How to label your edible marijuana
Knowing the correct potency for infused edibles is important, as the effects of cannabis can be intensified by digestion compared to inhalation. This occurs because the digestive system typically delays and prolongs the onset of the medicinal effects. Clear and accurate labeling is therefore vital and necessary.
Oregon law requires that all infused edibles have proper labeling, which includes the total usable THC and CBD in the product.
When cannabis is tested at Green Leaf Lab, we report a concentration. A concentration is essentially the ratio of the medicine to the whole product. Our concentrations are reported in terms of percentage (%) by weight and also in terms of milligrams of cannabinoid per gram of product (mg/g). These numbers can assist the maker of infused edibles in better understanding their product. However, these numbers may be difficult for a patient to interpret. The difference in density of infused edibles and the concentration can be misleading. For example, an infused edible with a lower concentration of cannabinoids but a heavier density may be stronger than an infused edible with a higher concentration of cannabinoids but a lighter density (such as a rice crispy treat compared to chocolate). Refer to the illustration below.
Even though the infused chocolate appears to have a lower potency in terms of mg/g, it can pose a greater risk for high-dosing, because the volume it takes to achieve a 30mg THC dosage is significantly less than the rice crispy treat. One bite of the chocolate versus five bites of the rice crispy treat can make a difference in the end effect for the consumer.
In order to properly educate patients, we recommend that you report the total milligram values of cannabinoids, specifically THC and CBD (or the acid values if applicable). Listing the total milligrams of THC and CBD in your product, as well as the total net weight in the package, will assist in imparting more usable information. Such labeling will equip the patient with information to aid them in determining the reasonable serving size for their health needs.
The calculation is simple: multiply the concentration, in mg/g, by the total weight of the infused edible (in grams). The most important detail is to ensure that the units are correct. A few examples of this calculation process are shown in the table to the right.
Medible THC Dosage Calculator
Product Weight grams
THC Concentration mg/g