How to Tell If Weed Is Moldy (And Whether You Should Smoke It)

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Plus, storage tips to prevent mold on weed and keep it fresh

Co-authored by Riley Kirk, PhD and Marcus Pruitt, BS

Last Updated: June 18, 2025 Fact Checked

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Signs of Moldy Weed

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Can you smoke moldy weed?

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Can you get rid of mold in weed?

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Health Risks

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Preventing Moldy Weed

If your weed has been sitting in a container for a long time, it's possible that it's grown some mold. A musty smell and fuzzy white and green spots are a dead giveaway that your bud may be past its prime. In this article, we’ll tell you everything you need to know about moldy weed, including what it looks and smells like, what happens if you smoke it, and how to prevent your weed from molding in the first place. Read on to learn more and enjoy your high in peace!

What does mold look like on weed?

Moldy weed can look white and fuzzy or dark and mushy, depending on the type of mold. The weed will also have a musty smell similar to a damp basement. Smoking moldy weed isn’t life-threatening, but it is a health risk.^{[1]
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Riley Kirk, PhD
Cannabis Research Scientist and Educator

Expert Interview} If you smoke moldy weed, you may experience sinus issues, fatigue, dizziness, and headaches.

Section 1 of 5:

Signs of Moldy Weed

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A gray and/or white coating that's powdery, fuzzy, or mushy If you see a white powder, that may be a sign of powdery mildew, which is a type of mold that is dangerous to consume. You may also see dark green or brown spots, white fuzz, or yellow and brown leaves. These are all also signs of mold.^{[2]
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- Bud rot, or botrytis cinerea, contributes to a lot of the discoloration in moldy weed. It is a mold disease that’s extremely dangerous to cannabis plants. It's only noticeable after the mold has begun breaking down the plant.^{[3]
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- Gray or white mush with yellow and brown leaves indicates of bud rot.
- Don’t confuse white powder with trichomes. Trichomes are shiny, crystal structures that are spread throughout the surface of cannabis flowers. Moldy weed, on the other hand, is clustered with a dusty, fuzzy look.^{[4]
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A musty or mildew scent that smells like a damp basement If the mold is well developed, you may smell something similar to hay, pee, or sweat. The smell may seem off to your nose, especially compared to regular weed. Regular weed usually has an earthy, skunky aroma. If you open up a pack and your nose is greeted with a whiff of gym sweat, skunk, and morning mildew, it may be best to discard it.^{[5]
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- Inhaling mold can introduce harmful spores to your body, so it’s best not to take constant whiffs of moldy weed.
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Mold has an earthy flavor that is similar to wet dirt. It may also leave an off or sour taste. Mold can also leave a metallic taste in your mouth as it progresses through your body.^{[6]
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Research source} While you may not notice much of a difference if you smoke moldy weed, consuming moldy weed in the form of homemade edibles or gummies will be far more noticeable.^{[7]
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Section 2 of 5:

Can you smoke moldy weed?

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Even if you don’t notice any initial negative effects, that doesn’t mean smoking moldy weed is safe. You can’t always tell how much the mold has spread through your weed. Mold spores can be microscopic, which means they may be present in your weed even if you don’t see it. Even if you pick off the moldy chunk, you don’t know how much it has spread. So, if you notice signs of moldy weed in your stash or feel unsure about smoking it because of a weird smell or look, it’s best to get rid of it in favor of your health.^{[8]
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Riley Kirk, PhD
Cannabis Research Scientist and Educator

Expert Interview}

Section 3 of 5:

Can you get rid of mold in weed?

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Although decarboxylation (the process of heating weed to activate the THC compound) is rumored to get rid of mold in weed, there are species of mold that thrive in heat, like Aspergillus, that will still be present in your weed after the fact. Although you may be tempted to take the moldy chunk off of your weed and smoke the rest, this may not be safe, as mold spores can spread through the buds without being seen.To stay safe and healthy, it is best to not consume weed that has molded.^{[10]
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Riley Kirk, PhD
Cannabis Research Scientist and Educator

Expert Interview}

Section 4 of 5:

Health Risks of Moldy Weed

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Reactions to moldy weed range from coughing to severe infection. If you are not very sensitive to mold, a mild cough or throat irritation may be the limit to your symptoms. If you are sensitive or allergic to mold, however, you run the risk of a lung infection or a weakened immune system.^{[12]
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Research source} Other serious signs of a bad reaction to the mold include chest pains, brain fog, congestion, and mold balls.^{[13]
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- Mold balls are fibers of fungus that can get caught in your lungs. They are caused by Aspergillosis, which is a type of mold infection.^{[14]
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  Mayo Clinic
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- Smoking moldy weed can cause Aspergillosis, which is more dangerous when smoked and inhaled.^{[15]
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Section 5 of 5:

How to Prevent Moldy Weed

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To prevent moldy weed, store your stash in a cool, dry, dark area. Areas with high humidity and moisture are ideal for mold growth. To prevent your weed from being exposed to moisture-inducing conditions, keep it in an airtight container^{[16]
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Riley Kirk, PhD
Cannabis Research Scientist and Educator

Expert Interview} in a dry, dark area like a cabinet or drawer. Too much light exposure can degrade your weed or generate heat that leads to humid conditions, so don’t let it sit in the sun all day. Weed does best at 59-63% humidity around room temperature, so keep it around there to avoid mould growth.^{[17]
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- If stored in warm and moist conditions, mold can start growing on weed in as little as 24 hours.^{[18]
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  Federal Emergency Management Agency
  Federal agency responsible for coordinating responses to disasters and states of emergency
  
  Go to source} If left in warm, moist conditions, your weed may begin to grow mold.^{[19]
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- Don’t use a fridge or freezer to store your weed, as the low temperature and exposure to moisture can facilitate mold.
- Use a mason jar or a weed-specific container to store your weed, they are airtight!
- It's best to purchase weed from a licensed dispensary since their storage and handling processes are designed with optimum quality in mind.
EXPERT TIP

Jamie Corroon, ND, MPH
Medical Director of the Center for Medical Cannabis Education
Dr. Jamie Corroon, ND, MPH is the founder and Medical Director of the Center for Medical Cannabis Education. Dr. Corroon is a licensed Naturopathic Doctor and clinical researcher. In addition to clinical practice, Dr. Corroon advises dietary supplement and cannabis companies regarding science, regulation, and product development. He is well published in the peer-review literature, with recent publications that investigate the clinical and public health implications of the broadening acceptance of cannabis in society. He earned a Masters in Public Health (MPH) in Epidemiology from San Diego State University. He also earned a Doctor of Naturopathic Medicine degree from Bastyr University, subsequently completed two years of residency at the Bastyr Center for Natural Health, and is a former adjunct professor at Bastyr University California.

Jamie Corroon, ND, MPH
Medical Director of the Center for Medical Cannabis Education

It is best to buy your weed from a reputable, licensed dispensary. Licensed businesses must comply with regulations that promote safety and product quality. Dispensaries should display their license prominently in the dispensary and on their website.