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What You Should Know About Moldy Cannabis

As many agricultural products contain some level of mold, the same goes for cannabis. In fact, the most common reason cannabis fails to pass safety and compliance testing is because of its mold levels. Cannabis with mold is a huge concern for lab testing and consumers because it spreads rapidly and can cause significant health effects in high concentration levels, especially for people with mold allergies and those who are immunocompromised (Steadfast Labs, 2022).

moldy plant and what mold may look like on cannabis
Image by Andreas from Pixabay

Mold can easily form at any step in the cultivation process, as well as once the product is in the hands of the consumer. Cannabis exposed to high levels of humidity or not dried thoroughly is more likely to experience mold growth (Makowski, 2022). Mold can also form on a healthy plant with exposure to another plant containing a high concentration of mold spores.

Is Mold in Cannabis Safe to Consume?

If all cannabis has mold spores, then you may be wondering if that makes it safe to consume anyway. Consuming cannabis with mold may not have any side effects if it's at low levels, but it's better to avoid it altogether. Moldy cannabis can cause you to become extremely sick, and may even be deadly in some cases (Makowski, 2022).

Immediate reactions to consuming cannabis with mold are allergic reactions, sinus issues, fatigue, dizziness, and headaches (Makowski, 2022). You may also experience side effects such as coughing, nausea, and vomiting. An allergic reaction to consuming cannabis with mold can cause sinus pain, congestion, drainage, and wheezing (Santos-Longhurst, 2020). In the long term, heavy exposure to moldy cannabis can cause infections and other respiratory issues (Makowski, 2022).

Consuming cannabis with certain mold species may also have more serious health consequences for people with lung conditions or a weakened immune system (Santos-Longhurst, 2020). Mold species such as Aspergillus, Cryptococcus, and Mucor can cause serious health complications with potentially deadly infections in the lungs, central nervous system, and brain (Santos-Longhurst, 2020).

Moldy cannabis can also result in the production of a known human toxin and carcinogen known as mycotoxin (Steadfast Labs, 2022). If you consume moldy cannabis and begin experiencing adverse effects, seek medical attention immediately. Adverse effects or allergic reactions to moldy cannabis should not be taken lightly and can be extremely dangerous (Makowski, 2022).

How to Identify Mold in Cannabis

Moldy cannabis may be difficult to spot if you don’t know what to look for. An unhealthy plant with mold may have mold on the leaves or stems that appear powdery or fuzzy (Makowski, 2022). The plant may also have some spots of discoloration and a grayish-white cast over the stems and leaves (Santos-Longhurst, 2020).

Although, some variations of cannabis have trichomes that may resemble mold to those who are unfamiliar with the plant. Trichomes are natural for the plant to have and are what give cannabis its signature aroma. Trichomes will appear shiny and crystal-like on the plant’s stems and leaves, whereas mold will appear gray, white, and powdery (Santos-Longhurst, 2020).

Cannabis with mold will also likely emit a different, distinct aroma, often smelling musty or mildewy and even described to smell like hay. If your eyes don’t spot mold on cannabis right away, your nose may pick up on the scent of the mold first (Santos-Longhurst, 2020).

Avoiding Cannabis with Mold

If your cannabis product shows any signs of mold or it is confirmed to have mold, it’s important to dispose of the product immediately. Since mold growth can spread quickly, the best way to dispose of the product is to toss it in a sealed container like a plastic bag before placing it in the garbage (Makowski, 2022).

When purchasing cannabis, it’s important to only buy and consume cannabis that has been lab-tested. Lab-tested cannabis will ensure the product is safe for consumption, meaning its free of mold and other contaminants, and is of the highest quality. If a dispensary allows you to inspect the product before purchasing, be on the lookout for visual indicators of mold growth and smell the product. This extra step can save you from purchasing moldy cannabis and prevent any potential for an emergency room visit (Makowski, 2022).

Once you’ve purchased a cannabis product free of mold and other contaminants, it's important to know the proper storage options for preventing mold growth. In addition to humidity and improper drying, mold can also grow on cannabis when exposed to the wrong temperature, light, and oxygen levels (Santos-Longhurst, 2020).

When storing cannabis you’ll want to avoid exposing the product to low temperatures and in areas where exposure to moisture is possible. This includes storing your cannabis product in the fridge or freezer. These storage places are typically too cold for cannabis and have too much moisture. Cannabis should be stored in a dry location with an ideal temperature just below 77°F (25°C) (Santos-Longhurst, 2020).

Storing cannabis in the right container will also keep your product fresh and free of mold. Glass containers with an airtight seal such as mason jars are best for preventing mold growth as they limit the product’s exposure to moisture and oxygen. In addition to storing the product in a cool, dry environment, you’ll also want to ensure the cannabis product is stored away from sunlight in a dark location. Moisture and sunlight can cause cannabis to quickly decline, as this can create a damp environment (Santos-Longhurst, 2020).

Controlling humidity levels and limiting your product’s exposure can be difficult in environments prone to higher levels of moisture in the air. Cannabis is best stored with humidity levels around 59 to 63 percent. Humidors and humidity packs with salt and water can help to regulate moisture levels (Santos-Longhurst, 2020).

Trust in Steep Hill Illinois

Whether you are interested in laboratory testing for mold and other contaminants, data analysis, or consulting services, you can always rely on Steep Hill Illinois to assist you with accurate, reliable results on the latest cannabis production practices. Email us today at to get started!


Makowski, A. (2022, June 2). The risks of consuming mold-infested cannabis. Medical Alternatives Clinics. Retrieved April 28, 2023, from,you%20smoke%20moldy%20weed%20regularly.

Santos-Longhurst, A. (2020, March 31). Moldy weed: What to look for and how to handle it. Healthline. Retrieved April 28, 2023, from

What consumers need to know about moldy weed testing. Steadfast Labs. (2022, September 9). Retrieved April 21, 2023, from

Image by <a href="">Andreas</a> from <a href="">Pixabay</a>

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