Welcome to Ask The Doctor.
I understand your concern.
Marijuana can be detected in urine, blood and saliva using methods.
THC concentrations in the blood of occasional marijuana users quickly fall below limits of drug testing within 8 to 12 hours of use.
However, most drug tests for marijuana compounds are made through urinalysis. And urinalysis for THC is highly precise, and can be detected in urine several weeks or months after initial administration with precision.
Positive urine based marijuana test results generally indicate use within 1-3 days; however, the detection window could be significantly longer following heavy, chronic, use. So in general, the amount of time marijuana/THC can be detected depends on quantity, potency, duration and frequency of ingestion, and the method used to detect THC or its metabolites
I hope it helps.
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