Every drug has its own unique half life which can be used to determine if a person has ingested the substance recently. Whether illicit or legally prescribed, a drugs half life is the amount of time which is required for the trace concentration of a drug within the red blood cells to be reduced by one half. Simply put, a half life is the duration of time it takes for half the amount of a drug to leave the body. Heavy or consistent substance abuse will increase the half life of the drug while infrequent users will expel the toxins from their body at a faster rate.
Half lives of the most commonly abused illicit drugs follows: Regular marijuana users retain a half life of 10 days while sporadic users have a THC life cycle (the active and traceable component in marijuana) of only 2 days. The half lives of Methamphetamines are 15-20 hours while cocaine is between 1-2 hours.
The half lives of the most commonly abused prescription drugs follows: The painkiller opiates, such as Vicodin, hydrocodone, hydrocodeine, oxycontin, Percocet, and oxycodone all have a half life between 4 and 6 hours. Anti-anxiety benzodiazepines such as Xanax and Valium have a time frame between 14-18 hours. Drug testing for most pills ingested needs to occur quickly after consumption due to the bodies rapid rate of expulsion for most commonly prescribed drugs.
Understanding the differences between the half lives of drugs is essential when determining the best method for drug testing. Urinalysis and urine test strips work best for drugs with longer lives such as marijuana and opiates while hair follicle tests and saliva drug tests will still show traces of drug use amongst quickly expelled drugs such as cocaine and methamphetamine. When trying to uncover and stop substance use and abuse, considering the half lives of each drug will enable you to find the most precise drug testing kit for accurate results unique to your situation.