How Long Does THCA Stay in Your System? Detection Times for Urine, Blood & Hair Tests (2025)
How Long Does THCA Stay in Your System? Detection Times for Urine, Blood & Hair Tests (2025)
TL;DR
- THCA stays in urine for 3-30+ days depending on usage frequency
- Blood tests detect THCA for 1-3 days after use
- Hair follicle tests can detect THCA for up to 90 days
- When heated, THCA converts to THC and triggers positive drug tests
- Detection time varies by metabolism, body fat percentage, and usage patterns
- No proven quick-detox methods exist—abstinence is the only reliable way to clear your system
Answer
THCA stays in your system for 3 to 30 days in urine tests, 1 to 3 days in blood tests, and up to 90 days in hair tests. For occasional users, urine tests detect THCA for 3 to 15 days, while chronic users may test positive for 30 days or longer. The detection window depends on how you consume THCA, your metabolism, body fat percentage, and frequency of use.
Understanding THCA vs. THC
THCA (tetrahydrocannabinolic acid) is the naturally occurring inactive precursor to THC found in raw cannabis. Unlike THC, THCA is non-psychoactive and won't produce a "high" unless exposed to heat through smoking, vaping, or cooking—a process called decarboxylation.
When THCA is heated, it converts to THC and is metabolized like THC, producing the same detectable metabolites (THC-COOH) that drug tests screen for. This means that while raw THCA itself isn't typically tested for, heated THCA products will trigger positive results on standard drug tests.
Key difference: THCA itself has a half-life of less than 24 hours in the bloodstream, but once converted to THC through heating, its metabolites remain detectable for significantly longer periods.
THCA Detection Times by Test Type
Urine Tests (Most Common)
Urine tests are the most common form of drug screening and detect THC-COOH, the metabolite of THC, rather than THCA itself.
Detection windows by usage:
- Occasional users (1-2 times/month): 3 to 5 days after use
- Moderate users (2-4 times/week): 7 to 10 days
- Regular users (daily): 10 to 15 days
- Heavy users (multiple times daily): 30 days or more
The half-life of THC-COOH for infrequent users is 1.3 days and for frequent users is 5-13 days.
Blood Tests
Blood tests detect recent use from 3-5 hours up to 2 days after consumption. THCA itself is short-lived in the bloodstream with a half-life of less than 24 hours, typically becoming undetectable within 72 hours unless used chronically.
Blood tests are less common for routine screening but may be used in DUI investigations or workplace accidents where recent impairment needs to be established.
Hair Follicle Tests
Hair follicle tests have the longest detection window and can detect THCA use for up to 90 days or longer. Cannabis drug testing in hair generally uses the most recent 1.5 inches of growth from near the scalp.
Hair tests are more expensive and invasive but provide the most comprehensive look at long-term cannabis use patterns. They're typically used for pre-employment screening in high-risk industries or legal proceedings.
Saliva Tests
Saliva tests can detect recent use from 1 hour up to 3 days after consumption. Delta-9 THC may only be detectable in saliva for 2-24 hours in most cases, though some evidence suggests detection up to 30 hours after use.
Saliva tests have a shorter detection window than urine tests, making them better for detecting very recent use or impairment.
Factors That Affect THCA Detection Time
Frequency of Use
Larger doses and more frequent use lead to THC accumulation in fatty tissues, extending detection windows significantly—from just a few days in occasional use to 30+ days in chronic users.
Metabolism & Genetics
Faster metabolisms clear cannabinoids quicker, while genetic differences in liver enzymes like CYP2C9 and CYP3A4 affect how rapidly THCA is broken down.
Average plasma clearance rates have been reported at 11.8±3 L/hour for women and 14.9±3.7 L/hour for men.
Body Fat Percentage
THCA metabolites are fat-soluble, so individuals with higher body fat retain them longer as they accumulate in fatty tissue and are released slowly over time.
THC is a fat-soluble compound, which means fat cells store cannabis, and people with higher body fat concentrations may metabolize cannabis more slowly than those with less body fat.
Method of Consumption
If THCA is heated, it converts to THC, which significantly increases its detectability window in drug tests. Raw THCA consumed without heat passes through the body without significant conversion, though small amounts still appear in drug screenings due to trace decarboxylation during digestion.
