November 5


Does Weed Go Bad? Learn What Actually Happens Here

By Great Canadian Herb

November 5, 2021

If you've ever smoked weed regularly, you've likely experienced the joys that come with finding a random bag hiding somewhere in your house. All fine and dandy, but understandably, you may have some concerns about smoking it.

Does weed go bad? Is it still safe to smoke after an extended period of time? What is marijuana's shelf life anyways?

We're here to answer all that and more. In this article, we'll cover the basics of how to store your weed, so it keeps fresh for longer, its average shelf life, and other factors that can affect its quality.

Can you get sick from smoking old weed?

Smoking weed that's past its prime isn't going to get you sick like eating a week-old piece of chicken is.

In this case, cannabis differs from food. When food goes bad, it becomes dangerous to eat. This is from the bacteria thriving in the organic compounds that make up the food we eat.

The same bacteria that affect the decomposition of food does not apply to cannabis.

Cannabis generally undergoes a curing and drying stage, which occurs over some time. This helps control the moisture content, leaving less room for bacteria and mould to grow, and also helps to increase the potency.

While your old weed may taste a little funny or smell off and not have as much of a kick to it, it's probably safe to smoke.

The dangers of smoking mouldy weed

While smoking weed that has mould on it won't always lead to severe consequences, in some cases, it can be very serious - especially in those with weakened immune systems.

Certain fungi, particularly Aspergillus, Mucor, and Cryptococcus, can cause severe and sometimes deadly lung, central nervous system, and brain infections.

If you discover mould on your weed, don't chance it. Instead, immediately toss it and go buy some new bud.

Does weed go bad or expire?

Weed doesn't necessarily have an expiry date, but in many cases (especially if you're buying from legal sources), it might have a "best by" date.

This is the approximate time when your weed may start to lose what little moisture is in it and go a bit stale. It will also begin to lose its potency, flavour, and scent.

What happens to old weed?

The same thing that happens to any plant once it's been removed from its growing environment - it shrivels up, dries out, and slowly loses all of its goodness.

That doesn't mean it's bad, but it may not bring about the most pleasant experience when you use it or be anywhere near as strong.

In today's day and age, dispensaries have popped up everywhere - unless you're in a pinch, it might be worth it just to buy some new bud.

Old weed loses its cannabinoid potency over time

There are over a hundred different cannabinoids present in cannabis, with THC and CBD being the most prevalent.

Each strain of cannabis has varying levels of cannabinoids and terpenes. Over time, the presence of light, oxygen, and heat slowly act on your weed, and the cannabinoid content will change as a result.

One example of this is THC and CBN. As your cannabis ages, exposure to UV rays and heat slowly breaks down the THC compound. This, in turn, raises the CBN content of your cannabis, as CBN is a result of the degradation of THC.

CBN isn't psychoactive like THC is, however - at best, it might make you a bit sleepy. But this is one situation where your weed will not produce as much of a high if enough of the THC has broken down into CBN.

How to identify old weed

Marijuana kept in a sealed, airtight container away from direct heat and moisture can last for years and still be completely smokeable, if a bit harsh.

There are a few different ways to tell if your weed is old or safe to consume. Use this guide below to judge whether you're better off tossing it or lighting up.


You're likely familiar with the scent of good weed (and even bad weed) - old weed won't really have much of a scent at all to it. This is because as it ages, your cannabis loses not only cannabinoids but terpenes as well; these are directly responsible for its unique aroma and flavour.

Be aware of any mildew or musty scents, which could indicate that mould is beginning to form.


Know the differences between mould and trichomes. Mould grows over the trichomes, looks like white powder or dust, and is visible to the human eye. Breaking your buds up will also reveal mould in the centre of them.


Old weed will generally be like dust in your hands when you break it apart. When you break apart cannabis that is well cured and dried, it makes a 'snapping' noise, while old cannabis makes a cracking sound and has a very dry texture.


If all else fails and you're still not sure, light up a small amount. As long as you aren't smelling, tasting, or seeing mould, you should be good to go. Be prepared for it to be quite harsh, though, and burn your lungs and throat.

How should you store weed?

If you don't want to end up with dry, dusty old weed that barely ends up doing anything when you smoke it, then it's necessary to take some precautions when you're storing it.

Airtight container

Exposure to oxygen will break down the compounds in your weed, so make sure to store it in an airtight container.

Glass or plastic containers are an excellent option for this; just make sure that the container you put it in is not too large.

Dark or tinted containers are best, as they help to minimize exposure to light.

Away from heat and light

Excess heat and light will also likewise cause the faster breakdown of your buds; always store your weed in a cool, dark place.

A good example would be in a cupboard or closet. A bad example would be over the stove or near a window.

Keeping your weed around or below room temperature is optimal to retain freshness - between 60-68 degrees.

Away from moisture

If you improperly store your weed and it takes on excess moisture, mould formation is possible.

You absolutely do not want to be smoking mould, so ensure your cannabis is stored away from any moisture sources.

Additional storage tips

Want to spruce up your stash? Nowadays, there are all sorts of cool options online for storing your weed that won't break the bank.

If you're looking to keep your weed at its absolute freshest, you can consider investing in humidity packs - these will keep your weed at its prime for at least six months and keep the humidity level at between 60-65%.

Refrigerating or freezing your weed is not advised. This can cause condensation to form, which can lead to mould.

For larger amounts of weed, vacuum sealing is a great option. You can take out what you need for a short period of time and reseal it as required. However, keep in mind that you should still be storing your vacuum-sealed weed away from heat, light, and moisture.

Final thoughts on old weed

While not all hope is lost when it comes to old weed, you want to be using it before it becomes completely stale.

Smoking stale weed can be harsh on your throat and lungs, so try not to let this happen if at all possible.

When properly dried, cured and stored, your weed can stay smokeable for a very long time, years even.

Have you ever smoked old weed you've found lying around the house? How was it?

About the author

As consumers ourselves, we know how important it is to know exactly what it is we are putting in our bodies. Here at Great Canadian Herb you'll find cannabis and CBD education, reviews, buying advice, and much more. As cannabis enthusiasts, we have dedicated our time and resources to relay accurate, easy to understand information on everything in the Canadian cannabis industry.

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