How Long Does THC Stay in Your System? Timelines by Test Type

Unlike alcohol, which your body metabolizes and eliminates within hours, THC is fat-soluble. When consumed, THC is absorbed into fatty tissues throughout the body and then slowly released back into the bloodstream for metabolism. This is why THC metabolites can be detected long after the psychoactive effects have worn off.

The primary metabolite that drug tests look for is THC-COOH (11-nor-9-carboxy-THC). This inactive byproduct is produced by your liver as it processes THC and can linger in body fat for days to weeks depending on several personal factors.

It's important to understand: a positive drug test does not mean you are currently impaired. It means you consumed THC at some point within the detection window.

Different drug tests measure different biological samples, each with its own detection timeline:

Urine test (most common):

• Single or infrequent use: 3 to 5 days
• Moderate use (a few times per week): 7 to 14 days
• Daily use: 15 to 30 days
• Heavy daily use over months: 30 to 60+ days

Blood test:

• THC is detectable in blood for 1 to 2 days for infrequent users
• Heavy users may test positive for up to 7 days
• Blood tests are less common for employment screening but used in some legal contexts

Saliva test:

• Detection window of 24 to 72 hours for most users
• Increasingly used for roadside testing and some employment screenings
• Measures THC itself (not metabolites), so it reflects more recent use

Hair test:

• Detection window of up to 90 days
• Tests a 1.5-inch hair sample, which represents approximately 3 months of growth
• Less common but used in some industries and legal situations
• Can be unreliable for infrequent or light use

The timelines above are general ranges. Your actual detection window depends on several personal variables:

Frequency of use: This is the single biggest factor. A one-time user will generally clear THC metabolites within a week. A daily user may need 30 or more days. Heavy, long-term daily users have been known to test positive for 60 to 90 days after stopping — this is due to accumulated THC stored in body fat.

Body fat percentage: Because THC is stored in fat cells, people with higher body fat percentages tend to retain metabolites longer. During exercise or weight loss, stored THC can actually be released back into the bloodstream, temporarily increasing metabolite levels.

Metabolism: Individuals with faster metabolic rates process and eliminate THC-COOH more quickly. Age, genetics, physical activity level, and overall health all influence metabolic speed.

Potency and amount consumed: Higher-THC products and larger quantities produce more metabolites, which take longer to eliminate. A single hit of 20% flower produces less THC-COOH than multiple sessions with 30% flower.

Method of consumption: Edibles produce a different metabolic pathway (11-hydroxy-THC is produced in the liver), which can result in slightly different detection characteristics compared to smoking or vaping.

Hydration: Hydration levels affect urine concentration but do not speed up actual THC elimination. Dilute urine may produce a lower concentration reading but can also trigger a retest if the sample appears too diluted.

Standard urine drug tests (immunoassay) look for THC-COOH, the metabolite produced when your body processes Delta-9 THC. This metabolite is produced regardless of how the THC entered your system:

THCa flower: When smoked or vaped, THCa converts to Delta-9 THC, which metabolizes into THC-COOH. You will test positive.

Delta-9 gummies: Already contain active Delta-9 THC. You will test positive.

Delta-8 products: Delta-8 THC metabolizes into a slightly different metabolite, but standard immunoassay drug tests do not distinguish between Delta-8 and Delta-9 metabolites. Delta-8 use will typically trigger a positive result on most standard drug tests.

CBD products: Pure CBD isolate should not cause a positive THC test. However, full-spectrum CBD products contain trace amounts of THC (up to 0.3%), which could potentially accumulate with heavy daily use and produce a positive result, though this is uncommon.

The bottom line: if you use any THC-containing hemp product and face drug testing, plan accordingly. There is no reliable way to predict exactly when you will test clean.

There's no shortage of products and home remedies claiming to flush THC from your system quickly. Here's what the evidence actually supports:

"Detox drinks" and supplements: Most work by temporarily diluting your urine, not by actually removing THC from your body. Some contain creatine and B vitamins to mask the dilution, but results are unreliable and labs are increasingly testing for unusual sample characteristics.

Drinking large amounts of water: Excessive water consumption before a test dilutes urine and may lower the metabolite concentration below the detection threshold, but it can also flag the sample as diluted, requiring a retest.

Exercise: Regular exercise can slightly speed up metabolism and fat burning, which helps eliminate stored THC over time. However, intense exercise in the days immediately before a test can temporarily release stored THC-COOH from fat cells, potentially increasing levels. If you're approaching a test, moderate or avoid strenuous exercise for a few days prior.

Niacin, vinegar, bleach: These are internet myths. None of these reliably clear THC metabolites and some can be harmful.

Time: The only reliable method for clearing THC is time and abstinence. This isn't the answer anyone wants to hear, but it's the only one supported by evidence.

If you know you'll face a drug test, plan ahead. Here's a practical framework:

If you're an infrequent user (once or twice a month): You'll likely test clean within 3 to 7 days of your last use. A home test kit (available at most pharmacies) can help you verify before the actual test.

If you're a moderate user (a few times per week): Allow at least 2 to 3 weeks. Use a home test kit at the 14-day mark to check your status.

If you're a daily user: Allow at least 30 days, potentially longer. Start with a home test kit at the 3-week mark and test weekly until you get consistent negatives.

Home test kits: These use the same immunoassay technology as most initial employer screenings. They're affordable and reasonably accurate for determining if you're above or below the standard 50 ng/mL threshold. A faint line is still a negative result.

Ultimately, the best approach is informed decision-making. Know when testing is likely, understand your personal risk profile, and plan accordingly.