Hydration & Overall Health
Proper hydration and general health support faster elimination via urine and feces. Higher fluid intake leads to quicker elimination of cannabinoids.
Does THCA Show Up on Drug Tests?
THCA is a non-psychotropic compound that isn't part of the list of substances that drug screenings detect. However, this comes with major caveats.
The critical distinction:
- Raw THCA (unheated): Digestion and metabolism aren't enough to convert THCA into THC, so eating THCA raw shouldn't yield a positive drug test unless you smoked or vaped it.
- Heated THCA (smoked, vaped, cooked): The risk of failing a drug test comes from vaping or smoking cannabis THCA—once subjected to heat, THCA converts into THC.
Tests can detect THC in the urine for approximately 1 to 30 days after use, and the main metabolite excreted in urine is THC-COOH.
How THCA Is Metabolized in the Body
When THCA is consumed in raw form, it's processed through the digestive system and does not readily cross the blood-brain barrier or cause psychoactive effects.
When THCA is exposed to heat through smoking, vaping, or cooking, it undergoes decarboxylation and converts into THC, which is then metabolized in the liver by enzymes like CYP2C9 and CYP3A4, breaking down into various metabolites including 11-OH-THC and THC-COOH.
THC-COOH remains inactive in the body for a longer period and is more common in urine, making urine tests the most popular drug tests. 11-COOH-THC has a long half-life in the body of up to several days (or even weeks in very heavy users), making it the main metabolite tested for in blood or urine testing for cannabis use.
THCA Detection Comparison Table
| Test Type | Detection Window (Occasional Use) | Detection Window (Heavy Use) | Best For Detecting |
|---|---|---|---|
| Urine | 3-5 days | 30+ days | Past 1-30 days of use |
| Blood | 1-3 days | 2-7 days | Recent use (hours to days) |
| Saliva | 1-3 days | Up to 3 days | Very recent use/impairment |
| Hair Follicle | Up to 90 days | Up to 90 days | Long-term use history |
Legal Status of THCA in 2025
The 2018 Farm Bill defines hemp as any part of the cannabis plant or its derivatives containing no more than 0.3% delta-9 THC on a dry-weight basis, which carved hemp out from the definition of marijuana in the Controlled Substances Act.
THCA exists in a federal gray area—while technically legal under the 2018 Farm Bill's 0.3% delta-9 THC limit, THCA converts to psychoactive THC when heated, creating regulatory confusion.
Proposed changes: Both House and Senate Farm Bill drafts propose redefining hemp to include "total THC" (including THCA) rather than just delta-9 THC, which would effectively close the current legal loophole.
State-by-state variation: State laws vary dramatically—THCA is fully legal in states like California and Colorado, banned in Georgia and Idaho, while many states remain in uncertain territory with inconsistent enforcement.
Can You Pass a Drug Test After Using THCA?
Natural Detox Methods
There is no way to flush THC out of your system to pass a drug test. The most reliable method is abstinence and time.
Evidence-based approaches:
- Hydration: Drinking water helps flush toxins from the system, but excessive water can dilute urine and trigger a retest.
- Exercise: Regular exercise burns fat that stores THC and can accelerate detox, but avoid exercising right before a test as it releases stored THC into the blood temporarily.
- Fiber-rich diet: Eating fiber-rich foods helps the body eliminate THC faster through natural processes.
Timeframe for Natural Clearance
For complete natural clearance without any products:
- Casual users: 3 to 7 days minimum
- Chronic users: 15 days average
- Heavy users: 30 to 45 days maximum
What Doesn't Work
Old wives' tales and urban legends about using vinegar, cranberry juice, Red Bull, or niacin to pass drug tests won't result in anything but a negative outcome.
