Richard S. Gubbe
Sep 23 2019 . 3 min read

Stale Mate

Stale Mate

Can cannabis go bad?

Can cannabis go bad?

How often should you turn over a new leaf? Or less philosophically and more practically: Can cannabis go bad? When that question arises, there are multiple answers: Cannabis will slowly deteriorate over time, but how it was dried and how it was kept have a lot to do with longevity of THC in that strain and how quickly it transforms into another cannabinoid, although a non-psychoactive one, called CBN or cannabinol.

From the moment a cannabis plant is plucked from 

the soil, degradation begins. How quickly can depend 

on both the grower and the consumer. The simple answer 

is cannabis doesn’t “go bad” over time, but freshness 

and proper storage can lead to a sustained high with less throat irritation.

The plant begins to dry and decay the moment of harvest, though it can take a month before actually hitting the shelves. The main culprit to be avoided is moisture that can lead to mold. Think about smoking mold and brain damage comes to mind. Molds can appear long after drying and packaging, so beware. Another key to longevity is storage away from UV rays or any other rays for that matter.

Keep an eye on your harvest date and/or packaging dates, as they can be the warning of THC degrading into CBN, but the clock ticks slowly, meaning it should be at least two months from packaging dates that partakers will see a noticeable shift in THC to CBN potency.


CBN occurs naturally as an oxidative degradation product of THC, formed when THC is exposed to UV light and oxygen over time. Unlike THC, CBN induces little to no intoxicating effects and exists only in small amounts. Patients who need to become relaxed or stay productive with a clear head may find CBN to be helpful, and products with high amounts are in the marketplace. Where cannabis tests in Nevada can exceed 25 to 30 percent for THC levels, CBN hovers around 1 percent or less.

CBN offers effects that are in the infantile stage of research but so far, so good in the early stages of charting benefits. CBN’s studied benefits include pain relief, an easing of insomnia symptoms, growth of bone cells, with additional antibacterial and anti-inflammatory properties. CBN also has been credited for serving as an anti-convulsive and an appetite stimulant.

THC oxidizes through exposure to oxygen when converting to CBN, even when sealed in a jar. Terpenes also begin to fade the same as perfume dissipates. But proper storage such as at a cool, dry room temperature and no exposure to sunlight helps keep flower fresh. One way to tell cannabis has transitioned is the flower is a lot harsher on the throat when smoked.

And those folk stories about getting way high on months-old weed found lying around could be that everyone was just happy to find some forgotten-about cannabis. The easiest solution is to keep rotating your stock, as they say—and stay as fresh as possible. Or just turn over a new leaf.