Some useful information...........

From Lab Corp....



Additional Information
A positive test for cannabinoids indicates the presence of cannabinoid metabolites, 11-nor-9-carboxy-delta-9-THC is the major one (carboxy THC), in urine but is not related to source, time of exposure, amount, or impairment. Unless the test is confirmed by GC/MS, a positive result is presumptive and an unconfirmed test should not be used in workplace drug testing programs. Urine may contain carboxy THC for a week or 10 days after light or moderate use and as long as a month to 6 weeks after heavy use. Rapid storage of THC metabolites in body fat occurs after use. These substances are then released from storage sites slowly over time.


Cannabinoid:Creatinine Ratio, Urine

Use
Cannabinoid concentration is normalized using creatinine to correct for diurnal fluctuations in fluid intake and urine output. The normalized cannabinoid concentration can be used to monitor compliance with drug treatment programs. Serial determinations should be done at 2- to 3-day intervals. A 50% increase over the previous result is strong indication of continued marijuana use.