidine (PCP) 1–3 days
Propoxyphene 1–2 days

Need laboratory drug testing?

Compare available tests before choosing your sample and screening panel.

Choose the Right Test

Collection list

Alcohol Tests
Alcohol Tests

Alcohol Tests

Drug Tests
Urine container

Drug Tests

Postal Tests
Home test kit package

Postal Tests

Chain of Custody Drug Tests
Urine specimen containers with client details and a chain of custody form

Chain of Custody Drug Tests

Patient Reception

76 Wimpole Street, London.

W1G 9RT.

Monday-Friday: 7AM - 7PM

Saturday: 7AM - 1PM

Sunday: Closed

Get directions