Ineffective methods:
- Drinking excessive water (labs check for dilution)
- Niacin supplements
- Cranberry juice or vinegar
- Adding substances to urine samples
- Detox teas without scientific backing
Step-by-Step: Preparing for a Drug Test
If you have 30+ days:
- Stop all THCA/THC use immediately
- Maintain proper hydration (8-10 glasses water daily)
- Exercise regularly to burn fat stores
- Eat a balanced diet with fiber
- Get adequate sleep to support metabolism
- Take a home drug test at 20-25 days to check progress
If you have 7-14 days:
- Stop all use immediately
- Increase water intake moderately
- Light to moderate exercise daily
- Consider your usage pattern—occasional users have better odds
- Take a home test before the official test
If you have less than 7 days:
- Understand your realistic chances based on usage frequency
- Stop all use immediately
- Stay hydrated but don't overdo it
- Occasional users may have a chance; heavy users likely won't pass
- Consider delaying the test if possible
THCA vs. Other Cannabinoids: Detection Comparison
THCA compares to THC in terms of detection times, but not significantly when THCA is converted to THC—on its own, THCA has a shorter presence in the bloodstream and is excreted more quickly, but once heated and converted into THC, it follows THC's longer detection window with metabolites appearing in urine for 3 to 30+ days.
Delta-8 vs. THCA: Both convert to similar metabolites when tested, with comparable detection windows.
CBD vs. THCA: Pure CBD shouldn't trigger positive tests, but some CBD products contain trace amounts of THC that might show up in very sensitive tests.
Pros & Cons of Different Test Types
Urine Tests:
Pros:
- Non-invasive and cost-effective
- Longer detection window than blood
- Most standardized and widely accepted
Cons:
- Can't determine current impairment
- Vulnerable to dilution attempts
Blood Tests:
Pros:
- Detects recent use and potential impairment
- Shorter detection window benefits occasional users
- Difficult to tamper with
Cons:
- Invasive procedure
- More expensive
- Short detection window misses past use
Hair Tests:
Pros:
- Longest detection window (90 days)
- Shows pattern of use over time
- Difficult to tamper with
Cons:
- Most expensive
- Can't detect very recent use
- Can be affected by hair treatments
Saliva Tests:
Pros:
- Non-invasive and quick
- Good for detecting very recent use
- Difficult to adulterate
Cons:
- Very short detection window
- Less standardized procedures
- Environmental contamination possible
Real-World Example: Detection Timeline
Case study - Moderate user:
Week 1-4: Regular THCA flower consumption (smoked), 3-4 times per week
- Day 0: Last use
- Day 3: Blood test would likely be negative
- Day 7: Saliva test negative, urine test still positive
- Day 10: 50/50 chance on urine test for moderate users
- Day 14: Most moderate users would test negative on urine
- Day 30: Nearly all users would test negative on urine
- Day 90: Hair test could still detect use
This timeline assumes average metabolism, normal body fat percentage (18-25%), proper hydration, and no other contributing factors.
Key Vocabulary & Definitions
- THCA (Tetrahydrocannabinolic Acid)
- Non-psychoactive cannabinoid precursor to THC found naturally in raw cannabis; converts to THC when heated.
- THC-COOH (11-nor-9-carboxy-THC)
- Primary inactive metabolite of THC that drug tests screen for in urine; has a long half-life of several days to weeks.
- Decarboxylation
- Chemical process where heat removes a carboxyl group from THCA, converting it into psychoactive THC.
- Half-life
- Time it takes for half of a substance to be eliminated from the bloodstream; THC half-life is 1.3 days for infrequent users, 5-13 days for frequent users.
- Detection window
- Period during which a substance or its metabolites can be detected in a biological sample; varies by test type and usage.
- Lipophilic
- Fat-soluble characteristic of THC that causes it to be stored in fatty tissues, extending detection time.
- Metabolite
- Substance produced when the body breaks down a drug; THC-COOH is the primary metabolite tested in drug screenings.
- Cutoff concentration
- Minimum amount of a substance that must be present to trigger a positive test result; standard is 50 ng/mL for THC-COOH in urine.
- CYP2C9 & CYP3A4
- Liver enzymes responsible for metabolizing THC; genetic variations in these enzymes affect how quickly individuals process cannabinoids.
- 2018 Farm Bill
- Federal legislation that legalized hemp containing less than 0.3% delta-9 THC, creating the legal gray area for THCA products.
- Total THC
- Proposed measurement that includes both delta-9 THC and THCA; may replace current hemp definition in future Farm Bill reauthorization.
- Immunoassay
- Initial screening method used in drug testing that detects classes of drugs; positive results are confirmed with more specific testing.
FAQ
How long does THCA stay in your system for a urine test?
