Everyone Says Pot Is More Potent Now Than 30 Years Ago…But Is It?

Mar 23, 2015 at 10:59 AM ET

Conventional wisdom among the media and potheads would have it that weed is way stronger than it was a generation ago. Even researchers have boasted that with THC levels as high as 30 percent, marijuana strains available today dwarf the potency levels of three decades ago. Others in the field, however, are skeptical of these claims.

“We’ve seen a big increase in marijuana potency compared to where it was 20 or 30 years ago,” President and Director of marijuana testing facility Charas Scientific Andy LaFrate, said in a video released by the American Chemical Society. “I would say the average potency of marijuana has probably increased by a factor of at least three. We’re looking at average potencies right now of around 20 percent THC.”

He added that three decades ago THC levels typically fell below ten percent. The higher potency today is the result of crossbreeding strains to meet consumer demand for stronger, longer highs.

However, some doubt the figures above, noting that the scientific method behind them just doesn’t pan out. “It’s fair to be skeptical.” Michael Kahn, the president of Massachusetts Cannabis Research told The Atlantic. “Back then the predominant method of quantitation was gas chromatography, which is not quite appropriate for cannabinoid quantitation. This is because [it] heats up the test material before analysis, which also alters the chemical profile—including breaking down the THC molecule,”

This lack of consistency in testing methods over the years has made it very hard—perhaps impossible—to compare strains across decades. For a true answer about the relevant potency of today’s marijuana, one would have to run a perfectly preserved sample of older marijuana against today’s strains—something very, very unlikely given the highly perishable nature of the plant and the relevant chemicals as well as its restricted status.

None of this is to say that today’s weed isn’t more potent than that which was available a generation or more ago. Given the intense horticultural efforts that have been expended on the plant over the last decades, it’s likely that it is. Making clinical claims and floating numbers to argue for the relative potency of Bubba Kush or Sour Diesel over the weed your parents smoked might be harder than previously thought.