Tetrahydrocannabinol (THC) is the primary compound in cannabis responsible for its psychoactive effects. THC does degrade over time, leading to a reduction in its psychoactive strength. Understanding the underlying chemical changes and environmental influences can help preserve its quality.
The Chemical Journey of THC Degradation
THC undergoes a chemical transformation into Cannabinol (CBN) as cannabis ages, primarily through oxidation where THC molecules react with oxygen. The non-intoxicating precursor, tetrahydrocannabinolic acid (THCA), converts into THC through decarboxylation, a process accelerated by heat. As THC degrades into CBN, its psychoactive potency significantly reduces, as CBN is considerably less intoxicating.
Environmental Factors Influencing Potency
Several external elements accelerate the degradation of THC, impacting its potency. Exposure to light, particularly ultraviolet (UV) rays, is a significant factor, as UV radiation breaks down organic matter, including the delicate trichomes where cannabinoids reside. Heat also plays a substantial role, speeding up the decarboxylation process and further degrading THC. Temperatures above 70°F (21°C) promote this breakdown, with more rapid degradation occurring above 100°F (38°C).
Oxygen exposure is another major contributor to THC degradation through oxidation. Cannabis that is frequently exposed to air will degrade faster than that stored in a more controlled environment. The passage of time itself, even under optimal conditions, gradually diminishes THC levels. Studies indicate that THC can degrade by approximately 16% after just one year of storage, even if kept in ideal conditions. Furthermore, improper humidity levels, either too high or too low, can also contribute to degradation by promoting mold growth or causing the material to become brittle and lose its active compounds.
Practical Storage Strategies
To minimize THC degradation and preserve potency, specific storage practices are beneficial. Storing cannabis in airtight containers is crucial, as this limits oxygen exposure, a primary driver of chemical breakdown. Glass jars with tight-sealing lids are recommended because they do not carry a static charge that can damage trichomes, unlike plastic alternatives. These containers should then be kept in a cool, dark place, away from direct sunlight or heat sources. An ideal temperature range for storage is generally between 60-70°F (15-21°C), as temperatures outside this range can accelerate degradation or promote mold.
Controlling humidity is another important aspect of proper storage. Maintaining a relative humidity level between 59% and 63% helps prevent both excessive moisture, which can lead to mold, and overly dry conditions, which can make the cannabis brittle and compromise terpenes. Humidity control packs, readily available, can be placed inside storage containers to maintain these optimal levels. Avoiding refrigerators or freezers for cannabis flower is advised, as extreme cold can make delicate trichomes brittle and prone to breaking off.
The Effects of Degraded THC
When THC degrades, the user experience can change noticeably. The most prominent effect is a reduction in psychoactive intensity, as the primary intoxicating compound converts into CBN, which possesses significantly milder psychoactive properties, estimated to be about 25% as potent as THC. Consequently, instead of the euphoric and stimulating effects, consumers may find that degraded cannabis produces more sedative or drowsy sensations. Degraded cannabis may also exhibit changes in its sensory characteristics, such as a shifted aroma or a darker, more brittle appearance. While not unsafe to consume, its intended effects will differ, with CBN offering potential benefits like aiding sleep and potentially offering relief from pain or anxiety.