The Grapevine

Can Weed Be Detected In Blood And Saliva Testing?

Marijuana usually stays detectable in the body for one to 30 days after last use, but daily use could keep the drug present for several months, with the longest period being more than 90 days.

How long marijuana stays in the system depends on the dose and how it was taken. Higher doses and more frequent use could lead to increased time for the body to eliminate the drug, according to Healthline

Age, gender and body mass index also contribute to how the body processes and metabolizes marijuana. There are many ways to detect marijuana in the system, but it is a common question how the drug may appear in blood or saliva tests. 

The answer is that weed stays detectable in the blood for one to two days, according to Therapeutic Drug Monitoring. It commonly takes just seconds of inhalation for marijuana to enter the bloodstream.  

Marijuana is distributed to tissues and reabsorbed in the blood and broken down. In some cases, due to chronic heavy use, marijuana appears in tests 25 days after last use. 

Saliva testing is another way to detect weed. A study in 2014 showed that weed remains detectable in oral fluids for one to three days if taken occasionally and up to 29 days for chronic users.  

Even not directly smoking marijuana could put the drug in the body because of second-hand smoke exposure. 

Hair strands can also be used to detect the use of marijuana. Hair testing can detect the traces of the drug in the system even up to 90 days after use. 

Marijuana can actually travel through small blood vessels and enter hair follicles when smoked or ingested. A 1.5-inch hair segment close to the scalp can provide a window of marijuana use for the past three months.

Edible marijuana products tend to keep the drug longer in the body than those taken via inhalation. 

Amid the growing interest in the legality of cannabis in the U.S., non-medical use of marijuana still remains illegal in some states. 

The District of Columbia and the states of Alaska, California, Colorado, Maine, Massachusetts, Michigan, Nevada, Oregon, Vermont and Washington have already adopted laws legalizing marijuana for recreational use.