Does Weed go Bad? [Explained]


Picture the scene; you are rummaging through your house in the midst of a spring clean and come across some weed you had completely forgotten about. You’re not sure how long it has been there but you want to know if it is ‘safe’ to use it or if it has gone bad. The short answer to this query is ‘it depends on your definition of bad’. The precise longevity of marijuana depends on a variety of factors, including extraction method, processing and even the strain itself.

What Happens to Old Weed?

First and foremost, marijuana will not go ‘bad’ in the sense that it will cause harm to a user. However, its potency will dissipate over time and there is a chance that you’ll experience a woozy and relatively unpleasant high. As you probably know, marijuana contains hundreds of compounds, including over 100 identified cannabinoids. As it grows, it produces cannabigerolic acid (CBGA) which is synthesized into THCA, CBCA, or CBDA.

can weed go bad

Raw cannabis is unlikely to get you ‘high’ because it needs to be decarboxylated. This is the term given to the process of converting the marijuana’s biosynthetic acids into psychoactive and non-psychoactive substances such as CBD, CBN, and THC. One of the best-known and most important transformations is from THCA into THC – the most powerful psychoactive compound in weed.

Airtight Storage

One weed lover/scientist decided to find out exactly what happens to cannabis as it ages and sent a five-year-old sample into the Cannalysis testing lab. We already know that THC transforms into CBN when exposed to oxygen. CBN is known for its exceptional healing properties and is also a very effective sleep aid according to users. The sample in question was kept in a glass mason jar, so exposure to air was minimal. As a result, the weed’s THC content remained high, although the percentage of CBN also increased slightly.

In terms of aesthetics, the buds were less resplendent in terms of glimmer and color. When the buds were new, they were sticky, but after five years of airtight storage, they had become crunchier, although the trichomes were still in excellent condition. Rather surprisingly, the terpene content and scent remained strong, although the first whiff of the weed after opening the jar was awful!

The marijuana also had a different taste, with a dry and earthy flavor and a relatively harsh throat hit. Overall, weed that has been stored in an airtight container will still provide you with a decent experience after several years.

Improperly Stored

Depending on where the weed was stored, the bud will become damper or drier with age and will have an extremely high CBN count. If the weed is dry when you find it, you can safely smoke it, although you should prepare for very harsh hits. If the weed is damp, there is a chance it will develop mold, and trying to smoke moldy marijuana IS a health hazard. Incidentally, while the oldest known marijuana stash contained a high level of CBN, the 2,700-year old sample still contained a reasonable amount of THC; enough to get a novice user high at the very least!

Identifying Old Weed That May Be Past Its ‘Best Use’ Date

In summation, marijuana stored in an airtight container away from direct heat and also not kept in a damp location can last many years and remain perfectly usable. However, the weed you purchase isn’t always necessarily kept in such pristine conditions, so you have to know when someone is trying to sell you bad marijuana. Alternatively, if you find old weed and don’t know how long it has been hidden, you need to check these pointers to ensure you’re not using stale cannabis that is certain to have a nasty taste.


Excessively old and dried out weed will break apart into a fine powder with ease. While it may initially resemble kief, stale marijuana will also contain seeds and stems. You can identify mold fairly easily once you know what to look for. Check out the location of the offending substance’s concentration to determine whether it is mold or trichomes: Mold grows over trichomes and looks like a mass of white powder capable of penetrating every surface of the herb. You can also spot mold when you break apart the nugs.


Terpenes don’t last long on poorly stored weed. Therefore, if your cannabis offers a pleasant scent, it is almost certainly fit for consumption. Beware marijuana with a mildew-type smell, as this is a sign of possible mold growth. If you get a weird chemical aroma, it probably means that pesticides or other chemicals have been used to treat the weed while it grew.


Pulling apart the nugs should tell you everything you need to know about the condition of the weed.You can determine whether there is any moisture content or see if it falls apart in your hands. Herb that is well cured and dried will make a ‘snapping’ sound when you handle it, whereas old cannabis makes a cracking sound and also feels extremely dry.


If your marijuana passes all of the above tests, smoke a small amount to be 100% sure.One thing about ‘bad weed’ is that you will taste the problem almost immediately!

Preparing & Storing Your Marijuana for The Long-Term

Since we know that marijuana lasts a long time when stored correctly, it is wise to learn how to prepare and store your weed so it gives you years of pleasure. It is essential that the cannabis is properly cured and dried immediately after harvesting. This process breaks down chlorophyll and rewards you with a nice odor and flavor. It also boosts the cannabinoid profile, which means you get stronger and more effective marijuana. Furthermore, it reduces the likelihood of a rough smoking experience and decreases the risk of mold growth.

does weed go bad

Assuming you buy the weed from a dispensary, the curing and drying processes are already done for you. As a result, all you have to worry about is storage. Even basic adherence to long-term storage principles means your weed should last at least a year. To prevent weed from drying out too fast, make sure you avoid the following:

  • Storing it in a plastic bag.
  • Keeping it in a container that’s far too large.
  • Exposing it to excessive light or heat.

Poorly stored cannabis could dry out and become harsh to your lungs in a matter of days. If you are serious about keeping your marijuana fresh and are intent on purchasing a fairly large supply, consider investing in Humidity Packs. If you purchase one, you can keep your weed in an airtight glass jar in the humidity pack and expect it to remain fresh for at least six months. The pack keeps the humidity between 60% and 65%, but you have to keep the herb stored between 60 and 68 degrees Fahrenheit.

If you intend to store the marijuana for longer, vacuum seal it for ultimate freshness. While taking this step should help ensure the freshness of the weed for the long-term, make sure you store it at the right temperature and moisture while keeping it away from direct sunlight. Some users try to freeze their cannabis, but this isn’t a good idea because it is likely to become brittle once you remove it from cold storage.

Final Thoughts on “Does Weed Goes Bad?”

As long as marijuana is properly harvested, cured and dried, it can age well for a significantly long time, and smoking it is unlikely to cause any deleterious health effects. That said, it will probably taste awful and your lungs and throat will not thank for you for the extremely harsh smoke. And remember that if your cannabis is stored in a location exposed to excessive moisture, mold will grow and smoking such herb is likely to make you extremely ill.

Heat, light and moisture are the enemies of long-term marijuana storage, so if you want your weed to taste good months after purchasing it, store it in an airtight container in a cool, dark place. Over time, the potency of your cannabis will dwindle, but even though some of the THC will transform into CBN, you should still derive some medicinal benefits; although the ‘high’ will feel weird and not necessarily pleasant. At least one experiment found that weed stored in an airtight container for five years still tasted good and offered a nice, potent kick.

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