Unless something drastic occurs, it seems likely that the U.S. is on the road to eventual cannabis legalization. It is only a matter of time. Between now and then, we need to have serious discussions about cannabis potency. It matters. It matters a lot.
Potency refers to the concentration of delta-9 THC in a cannabis plant or cannabis-derived product. It applies to both medical and recreational cannabis. It’s important because potency has an impact on how the body responds to the THC.
The big concern right now is high-potency cannabis. We do not know enough about it to unequivocally say that it’s safe. And in fact, a growing body of evidence is pointing in the other direction. It would appear as though long-term use of high-potency cannabis could result in serious adverse effects.
Not Your Grandfather’s Cannabis
Modern cannabis plants are nothing like the plants that were being grown some 50 years ago. For starters, most commercial plants are not grown from wild seeds. They are cultivated from existing plant seeds. Different plants are crossbred for the purposes of manipulating cannabinoid and terpene profiles. In particular, growers are actively seeking to increase THC levels.
They are succeeding. A 2024 article published by Psychology Today suggests that the marijuana found at Woodstock in the late 1960s had a THC volume of about 1%. Modern plants can have concentrations of 15% or more.
While the Woodstock claim has never been proven, the University of Mississippi’s Potency Monitoring Program has been monitoring cannabis potency since the early 1970s. When they first started, THC concentrations were around 1.5%. Today they are in excess of 16% – marking a tenfold increase.
The Potential Impacts
This matters because of the potential impacts of long-term exposure to high levels of THC. According to the same Psychology Today article, high-potency cannabis consumption is linked to higher risks of cardiovascular problems, psychosis, depression, suicide, and dependence.
The best way to understand potential risks is to think of it in terms of alcohol. Drinking a single glass of wine per day is not likely to lead to long-term health conditions. But drinking two glasses of whiskey is another matter. Whiskey has a higher alcohol concentration than wine.
We know that long-term consumption of high amounts of alcohol has negative impacts on human health. Excessive drinking is linked to all sorts of conditions, including liver and heart disease. It would appear that THC is no different.
THC and Medical Cannabis
In theory, potency should be less of an issue among medical cannabis patients. This is primarily due to what is known as the ‘low and slow’ approach.
Brigham City, Utah’s Beehive Farmacy explains the ‘low and slow’ approach as starting with the lowest dose of THC and the least frequent consumption is possible. It is what Utah pharmacists recommend to patients. You start low and slow, gradually increasing dose and frequency until you reach a level that relieves your symptoms. Then you go no higher.
Because medical dosages are tightly controlled under proper supervision, patients are not expected to be exposed to high-potency products over long periods of time. So the real risk with high-potency cannabis is on the recreational side of things.
Too Much of a Good Thing
While one could make the case that low-potency marijuana plants posed very little risk 50 years ago, today’s cannabis is a whole new world dominated by high-potency plants. It would appear as though cannabis users can get too much of a good thing. So we need to have this discussion before full federal legalization.
