Like foods, medications and other substances you ingest, drugs and alcohol must be processed by your body before they’re eliminated from your system. The effects of drugs may last for hours, days or weeks
depending on several factors:
The type of drug you take
The amount of the drug you use
The frequency of your drug use
Your general health
Your metabolic rate
Your gender
Your height and weight
The digestive organs, respiratory organs, liver and kidneys are involved in the metabolism or elimination of many of the drugs you take. Drugs can be detected in your body by testing your breath, blood, saliva, urine or hair.