When discussing the safe use of medical cannabis, most attention turns to the kind of cannabinoids, their effects, and the proper dosage, schedule, and journaling of effects. However, another important consideration is whether medical cannabis expires and what the warning signs are.

First of all, in its dried form, cannabis is like any other dried herb, and will lose its essential oil content and degrade over time. However, dried medical cannabis does not really expire so much as it loses its freshness and transforms over time, under certain conditions. We’ll talk about the warning signs of cannabis that is unsafe or not fresh, and then discuss how the cannabinoid profile may transform under certain storage conditions.

The only way in which cannabis can become unsafe over time is if it become mouldy as a result of exposure to significant humidity. However, dried cannabis purchased from a Licensed Producer should be dry enough to avoid this problem. On the other hand, excessive air and direct sunlight can make cannabis drier and stale, which is not as dangerous but does reduce its effectiveness and usability.

Cannabis naturally produces a substance called cannabigerolid acid (CBGA) over time, which is then synthesized into CBDA, CBCA, or THCA. Through heating the herb (‘decarboxylation’), these acids are transformed into the CBD, CBC, and THC – the cannabinoids we are familiar with. However, if cannabis is exposed to too much heat or sunlight over a period of time, the THCA may instead be converted into CBNA, which then becomes CBN. This cannabinoid is less psychoactive than THC, produces a shorter euphoria, and induces quite significant drowsiness. In fact, 5mg of CBN is as effective as 10mg of diazepam, a mild sedative!

There are several ways to check your dried cannabis for freshness and safety:

  1.  Smell: cannabinoids hold up better than terpenes, which will break down more quickly. If you find that your stored cannabis does not have the strong smell it should have (i.e. for a dry CBD or THC), than it is an early sign that it is less fresh. If, however, you detect musty or mildew like smells, than it is likely mould and should not be consumed.
  2.  Appearance and touch: if the cannabis is too dry, it will break apart very easily into a fine powder. Mould will produce a fine white powder and make the cannabis feel moist. Healthy cannabis will collect resin outside of the flowers, so it may be a bit sticky! Finally, if the colour is off (i.e. browning), it is also a sign that it is not fresh.

If it is cured and stored properly, dried medical cannabis can last from 12 to 18 months without losing potency. Health Canada recommends that dried cannabis should be kept in a cool, dark place, out of the reach of children. Ideally, it would be kept in an airtight container, and should be vacuum sealed if anyone plans to store it beyond 6 months. Oils, on the other hand, are food products and can actually expire.

Although all of the above is important to keep in mind, medical users should rarely encounter issues with freshness when purchasing controlled amounts from Licensed Producers. As always, if you have any questions or concerns about your medical cannabis, a Patient Coordinator at Hello Cannabis is ready to assist you!