Article by The Leaf News
Dear Herb: I bought some legal weed the other day, and on the bottle it says, “THC 0.27 per cent.” Next to that, it says, “Total THC 16.9 per cent.” What does this mean? — Multiple Choice
Dear Multiple Choice: Excellent question. I suspect this is confusing to lots of cannabis consumers in Canada these days.
If you’re at all familiar with cannabis, you know that THC — tetrahydrocannabinol — is a cannabinoid, one of the key chemical compounds produced by cannabis that causes a psychoactive effect when ingested. The proportion of THC in cannabis is generally considered a rough measurement of the potency of the cannabis. (In reality, other factors such as terpenes also play important roles in how cannabis affects human physiology, but let’s leave that aside for now).
However, cannabis plants don’t actually produce THC; instead, fresh cannabis buds contain THCA (tetrahydrocannabinolic acid), which is a non-psychoactive substance — it won’t get you high. When that cannabis is heated sufficiently, the THCA is converted to THC by way of a chemical process called decarboxylation.