Does weed expire? How to decide whether to puff or pass

does weed expire? timer over pot leaf

There’s truly nothing like enjoying fresh weed. The pungent and enticing aroma, the bright green hues, and the smooth smoke are simply exquisite. But not everyone is lucky enough to have bud straight from the source, leading some to wonder: does weed expire?

It’s pretty rare for marijuana to “go bad” like a carton of milk or last week’s leftovers. What’s more likely is that cannabis flower will degrade, becoming less potent due to the loss of active ingredients like cannabinoids and terpenes. However, it is possible for bud to develop mold, particularly in overly humid conditions.

Keeping weed fresh is all about storage. From the type of container to where you place your stash, several factors can affect the shelf life of your cannabis. If you want to keep your bud the best it can be, there are plenty of ways to do so.

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How long does cannabis stay fresh?

In the best conditions and with proper storage, cannabis can stay fresh for six months to a year or more. However, one wrong move could spell disaster for your beautiful buds.

The path to perfect cannabis begins just after harvest. Excess water escapes from buds in a drying period. Curing takes place after. Like a fine wine, properly-aged cannabis has a richer flavor and offers a more enjoyable experience.

During the dry and cure phases, moisture makes cannabis susceptible to mold. Mildew can spread quickly and ruin a crop if the environment is too humid and airflow is stagnant. Smoking moldy weed is extremely dangerous, especially for medical patients, and can lead to severe lung infections. This is the only time when the answer to “does weed expire” is a resounding “yes.”

Fortunately, once buds make it through the dry and cure stages, the risk of mold dwindles. Also, most licensed cannabis is tested for pathogens to ensure consumer safety. At that point, it’s more about potency and quality than pathogens.  

does weed expire woman holding bag
How long will the weed you picked up last? It all depends on storage Photo: Canva and GreenState

The best way to store your weed

Store cannabis in an airtight container in a cool, dark place. It should also be out of reach of children and pets, preferably in a locked cupboard or box.

Direct exposure to UV rays from the sun or bright lights can cause bud to lose potency. The THC will oxidize and turn into something called CBN. This cannabinoid is less psychoactive than THC, meaning you may not get the experience you were hoping for when lighting up that joint. 

Jars or containers that are opaque and kept out of the light are the best way to prevent oxidation. While many people like mason jars, they may not keep the UV rays away. 

Dry weed is also less than desirable. If left out or in a loose baggie or container, the air can cause bud to dry out. When this happens, the terpenes evaporate. These are the compounds responsible for the flavor, aroma, and overall effects of cannabis.

If terpenes disappear, cannabis is bland and less potent. Some people use two-way humidity control packs from Boveda or TerpLoc containers from Grove Bags to keep weed fresh and enjoyable for the long haul.

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What happens if you smoke old weed?

Smoking old weed is not always dangerous, but it can be a less-than-stellar experience. There are ways to help prolong the shelf life of your bud, but it will eventually degrade over time. 

According to research, weed loses roughly 16 percent of its THC after one year. As mentioned above, the THC is turning into CBN. CBN may give you a bit of a buzz, but it’s nowhere near as strong as THC.

However, CBN has become more popular thanks to its perceived ability to promote sleep. CBN gummies have exploded in the marketplace, but most people who buy weed seek THC—not CBN.

In rarer cases, old weed may develop mold, especially in humid conditions. This is more serious since inhaling mold spores can have serious consequences. You should never smoke bud that looks suspect—it’s just not worth the risk.

does weed expire
Can smoking old weed be harmful to your health? Photo: Canva and GreenState

Ways to use old weed

If you have bud lying around that is still in smokable condition, there are plenty of ways to ensure it doesn’t go to waste. There’s still THC in there, after all!

Many people opt to make canna-butter or oil with their old stash. Edibles such as weed cake, brownies, or gummies are relatively easy to whip up. Eating weed often leads to a much more powerful high than smoking, so you should always follow edibles dosing recommendations before popping another piece of canna-pie in your mouth.

If edibles aren’t your thing, you can also craft infused topicals using coconut oil or shea butter. THC lotions, salves, and balms can be great for aching muscles or itchy skin. They also lack the overt psychoactive effects that come from other consumption methods. Topicals also have a long shelf life, meaning you never need to ask “does weed expire” with these products.

For people who love to dab, DIY concentrates can be made with old bud. All you need is some parchment paper and a hair straightener. Place nugs inside the paper, fold in half, then squish them between a hot hair straightener. Oil called rosin will ooze out, which can be scraped off the paper and enjoyed.

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Proper storage of other cannabis products

Keep cannabis-infused edibles, vape pens, and concentrates in airtight containers away from kids and pets (just like bud). It’s also crucial to stay away from sunlight and overly warm temperatures.

Edibles and extracts may do best in the refrigerator. Make sure to read the label to discover recommendations. For example, drinks may need to be kept cold after opening.

Keep vape carts and pens in an upright position. This helps prevent clogs or leaks. 

Does weed expire?

When stored properly in a cool, dry place out of direct light, cannabis can easily last up to a year or more. It may lose potency over time, but it’s still smokable. All regulated weed products have expiration dates listed on them, but it’s typically more of a suggestion than a rule for anything that’s not edible. 

Smoking older bud may not offer as much kick as when fresh, but it likely won’t hurt you. Discard any moldy weed, but feel free to get creative with a stash past its prime—there’s still plenty of juice for the squeeze.


rachelle gordon

Rachelle Gordon is a cannabis journalist, Emerald Cup judge, Budist critic, and editor of She began her weed writing journey in 2015 and has been featured in High Times, CannabisNow, Beard Bros, MG, Skunk, and many others. Rachelle currently splits her time between Minneapolis and Oakland; her favorite cannabis cultivars include Silver Haze and Tangie. Follow Rachelle on Instagram @rachellethewriter