How Long Does Cannabis Stay in Your System?

Background of cannabis leaves and blood vial of blood with a label that shows a positive result for cannabis in blood test marked with a checkmark.

There are many reasons why someone would need to know the answer to this question: cannabis is, after all, a drug. There are potential interactions with other medications to consider, company drug tests that pop up unexpectedly. Sometimes the experience isn’t enjoyable, and you want to know when it’ll wear off. 

Or you might be wondering, “How long does weed stay in your bloodstream?” because you’re curious about the science of cannabis. 

Whatever you’re reasons, you’re in the right place to help shed light on this complicated issue. 

So, how long does cannabis stay in your system? The abridged version is: it depends on several factors—including whether your stash is stored with Boveda’s 2-Way Humidity Control packets

Allow us to elaborate. 

How Long Do the Effects of Cannabis Last?

Before tackling tough questions like “How long does cannabis stay in your system?” or “How long can THC show up in a urine test?” let’s approach the question from an effects standpoint. How long does THC continue to work its magic, activating cannabinoid receptors and altering the typical flow of information between your body and brain? In other words, how long do you feel ‘high’?

The answer depends on several variables like tolerance, metabolism, strain, and method of consumption. It also depends on whether you keep weed fresh since studies show that proper weed storage has a marked impact on long-term potency. Still, here are some generally agreed-upon time windows: 

  • Smoking or vaporizing: Starts within seconds or minutes of consumption and lasts for two to four hours. Effects typically peak around the 30-minute mark. 
  • Edibles: Starts a little later, between a half-hour to two hours after consumption; effects can last up to eight hours, typically tapering in intensity after the four-hour mark. 
  • Dabbing and concentrates: Kicks in immediately, lasting between an hour and three hours. 

There are other consumption methods—like topical application—but the above three are the most common. 

Cannabis leaf with a collage of test result numbers with vials of blood cells

How Long Is Cannabis Traceable in the System? Hair, Blood, Urine and Saliva

This one’s a little trickier to answer. It isn’t as simple as asking how long THC stays in the system; the question involves understanding toxicological processes. 

Traces of THC can turn up in several places. For instance, THC can be present in hair during its “anagen” cycle, when newly grown hair incorporates substances circulating in your bloodstream. It turns up in your urine when your body breaks the substance down into metabolites, subsequently filtered by the kidney and excreted via urine. Similarly, THC metabolites can catch a ride to your saliva via the bloodstream’s highway to the salivary glands. As much as we love cannabis, it isn’t a discreet houseguest—it leaves behind several footprints. 

What Make This Such A Tricky Question?

Asking, “How long does cannabis stay in your system?” is too general. It’s better to consider the various half-lives according to bodily products. Here’s the rough guide:

  • Saliva: THC doesn’t stick around very long in saliva – it’s present the same day and up to three days afterward. We looked for resources on whether swallowing more than usual could flush THC, but sadly, our research turned up a giant goose egg on that one. Sorry. 
  • Blood: Blood has a similarly short half-life, as THC courses through the veins for between two and 12 hours. However, according to this peer-reviewed study, it’s possible to test positive at the 30-day mark. 
  • Urine: This one’s interesting. A Mayo Clinic study found that THC detection time in urine was commensurate with use frequency. For single-time users, cannabis stuck around for three days; for moderate uses (about four times a week), the drug was detected for up to a week; and chronic daily users can hold traces of THC in their urine for 30 days. 
  • Hair: As mentioned, THC reaches hair in the anagen growth cycle. And it can stick around on hair for a while. Inverse reports that the drug remains for 90 days in hair, a timeline backed up by several other sources.  WebMD notes that “(THC metabolites) will stay there until you cut your hair.” 

It’s essential to note that these are averages reached in research settings. In a real-world setting, the statistical margins become less clear. In other words—results will vary.

What Does It All Mean?

Cannabis is legal in most states and entire countries. Its effects are well-known and broadly understood by the general public. So, what does all this discussion of effect and toxicology mean? 

It’s not an exact science, but cannabis WILL leave your system in time—how much time will depend from person to person, and the quality of their cannabis.

Regardless how long traces may be detected, if you’re smoking cannabis flower, it should be stored with Boveda 2-Way Humidity packs so it’s always fresh, and never stale or moldy. Properly stored cannabis retains the vital terpenes that make your cannabis flavorful and potent.

Learn more about the science of cannabis: explore Boveda’s Cannabis Blog.  And if you want to keep your bud fresh, sticky, and fluffy regardless of the climate, use Boveda 2-Way Humidity Control packs for Cannabis.


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