Blood Drug Testing

Does a blood drug test show when you smoked marijuana?

Will a blood drug test show exactly how long ago someone smoked weed, or just if its in their system?

Public Comments

1. both.
2. it'll show how much thc (the main chemical and what gets u high in pot) is in ur system, and if its in it . it doesnt show how long ago just that its in there and how much
3. Any drug test will show if you have had marijuana
4. Marijuana will show up in a blood test. THC (Tetrahydrocannabinol) can stay in a person's body for as long as 3 to 90 days after smoking or being ingested orally. There are numerous determining factors for how long drug toxins stay in a persons body which vary from person to person, such as the analytical method used, your health, your body weight, metabolism, fluid intake, the type of drug toxin, and the degree of exposure to the drug toxin. Delta-9-Tetrahydrocannabinol or THC, one of nearly 400 chemicals in a cannabis plant, accounts for most of marijuana's psychoactive, or mind-altering, effects. The strength of the drug is determined by the amount of THC it contains which varies from plant to plant. Marijuana stays in your system for different amounts of time depending on how often you smoke it, how much you smoke, and the makeup of the individual (weight/height/etc.).
5. Well, not exactly because of differences in metabolism. But it WILL show the active amount of thc rather than metabolites that just offer evidence it was consumed at one point. Blood marijuana tests are actually testing for thc. Thc is generally out of the blood (and no longer impairing you) after several hours. People who use 24/7 can show active thc in the blood generally for 72 hours, but up to a week. If there is a question regarding current impairment, you should go with blood or saliva. Urine tests, on the other hand, are looking for thc-cooh, which is the metabolite produced when the thc is broken down. The metabolites are NOT psycho active. They can be detected anywhere from a few days (occasional only use) to several weeks (at least 4, some sources even say 8... for the 24/7 users). The metabolites are detectable for so long because they are fat soluable... so they dissolve into the fat, and then slowly get deposited into the body's waste.