It's a sad moment when you misplace a bag of bud only to find it dry and brown months later. Of course, even if it's dry, you don't want it to go to waste. Luckily, smoking old weed won't hurt you. However, as cannabis dries, it's chemical structure changes so that it won't have the same effect. It's important to know what kind of experience smoking old weed will produce so that you can be prepared for it and make informed decisions while you are feeling the effects.
Smoking old weed won't make you sick unless it has been stored somewhere with lots of exposure to air, heat, and moisture. In this case, the weed may have grown mold. There have even been cases of dispensaries inadvertently selling moldy marijuana. Smoking marijuana with mold on it can lead to a serious lung infection if you smoke more than a couple of puffs.
To inspect your weed for mold, look for cobweb-like filaments, sawdust-like particles, yellow or gray fuzz, a residue that looks like powdered sugar, dark spots on green buds, or slime. Also, while this may seem like a given, do not smoke weed that smells like sweat or urine – these unpleasant smells could be another sign of cannabis mold.
If you would like pictures of moldy cannabis to compare to your own stash, you can check the photos in this article. To prevent cannabis from getting moldy, either store the weed in an airtight glass jar at least three-quarters of the way full or dry and store the cannabis somewhere dry and cool for at least four weeks and then freeze it in a couple of Ziplock bags wrapped in aluminum foil. If done properly, you can potentially preserve the weed and its psychoactive effects for years.
If your weed is dry and brown, but not moldy, it's still totally safe to smoke. You just won't be smoking the same chemical compounds. A changing chemical structure is essential to marijuana's function. For example, THC, which is the psychoactive component of cannabis, starts as THCA, which is not psychoactive until you heat it with your lighter and burn off the carboxyl acid. If you leave the weed out and expose it to UV rays, the chemical reactions continue. THC turns into CBN. The longer the weed is in an environment with lots of exposure to UV, the more CBN and the less THC it will include.
CBN has none of the psychoactive effects of THC. CBN is a sedative and muscle relaxant. If you struggle with insomnia or have trouble sleeping, old marijuana might be a huge help to you. If you are looking for a trippy high, old weed probably won't provide it. The effects of CBN are important to keep in mind before you plan on engaging in any activities, since dried up weed might make you too sleepy to do much of anything.
Also, bear in mind that dried up, powdery weed is harsher to smoke, and could seriously irritate your throat if you are not careful. You could vape the weed, but since it is dried up, it will combust more quickly and produce less vapor. Keep in mind that terpenes undergo a similar transformation when exposed to UV. Any cannabis concentrate will develop more CBN, less THC, and less flavor, given enough UV exposure.
Dried up weed is chemically different from fresh green weed, but it isn't harmful. However, if you limit the weed's exposure to air, moisture, light, and UV rays, you can maintain your weeds' usability for weeks, months, or even years.