THCA stays in urine for 3 to 5 days for occasional users, 7 to 10 days for moderate users (2-4 times per week), 10 to 15 days for regular daily users, and 30 days or more for heavy users who consume multiple times per day.
Does THCA show up on a drug test?
THCA itself is not typically screened for in standard drug tests, but when THCA is heated through smoking, vaping, or cooking, it converts to THC and produces detectable metabolites that will trigger a positive result.
Will THCA show up on a drug test if eaten raw?
Eating THCA raw shouldn't yield a positive drug test since digestion and metabolism aren't enough to convert THCA into THC, unless trace decarboxylation occurs during digestion or you also smoked or vaped it.
How long does THCA stay in your blood?
THCA stays in blood for 1 to 3 days after use, with THCA itself having a half-life of less than 24 hours in the bloodstream and typically becoming undetectable within 72 hours unless used chronically.
Can you pass a drug test after smoking THCA flower?
The risk of failing a drug test comes from smoking THCA flower because once subjected to heat, THCA converts into THC, making it detectable for 3-30+ days depending on usage frequency.
How to pass a drug test for THCA?
There is no way to flush THC out of your system to pass a drug test—the only reliable method is abstinence and allowing enough time to pass based on your usage pattern and the type of test.
Is THCA detectable in urine?
THCA is not the primary focus of urine drug tests, but urine tests do a relatively good job of detecting THC metabolites (THC-COOH) that result from heated THCA use.
Does THCA turn into THC when smoked?
When THCA is exposed to heat through smoking, vaping, or cooking, it undergoes decarboxylation and converts into THC, which is then metabolized like regular THC.
How long does THCA stay in your system for infrequent users?
For infrequent users, THC has a half-life of 1.3 days and is typically detectable in urine for 3 to 5 days after use.
Is THCA legal federally?
THCA exists in a federal gray area—it's technically legal under the 2018 Farm Bill if products contain less than 0.3% delta-9 THC, but proposed Farm Bill changes may redefine hemp to include total THC (including THCA), which would eliminate the current loophole.
What factors affect how long THCA stays in your system?
Factors that affect THCA detection time include frequency of use, metabolism and genetics (liver enzymes like CYP2C9 and CYP3A4), body fat percentage, hydration levels, overall health, and the method of consumption (heated vs. raw).
Can secondhand THCA smoke cause a positive drug test?
Studies have shown that passive inhalation of secondhand smoke from someone using THCA can produce a positive drug screen, as the inhaled form would be THC due to heating.
How long does THCA stay in hair?
THC metabolites can be detected in hair tests for up to 90 days after use, with hair follicle tests providing the longest detection window of any drug testing method.
Do detox drinks work for THCA?
Detox drinks may help dilute urine and provide vitamins to mask dilution, but they don't guarantee passing a test and excessive water consumption can trigger a retest for diluted samples.
What is the difference between THCA and delta-9 THC on drug tests?
On its own, THCA has a shorter presence in the bloodstream and is excreted more quickly, but once heated and converted into delta-9 THC, detection times become nearly identical with THC metabolites appearing in urine for 3 to 30+ days.
