Adults only (18+)

Does Weed Go Off?

If you have ever come across an old stash tucked away in a drawer or hidden at the back of a cupboard, you might wonder whether cannabis can expire or lose its effectiveness over time. Like many organic substances, cannabis is not immune to the effects of age, air and light. While it might not spoil in the same way as perishable foods, weed does degrade. The way it is stored, how long it has been kept and the conditions it has been exposed to all influence its freshness, potency and safety. Understanding how cannabis changes over time is essential for both recreational and medicinal users who want a reliable and pleasant experience.

What Happens to Cannabis Over Time?

Cannabis contains active compounds known as cannabinoids, the most notable of which is THC. Over time, THC gradually breaks down into another compound called CBN, which has a milder and more sedative effect. As this process unfolds, the overall potency of the cannabis decreases. In other words, old weed might not get you as high as it did when it was fresh. The aromatic compounds known as terpenes also degrade with age, meaning that older cannabis may lose its distinctive smell and taste. These changes do not necessarily make the cannabis dangerous to consume, but they can affect its quality and effectiveness.

Can Weed Become Mouldy or Unsafe?

Although cannabis does not have an official expiration date, it can become unsafe if it is not stored properly. Exposure to moisture can cause mould or mildew to grow on the plant material. Mouldy weed may appear fuzzy or discoloured and often has a musty smell. Consuming mouldy cannabis can irritate the lungs and may be harmful, particularly for people with asthma or weakened immune systems. If you notice visible mould or a strong, unpleasant odour, it is best to discard the product. Smoking or vaping contaminated cannabis should always be avoided.

How to Tell If Weed Has Gone Off

There are a few signs that cannabis has passed its prime. A noticeable loss of smell or a hay-like aroma can indicate that the terpenes have broken down. The texture may become overly dry and crumbly or, in damp conditions, sticky and clumped. Visually, the colour may fade from vibrant green to a dull brown. While these changes do not automatically mean the cannabis is harmful, they suggest it may no longer deliver the same effects or enjoyment. Trusting your senses of sight, smell and touch can help you decide whether to keep or discard older weed.

How to Store Cannabis for Freshness

Proper storage can significantly extend the life of cannabis. The ideal conditions are cool, dark and dry. Glass jars with airtight seals are often preferred, as they help protect against air and humidity while avoiding plastic, which can attract static and degrade trichomes. Cannabis should be kept away from direct sunlight, which can speed up the breakdown of THC and terpenes. A consistent temperature also helps preserve the integrity of the flower. Avoid storing cannabis in the fridge or freezer, as fluctuating temperatures and condensation can encourage mould growth.

Does Cannabis Oil or Edibles Expire?

Cannabis-infused products such as oils, tinctures or edibles do have expiry dates and can go off like other food or supplement products. These items are more prone to spoilage due to the presence of perishable ingredients like oils, sugars or dairy. Always check the packaging for expiration information and look for signs of discolouration, separation or foul odours. Using expired cannabis products may not only result in reduced potency but could also pose a health risk, especially if mould or bacteria have developed.

Medicinal Cannabis and Shelf Life

For those using cannabis for medical purposes, potency and consistency are especially important. Degraded cannabis may not provide the expected relief or effects, which could affect symptom management. Medical cannabis products from licensed producers often include information on storage and best-before dates. Patients should follow these guidelines carefully and contact their healthcare provider if they are unsure about a product’s safety or effectiveness after long storage.

Conclusion

Yes, weed can go off. While it may not rot in the traditional sense, cannabis loses potency and flavour over time and can become mouldy if stored in poor conditions. Proper storage helps preserve the quality and safety of cannabis for months, and sometimes even up to a year or more. If your cannabis looks or smells off, or if it no longer delivers the expected effects, it is best to replace it with a fresh supply. Being mindful about how you store your cannabis ensures that each experience remains enjoyable and effective.