How Long Do Drugs Stay in Your System? Detection Times Chart

By the StartDrugRehab.com editorial team · Updated November 5, 2026 · Editorial policy

Quick answer

Most drugs show up in urine for about 1–4 days after occasional use, in blood and saliva for hours to about 2 days, and in hair for up to about 90 days. Frequent or heavy use can stretch urine windows to weeks, especially for marijuana and fentanyl.

Free detection-time checker

How long will it show up on a drug test?

Pick a substance, test type and how often it was used. Estimates are based on published research.

1 Substance

2 Type of test

3 How often

Usually detectable in urine · Weed / THC · once

About 1–3 days

What the test looks for: THC-COOH, an inactive metabolite of THC (urine); THC itself (blood, saliva)
On standard drug tests?: Yes — on standard 5-panel, 10-panel and federal workplace tests (50 ng/mL screening cutoff).
How fast it clears: THC is stored in body fat and released slowly, which is why frequent use is detectable for weeks.

Estimates, not a guarantee. Dose, how often and how long someone has used, body fat, hydration, metabolism and the lab’s cutoff all change the window. No calculator can tell you how a specific test will come out.

Full guide: how long weed stays in your system

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Drug detection times chart

This chart shows typical windows after one-time or occasional use. Click a substance for the full breakdown, including heavy or long-term use.

Typical detection windows after one-time or occasional use
Substance	Urine	Blood	Saliva	Hair
Alcohol	Up to about 12 hours, or 1–2 days with an EtG test	A few hours, up to about 12 hours	Up to about 12 hours	Usually not detected after one occasion
Marijuana (THC)	About 1–3 days	A few hours, up to about 1 day	Up to about 24–30 hours	Often not detected
Cocaine	About 2–4 days	Up to about 1–2 days	Up to about 1–1.5 days	Up to about 90 days
Meth	About 1–3 days	Up to about 1–2 days	Up to about 1–2 days	Up to about 90 days
Fentanyl	About 1–4 days	Hours, up to about 1 day	Not well established	Up to about 90 days
Adderall	About 1–2 days	Up to about 1–2 days	Up to about 1–2 days	Up to about 90 days
Xanax (alprazolam)	About 1–4 days	Up to about 1–2 days	Not well established	Up to about 90 days
Oxycodone	About 1–3 days	Up to about 24 hours	Up to about 1–1.5 days	Up to about 90 days
Shrooms (psilocybin)	Usually under 24 hours	Likely only hours	Not established	Not established
Kratom	Not well established — likely several days	Not well established — likely 1–3 days	Not established	Not established

How the main types of drug tests compare

Each kind of test looks at a different part of the body, so each one has a different window. From longest to shortest, the usual order is hair, then urine, then saliva, then blood.

Urine tests are by far the most common for jobs, probation and treatment programs. They usually pick up use from the past 1–4 days, and longer after heavy use. Most look for metabolites (breakdown products), not the drug itself.
Blood tests have the shortest window, usually hours to about 2 days. They are mostly used after accidents, in hospitals and for impaired-driving cases, because they show what is in the body right now.
Saliva (oral fluid) tests are quick swabs that cover roughly the last 1–2 days. They are popular for roadside and on-site testing.
Hair tests cover about the last 90 days with a standard 1.5-inch sample, but they cannot detect use from the last week or so. They are best at showing a pattern of repeated use.

What a standard drug test looks for

A “5-panel” test checks for five drug classes: marijuana (THC), cocaine, amphetamines (including meth), opiates and PCP. Federal workplace tests now also cover oxycodone, hydrocodone, MDMA, heroin (6-AM) and, since July 2025, fentanyl. “10-panel” tests add other drugs such as benzodiazepines, but what they include varies by lab.

Some substances are not on standard tests at all, including alcohol, kratom and psilocybin (shrooms). They have to be ordered specifically. Basic opiate screens also often miss fentanyl and oxycodone, which need their own tests.

Federal workplace urine cutoffs

A test is only “positive” above a set concentration. These are the federal screening cutoffs in effect since July 7, 2025. Clinical labs often use lower cutoffs, which can lengthen detection windows.

Drug class	Screening cutoff	Confirmation cutoff
Marijuana (THC-COOH)	50 ng/mL	15 ng/mL
Cocaine (benzoylecgonine)	150 ng/mL	100 ng/mL
Amphetamine / methamphetamine	500 ng/mL	250 ng/mL
Codeine / morphine	2,000 ng/mL	2,000 / 4,000 ng/mL
Oxycodone / oxymorphone	100 ng/mL	100 ng/mL
Fentanyl	1 ng/mL	1 ng/mL (fentanyl or norfentanyl)

What changes how long drugs stay in your system

How much and how often. A single use clears far faster than daily or heavy use, which can build up in the body.
The test and its cutoff. Every test has a cutoff level. Labs using lower cutoffs or more sensitive methods (like LC-MS/MS) can detect use for longer.
Metabolism, age and health. Liver and kidney function, age, genetics and other medications change how fast a drug is broken down.
Body fat and hydration. Fat-soluble drugs linger longer in people with more body fat. Diluted urine can lower concentrations, and labs check for dilution.

Because of these factors, published windows are ranges, not promises. Two people who used the same amount can test very differently, and no calculator can say how a specific test will turn out.

Can something else cause a positive test?

Yes. Screening tests (immunoassays) can react to other substances. Some cold medicines and antidepressants can trigger an amphetamine screen, prescription Adderall will test positive for amphetamine, and hand sanitizer vapor has produced positive EtG alcohol results. That is why a positive screen should be confirmed with a more precise lab test, and why it helps to tell the testing lab about any prescriptions.

When a drug test is the least of your worries

If you are looking this up because you are worried about an upcoming test, it may be worth asking a bigger question: is your use starting to cost you something, such as your job, your health, money or relationships? Needing to plan around a drug test is itself a sign some people use to decide it is time for help.

Treatment is more flexible than most people expect. Outpatient programs let you keep working, and many plans cover rehab under federal parity rules. You can get matched with up to 3 programs in about a minute, browse rehab centers by state, or call the number on this page to talk it through. It is free and confidential.

Detection times for other substances

See every substance side by side on our drug detection times chart.

Frequently asked questions

How long do drugs stay in your urine?

After one-time or occasional use, most drugs are detectable in urine for about 1–4 days. Frequent use lasts longer: daily marijuana use can show up for 10–15 days or more, and regular fentanyl use for 1–3 weeks.

Which drug stays in your system the longest?

Marijuana usually has the longest urine window, because THC is stored in body fat. Chronic heavy users can test positive for 30 days or more. In hair, most drugs can be detected for about 90 days.

What is the most common type of drug test?

Urine testing is the most common for employment, probation and treatment programs. It is cheap, well standardized and covers the past few days of use.

Does drinking water flush drugs out of your system?

Not meaningfully. Drinking lots of water can dilute urine, but labs measure dilution and may treat a diluted sample as invalid or ask for a retest. It does not speed up how fast the body breaks drugs down.

Do standard drug tests detect fentanyl?

Not basic opiate screens. Fentanyl needs its own test. Federal workplace testing added fentanyl in July 2025, and many clinics and treatment programs now test for it separately.