Cannabis Science

How Long Do Shrooms Last?

man holding shrooms

Even though shrooms don’t have an expiry date imprinted on them, they don’t last forever.

Photo: Unsplash

Do Shrooms Go Bad?


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

They may go bad over time or due to bacterial and mold growth.

In terms of loss of potency, research shows that shrooms lose potency over time.

How Long Do Shrooms Last?

A 2020 study that when stored in ideal conditions, the chemicals responsible for producing a 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. 

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.

Signs of Spoilage

Unfortunately, bacteria and mold can grow on magic mushrooms and at that point, should be tossed

According to Psychedelic Passage, here are signs of spoilage:

  • 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 

Risks of Bad Shrooms

Using old mushrooms could make you sick.

If they have signs of bacteria or fungus, there is a risk of possible infection or toxin exposure, according to Psychedelic Passage. 

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

People may be tempted to mix mushrooms with weed, but we recommend tossing them 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, 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.

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

Of course, no matter how well stored, they eventually go bad through loss of 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.”

Shrooms last significantly longer when dried.

Zamnesia recommends pre-drying mushrooms by putting them on cardboard or a towel in a well-ventilated area or in front of a fan. They should not be in direct sunlight. After a few hours of pre-drying, they can be air dried or placed in a dehydrator.

The 2020 study 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 are responsible for producing a psychedelic trip.

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.”


Fresh mushrooms have the shortest shelf life of just a week or two, while dried mushrooms have the longest, lasting up to a year. It’s best to store them in a dry dark place. If there are noticeable signs of bacterial growth, they should be tossed. Old shrooms tend to be less potent anyways.


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].