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Does Marijuana Go Bad? How to Keep it Fresh for Longer

By Last updated on April 30, 2024Last updated on April 30, 2024No Comments

Cannabis will not spoil in the way that food does. When food spoils or becomes rotten, it produces discoloration and has a terrible odor. This is because food is a breeding ground for bacteria and microorganisms. Weed, on the other hand, is not as susceptible to this.

After weed is harvested, it is dried and then cured. This process rids weed of any excess water and therefore stabilizes its moisture level, leaving the nugs less volatile than say a fresh, un-dried nug.

A living weed plant is vulnerable to what is called “bud rot.”  Bud rot is a fungal disease that lives best in cool, humid, temperate climates, and it attacks weed plants in all stages of life.

In regards to dried and cured weed, you do not run much risk of mold. The greater concern becomes losing potency when your weed gets too old. Storing your weed properly can help with this but regardless of storage conditions all bud eventually will degrade in quality.

does marijuana go bad

What happens to weed if it is old?

There are over 110 identified cannabinoids in cannabis, with THC and CBD the most abundant, followed by CBN. After weed has been harvested, dried, and cured, the presence of oxygen, light, and heat alters the cannabinoid structure slowly over time.

Cannabis produces cannabigerolic acid (CBGA) while it grows and matures. CBGA eventually synthesizes into CBCA, CBDA, and THCA. The cannabinoids that we frequently use, THC and CBD, are the results of THCA and CBDA becoming activated.

When THCA or THC becomes exposed to UV light and oxygen for a long period of time the compounds degrade to CBNA and CBN. While this may sound bad, CBN (cannabinol) actually has its own benefits. The only problem is that CBN does not produce psychoactive properties and therefore will not get you high.

CBN is very beneficial as a sedative. It provides relief throughout your mind and body leading to a state of relaxation and calmness.

When your weed becomes old it will lose its potent smell and will adopt a scent of hay or dead grass. The quality of smoke it provides will become harsh due to the fact that it has virtually no moisture remaining. It also loses its beautiful colors of gold, purple and vibrant green; often turning into a pale brownish-green.

When your weed is too old it is hard to miss. Just touching your nugs will tell you the story as it crumbles into dry pieces. Unlike food, you can still safely consume old weed but you should take smaller hits than usual or you will burn out your throat.

Old edibles

If you purchase weed edibles from a dispensary they should come with labels that list an expiration date. Much like regular food, cannabis-infused food can spoil rotten and become unsafe to eat. Certain edibles like gummies or hard candy should last for a very long time but other edibles like brownies, cake, and cookies can spoil because they contain dairy products.

Old concentrates

Older cannabis concentrates can alter in potency and flavor much like old flower. Concentrates are more difficult to tell if they have degraded in quality because they do not change in scent or appearance as weed flower does. The only way to know if your concentrates are old is if the psychoactive effects are not what they originally were.

Old vape pens

Vape pens with old cartridges change over time like other cannabis products. When the material in a vape cartridge gets old it becomes much more viscous. This may render it completely unusable because the cartridge material can no longer vaporize through the pen.

How long does weed stay fresh?

Dried and cured cannabis keeps for 6 months to 1 year if it is stored properly. Eventually, it will lose its potency and aroma. According to research, cannabis loses roughly 16 percent of its THC content after 1 year, and more in subsequent years:

  • 26 percent THC lost after 2 years
  • 34 percent THC lost after 3 years
  • 41 percent THC lost after 4 years

Is it dangerous to smoke old weed?

Old weed is not dangerous. The quality becomes poor and your high will not be nearly as strong as with fresher weed. If your weed is too wet and stored improperly then it can possibly develop mold which if smoked is potentially dangerous to the health of your lungs.

You can tell if your weed grows mold if it develops discoloration or becomes fuzzy much like mold on food.

Luckily, this is easy to monitor as long as you keep an eye on your stash and you open the jar often enough for moisture levels to stay at a safe range of 54 percent to 63 percent. A study done at the University of California, Davis found mold developing on 20 different weed samples that were purchased from dispensaries and licensed caregivers in Northern California.

Inhaling smoke or vapors from mold-contaminated weed could cause serious illness. So be vigilant in taking proper care of your stash.

How to keep weed fresh for longer

Each different cannabis product requires specific care in order to preserve its quality. Here is a breakdown for the following products:


You want to limit the exposure to light and air while maintaining a proper humidity level.

Store your weed in sealable jars such as Mason jars. If you can find brown tinted ones then these will be even more effective at blocking out as much light as possible. Store your jar somewhere cool and dark.

If you plan on keeping your weed for a while then you may want to get some humidity packs to throw in the jars. There are specifically designed humidity packs that are able to control the humidity level to around 60 percent.

You could also consider vacuum-sealing your weed. This not only blocks out air but also scent in case you plan on being discreet with your bud.

Do not put your weed in a freezer. Although mold cannot grow in a freezer, the cold conditions will make the trichomes on your bud brittle and they will fall off upon handling them. Remember, trichomes are resin glands on your weed that play a big part in the psychoactive properties.


Edibles, on the other hand, are great to store in the freezer. Make sure to wrap them up well to avoid possible freezer burn. Another good option is a refrigerator but they will last longer in the freezer.


The market is flooded with small containers designed specifically for concentrates. Silicon, glass, or plastic are all fine materials just make sure to keep them in a cool and dry place. If you plan to keep your concentrates for a while then consider getting a small, sealable glass jar.

The Sanctuary Editorial Team

Our writers use a combination of research and personal experiences to eloquently tackle these topics. The research process utilizes multiple levels of information. We reference informal channels for details relating to casual topics such as describing slang or how to create a bong out of fruit. We also examine scientific publishings for up-to-date research. The accuracy of our articles is crucially important to us and they are written with the idea of inclusiveness for readers of all walks of life.