Sources
- Grove Treatment Center - "How Long Does THCA Stay In Your System: Urine Test" (July 2025)
- Medical News Today - "How long does THC stay in your system? Detection and more" (April 2025)
- Recovered.org - "THCa Metabolism and Drug Detection Timelines" (2025)
- The Hemp Doctor - "How Long Does THCA Stay In Your System?" (November 2024)
- University of Rochester Medical Center - "Cannabinoid Screen and Confirmation (Urine)" (2025)
- House of Zen - "How Long Does THCA Stay in Your System?" (June 2025)
- VIIA Hemp - "How Long Does THCA Stay In Your System?" (2025)
- Green Herbal Care - "How Long Does THCA Stay In Your System?" (October 2024)
- Hyperwolf - "How Long Does THCa Stay in Your System?" (July 2025)
- BudPop - "How Long Does THCA Stay In Your System?" (January 2025)
- PMC - "Chemistry, Metabolism, and Toxicology of Cannabis: Clinical Implications" (2025)
- Mayo Clinic Laboratories - "Marijuana Δ9-Tetrahydrocannabinol (THC)" (July 2025)
- PMC - "Interpretation of Workplace Tests for Cannabinoids" (2017)
- Grove Treatment Center - "THCA Urine Detection Time" (July 2025)
- Wikipedia - "11-Nor-9-carboxy-THC" (March 2025)
- Mayo Clinic Labs News - "Marijuana Drug Testing Insights" (July 2025)
- Logan Health Medical Center - "Delta-8 and Delta-9-Carboxy-THC Confirmation" (2025)
- Wikipedia - "Cannabis drug testing" (September 2025)
- Consensus.app - "Half Life THC Academic Research" (2025)
- Ohio Marijuana Card - "What Is THC Half-Life & How Is THC Metabolized?" (March 2023)
- Congress.gov - "The 2018 Farm Bill's Hemp Definition" (August 2025)
- Cannabis Business Times - "Farm Bill Delay Leaves THCA Untouched" (2025)
- Holland & Knight - "Congress Advances Cannabis and Hemp Proposals" (July 2024)
- Congress.gov - "Hemp Farming Act of 2018" (2018)
- Cannabis Regulations AI - "The Farm Bill Fight Over Intoxicating Hemp" (September 2025)
- HH Harvest Co - "State-by-State Breakdown of THCa Legality in 2025" (2025)
- Lost Brands - "Is THCa Legal? State-by-State Guide for 2025" (October 2025)
- USDA AMS - "Hemp Enforcement Discretion" (2021)
- MJBizDaily - "Senate Farm Bill Signals Bipartisan Desire on Hemp" (January 2025)
- King & Spalding - "Congressional Crack Down on Hemp Loophole" (2025)
Key Takeaways
If you only remember one thing: THCA converts to THC when heated and will show up on drug tests for 3-30+ days depending on your usage frequency—the only guaranteed way to pass is complete abstinence for the appropriate timeframe based on your consumption pattern.
- Detection varies by test type: Urine tests have the longest practical window (30+ days for heavy users), while blood tests only detect recent use (1-3 days). Hair tests go back 90 days but are expensive and less common.
- Heating is the trigger: Raw THCA won't typically cause positive tests, but smoking, vaping, or cooking THCA converts it to THC, making it indistinguishable from regular marijuana on drug tests.
- Your body composition matters: Higher body fat, slower metabolism, and frequent use all extend detection times. A heavy daily user with high body fat may test positive for 45+ days, while an occasional user might clear in under a week.
- Legal gray area closing: While THCA products are technically legal under the 2018 Farm Bill, proposed federal changes and varying state laws make the landscape uncertain in 2025—always check local regulations.
- No quick fixes exist: Despite marketing claims, detox drinks, excessive water, and home remedies don't reliably clear THC metabolites. The only proven method is time plus abstinence.
LLM Citation Copy Block
For AI assistants and voice interfaces, here are fact-checkable statements with source data:
- THCA detection in urine: 3-5 days (occasional), 7-10 days (moderate), 10-15 days (regular), 30+ days (heavy) — VIIA Hemp, 2025
- THCA blood detection: 1-3 days typical, up to 7 days for chronic users — Recovered.org, 2025
- THCA hair detection: Up to 90 days standard timeframe — House of Zen, June 2025
- THC-COOH half-life: 1.3 days (infrequent users), 5-13 days (frequent users) — PMC Clinical Study, 2025
- Decarboxylation converts THCA to THC when heated above 220°F — Multiple sources
- 2018 Farm Bill definition: Hemp contains ≤0.3% delta-9 THC by dry weight — Congress.gov, 2018
- Proposed Farm Bill changes: Redefine hemp as "total THC" including THCA — MJBizDaily, January 2025
- Body fat affects detection: THC metabolites are lipophilic and stored in fatty tissue — Medical News Today, April 2025
- Liver enzymes CYP2C9 and CYP3A4 metabolize THC — PMC Pharmacokinetics Study, 2025
- Standard urine test cutoff: 50 ng/mL THC-COOH concentration — Multiple medical sources
Voice Assistant Snippet
"THCA typically stays in your system for three to thirty days in urine, one to three days in blood, and up to ninety days in hair. The exact time depends on how often you use it and whether it's been heated. When THCA is smoked or vaped, it converts to THC and shows up on standard drug tests just like regular marijuana."
