How Long Do Drugs Stay in Your System? (Complete Guide)
Understanding how long drugs stay in your system is important for medical, legal, and workplace reasons. Detection times vary depending on the type of drug, frequency of use, metabolism, and the type of drug test being used. Some substances may clear the body within hours, while others can remain detectable for weeks or even months.
In this guide, we break down the most common drugs and explain how long they can typically be detected in urine, saliva, and hair tests.
Cannabis (THC)
Cannabis is one of the most commonly tested substances. THC is stored in fat cells, which means it can stay in the body longer than many other drugs.
- Urine: 3 to 30+ days (heavy users may test positive longer)
- Saliva: 24–72 hours
- Hair: Up to 90 days
Frequent use significantly
increases detection time.
Cocaine
Cocaine is a fast-acting stimulant, but it still leaves behind metabolites that can be detected for several days.
- Urine: 2 to 4 days
- Saliva: 1 to 2 days
- Hair: Up to 90 days
Occasional use clears faster, while repeated use may extend detection.
Opiates (Heroin, Codeine, Morphine)
Opiates vary depending on the type and dose.
- Urine: 2 to 3 days
- Saliva: 24–48 hours
- Hair: Up to 90 days
Prescription opiates may be detectable longer in frequent users.
Amphetamines
This includes drugs like speed and some prescription stimulants.
- Urine: 1 to 3 days
- Saliva: 1 to 2 days
- Hair: Up to 90 days
Benzodiazepines (Diazepam, etc.)
These are sedatives often prescribed for anxiety and sleep issues.
- Urine: 3 to 7 days (longer for chronic use)
- Saliva: 1 to 3 days
- Hair: Up to 90 days
Long-acting benzodiazepines may remain detectable for weeks.
Urine vs Hair vs Saliva Testing
Urine Tests
Most commonly used. They detect recent use and are cost-effective.
Saliva Tests
Best for detecting very recent drug use (within hours to a few days).
Hair Tests
Provide the longest detection window, often up to 90 days, showing long-term patterns of use.
- Cannabis (THC)
- Cocaine
- Opiates (Heroin, Codeine, Morphine)
- Amphetamines
- Benzodiazepines (Diazepam, etc.)
Factors That Affect Detection Time
Several factors influence how long drugs stay in your system:
- Metabolism speed
- Body fat percentage
- Frequency of use
- Age and overall health
- Hydration levels
- Type and potency of drug
Final Thoughts
Drug detection times are not the same for everyone. While some substances leave the body quickly, others can remain for weeks depending on usage patterns. Understanding these timelines is essential for medical testing, employment screening, and legal requirements.
Why Choose Motor Medicals?
At Motor Medicals, we provide fast, reliable, and professional medical assessments including drug and alcohol screening services for drivers and occupational health requirements. Our tests are conducted in a confidential and professional environment, ensuring accurate results and quick turnaround times.
You can book your appointment online at https://motormedicals.com/booking/ or call us directly at 0161 241 9622. Our services start from £70 depending on the type of medical or screening required. We are committed to making the process simple, affordable, and efficient for all clients.
Book your Medical Today
Book your medical appointment with Motor Medicals today for fast, reliable, and professional service at an affordable price.
