It’s often presented as Cannabis 101: indica strains (from the shorter, bushy version of the plant) are sedating, while sativa (from the taller, spindlier version) are more uplifting.
It’s a claim repeated on most cannabis education sites. But is it accurate?
“In brief, I would say no, it is not,” says Jason Busse of McMaster University’s Centre for Medicinal Cannabis Research.
“I think the classical characterization of indica versus sativa is not very helpful when you’re trying to understand what the active agents in the product are going to be.”
Washington State-based cannabis scientist Ethan Russo agrees. “It’s scientifically invalid. Whether it’s actually leading anyone astray, I don’t know, but these things are so interbred to make the whole discussion ridiculous.”
Part of the problem, scientists say, is that the original subspecies of sativa and indica have been hopelessly scrambled by decades of interbreeding, done in black-market conditions. The other is that there simply isn’t research that supports predicting those effects.
“It’s hard for us to know whether this is accurate or inaccurate, because it hasn’t really been studied to the extent that people would like it to be,” says Vancouver-based cannabis writer Amanda Siebert.
A quick look at some cannabis websites show that most predict the indica is sedative/sativa is energizing effect, though always with a bit of hedging.
One site says that indica’s effects are “usually described as potentially calming, relaxing or sleep-inducing,” while sativa is “usually described as potentially energizing, uplifting or mentally stimulating.” (They add that, “There is no scientific proof of these effects, which can vary from person to person based on numerous factors.”)
Another site says, “Most consumers have used these three cannabis types (sativa, indica and hybrid) as a touchstone for predicting effects,” and that “most people find” that the two subspecies have different effects.
However, a study published in October argued that years of interbreeding have made it impossible to tell the two subspecies apart.
“Categorizing cannabis as either sativa and indica has become an exercise in futility,” wrote John McPartland, who teaches at the University of Vermont’s medical school. “Ubiquitous interbreeding and hybridization renders their distinction meaningless.”
As a result, Siebert says, simply looking at a plant doesn’t tell you much about its psychoactive effects.
“People will say that a sativa plant grows skinnier leaves, and much taller, and an indica plant will grow short and stout. Does that speak to the content of THC and CBD and the terpenes in the flowers? Not necessarily.”
Some experts say that a better guide to predicting effects are terpenes.
Terpenes are the chemical compounds that make one cannabis strain smell like lemons (‘limonene‘), or another like pine needles (‘pinene‘). Combined with THC, they may also be the key to understanding why different strains of cannabis can have different effects on the mind.
“Myrcene plus THC equals sedation. Myrcene is what I call the ‘couch lock factor’ in cannabis,” Russo says.
“Similarly, limonene will produce a mood-elevating effect, strong antidepressant effect, in combination with THC. There are many others.”
In this interpretation, a plant with more of an indica or sativa appearance might have more or less of given terpene, or not as the case may be.
To confuse things further, cannabis works on different people differently. One person having one kind of experience with a strain doesn’t necessarily mean that another person will have a similar experience.
“I like to keep track of what I’m consuming, and what terpenes are in it, and then I say, ‘Oh, this had this in it, and it made me feel this way,’” Siebert says. “[But] something that works for me, that might make me feel uplifted, might cause someone else to feel tired, or sedated.”
Research, proper breeding on an illegal plant has been challenging
“It’s been virtually impossible to do research on an illegal product,” Busse says. “It’s been very difficult. So there’s a great deal of work going on right now, but there are huge gaps in our knowledge about both the short- and long-term effects.”
Most other widely sold plants — apples, for example — have very formal breeding standards. Scientists can tell you who developed any given variety, when, from what parents, and what the DNA profile should look like.
By comparison, cannabis genetics are in a state of chaos: a 2015 genetic analysis of marijuana products labelled by variety showed that strains that were supposed to be different were nearly the same, while strains that were supposed to be the same were different.
It’s not a very surprising result of the fact that the plant breeders were operating illegally, but it does put cannabis scientists at the bottom of a very tall hill. At a point where the public is full of questions, scientists are only beginning a process that may eventually lead to answers.
The only real-life situation in which an average user might want to pay attention to the difference between the subspecies is if they were thinking of growing their own, Busse says.
“If you only had a certain amount of space to grow it, you might lean toward the shorter plant. But in terms of trying to make any kind of conclusion about the potency of different cannabinoids based on whether it’s a sativa or indica strain, that’s not particularly helpful.”