How Long Do Drugs Stay in Your System? A Practical Guide to Drug Test Windows

If you’ve ever wondered how long a drug stays detectable in the body, you’re not alone. Detection windows vary widely depending on the substance, the type of test, and individual factors. This guide provide

s a practical overview of common drugs, typical detection windows for urine testing (the most common workplace test), and how testing methods can affect results. Keep in mind that these are general ranges and can vary from person to person.

Understanding the basics

Test types: Urine tests are the most common in occupational health and some law-enforcement settings. Blood, saliva, and hair tests are also used in certain situations. Hair tests can detect drug use over a much longer period but are less commonly used for routine workplace testing.

Factors affecting detect-ability: frequency of use, dose, metabolism, body mass, age, hydration, kidney and liver function, and the specific test cut-off levels. Even with the same substance, one person might test positive longer than another.

Common drugs and typical detection windows (urine testing)

Cannabis (THC)

- Occasional use: up to 3 days

- Moderate use: 5–7 days

- Chronic/heavy use: 10–30 days (and in some cases longer for very heavy use)

Cocaine

- Typically detectable for 2–4 days

- Heavy or chronic use can extend to 7 days

Opiates (including heroin, morphine, codeine)

- Generally detectable for 2–3 days

- Some formulations or higher doses can extend to 4–5 days

Amphetamines (including many prescription stimulants)

- Usually detectable for 2–3 days

- Some extended-usage patterns can reach up to 4–5 days

Methamphetamine

- Typically detectable for 2–5 days

- Heavy, long-term use can extend longer

MDMA (ecstasy)

- Usually detectable for 2–4 days

Benzodiazepines

- Short-acting benzos (e.g., lorazepam, oxazepam): 1–5 days

- Intermediate-acting (e.g., temazepam): 3–7 days

- Long-acting (e.g., diazepam): 1–3 weeks for infrequent use; longer with regular use

Barbiturates

- Short-acting: about 1–2 days

- Long-acting: 2–3 days or longer with regular use

Nicotine (cotinine, for tobacco users)

- Detectable for 1–3 days after last use for cotinine (often longer in heavy users)

Hair testing windows (context and contrasts)

Hair tests can detect drug use over months, not days. Typical interpretation:

- About 7–14 days of growth are needed before a drug becomes detectable in hair

- Once integrated, substances can be detected for up to 90 days or more, depending on hair length and testing standards

Use cases: longer-term use history, legal investigations, or certain regulatory programs rather than routine workplace screening

Important caveats

Detection windows are approximate. Individual factors can shorten or lengthen these periods.

Some drugs may be detectable in some test screens but not others (e.g., a test with higher cut-off levels might miss very low-level use).

Prescription medications and legitimate medical use can affect results. Always inform the testing program about any prescribed medications.

The purpose of testing and proper interpretation should always be guided by your employer’s policy and the testing laboratory’s guidelines.

Practical takeaways

If you’re facing a drug test, understand that recent use is more likely to show up than distant use, especially for substances with short detection windows.

For individuals in safety-sensitive roles, even a single use can have implications for testing results and job duties. Always consult with a healthcare or occupational health professional if you have questions about permitted or prescribed medications.

If you’re an employer, clear policies, education about substances, and fair testing practices help maintain safety while respecting privacy.