Cannabis Science

How Long Do Shrooms Last?

man holding shrooms

Even though drugs like weed and shrooms don’t have an expiry date imprinted on them, they don’t last forever. If you were cleaning up one day and found a bag of magic mushrooms, you may be wondering whether or not they’re expired and what would happen if you used them. Let’s explore those concerns and answer the question, how long do shrooms last? 

Photo: Unsplash

Do Shrooms Go Bad?


The old adage that nothing lasts forever is true when it comes to magic mushrooms.

Your mushrooms may go bad due to time passing or bacterial and mold growth.

In terms of loss of potency, research shows shrooms lose potency over time. Therefore the old shrooms you found may not be worth the trouble.

How Long Do Shrooms Last?

A 2020 study that when stored in ideal conditions, the chemicals responsible for your trip decrease significantly after a month.

In 2022, Altitude Consulting conducted its own research to test how the potency of shrooms drops over 11 weeks. 

They specifically tracked baeocystin, psilocybin and psilocin.

They kept the mushrooms at room temperature and away from UV light. 

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After 11 weeks, 91.3% of the original psilocybin was retained while psilocin decreased by 32.2%. Finally, after the same period, only 0.1% of the original baeocytin remained.

So, what does that mean for you?

The researchers said, “if your mushrooms are 6 weeks old, you cannot simply blindly apply our data to your mushrooms. That being said, our data can and should be used as a guide.”

Signs of Spoilage

Unfortunately, bacteria and mold can grow on your magic mushrooms and at that point, you need to toss them. 

Not sure if your shrooms have gone bad?

According to Psychedelic Passage, here are signs of spoilage you should look out for:

  • Brown and black spots or abnormal coloring 
  • Sliminess on the surface of the mushroom
  • Foul odor
  • Excessive softness or squishiness
  • White, blue, or green fuzzy growths 

If you see mold on most of your shrooms, Psychedelic Passage recommends tossing the whole thing. However, if there is just a bit, you can remove and dispose of the section that has mold. 

Risks of Bad Shrooms

Using old mushrooms could make you sick.

If your magic mushrooms have signs of bacteria or fungus then you risk infections or toxin exposure according to Psychedelic Passage. 

If your shrooms are infused with another product such as chocolate, following the best-by date would be a good idea. 

People may be tempted to mix their old mushrooms with weed instead of wasting them, but we recommend tossing them, especially if they have signs of spoilage. 

However, if your mushrooms are just old, they may not pose any serious risk to your health. At the same time, you might not get a potent trip since potency decreases over time. 

How to Store Shrooms to Last Longer

The amount of time that shrooms last can depend on how well you store them as well as the harvesting method.

Mushrooms can last anywhere between a few days to a year depending on storage.

Of course, no matter how well you store them, they will eventually go bad whether by losing potency or contamination by other microbes.

Fresh mushrooms have the shortest shelf life. 

Psychedelic Passage says, “Fresh mushrooms are best consumed within a week after harvest and should be stored in a paper bag in the refrigerator. If not refrigerated, they last a few days at best.”

To make your shrooms last longer, dry them. 

Zamnesia recommends pre-drying your mushrooms first by putting them on cardboard or a towel in a well-ventilated area or in front of a fan. Make sure your shrooms aren’t in direct sunlight. This should only take a couple of hours

After your shrooms are pre dried, you can air dry them, or use a dehydrator or a desiccant. 

The 2020 study we mentioned before concluded that storing dried shrooms in a dark place at room temperature was ideal. The researchers said those conditions produced the lowest decay of tryptamines like psilocybin and psilocin which you can thank for your trip. 

Psychedelic Passage also said something similar.

“The longest-lasting conditions are found in drying and storing them in a dark, dry, cool, and air-tight environment.”

Interestingly, the researchers also found that fresh mushrooms stored at −80°C had the greatest degradation. However, most freezers aren’t that cold anyway. 

If you’re wondering what type of environment to avoid, Psychedelic Passage says, “The most important thing is to keep them away from warm, damp environments which will breed mold and bacteria, as well as away from prolonged UV exposure and oxygen.”


So, how long do shrooms last? There is no set answer because it depends on how you store them. Fresh mushrooms have the shortest shelf life while dried mushrooms have the longest. Fresh mushrooms, if stored properly could last a week or two. Dried mushrooms could last up to a year. It’s best to store your shrooms in a dry dark place. If you notice any signs of bacterial growth, it’s best to toss it. However, you may be able to remove small areas with fungus and still use your shrooms. Old shrooms may also not be very potent and probably not worth it. 

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About Trevann

Trevann is Stoner Rotation’s Jamaica-based lead writer for the Science section of our cannabis blog. She graduated with honors receiving her Bachelor of Science degree in Molecular Biology from the University of West Indies, Mona. For the last three years, she has covered some of the biggest questions around cannabis and health underpinned with research from supporting studies, medical journals and scholarly articles. Got something on your mind? You can reach her at [email protected].

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