The labels "Indica" and "Sativa" are commonly used to describe cannabis strains, but what is the actual difference between these two labels? Despite some people claiming that Indica strains are sedative with earthy aromas, and Sativa strains are energizing with sweet aromas, it remains unclear if these labels actually capture any meaningful information.

A team of researchers at Dalhousie University worked with Bedrocan International, a Dutch medical cannabis company, to study hundreds of cannabis strains with Indica and Sativa labels. They measured the chemical compounds produced by each strain, including major psychoactive cannabinoids like THC and CBD, as well as terpenes that give cannabis its distinctive aromas. The researchers also measured the genetic profiles and examined the chemical and genetic differences between strains.

The study, published in Nature Plants, found that Indica and Sativa labels are largely meaningless. The strains labeled Indica were often just as closely related to strains labeled Sativa as they were to other strains labeled Indica. The names given to strains were also found to be unreliable indicators of a plant's genetic identity and chemical profile.

The history of Indica and Sativa is similar to a long game of broken telephone, where words can easily get twisted. At one point, Indica and Sativa may have been used to describe two distinct species of cannabis, but over time, the two species likely hybridized, resulting in most cannabis being a mix of the two ancestral lineages. Despite this, the use of Indica and Sativa persists as vernacular labels and has taken on new meanings to describe psychoactive effects, aromas, and morphologies.

The researchers found weak correlations between Indica and Sativa labels and a small number of aromatic terpenes. Strains labeled Indica tended to have higher amounts of the terpene myrcene, which is thought to contribute to sedation and the more intense "couch-lock" effect. On the other hand, strains labeled Sativa had higher amounts of sweet and herbal terpenes, like farnesene and bergamotene.

There is a need to revamp how cannabis is labeled and clearly communicate its effects. The current way of labeling and naming cannabis strains appears to fall short of the labeling standards applied to other agricultural crops. Cannabis is an incredibly diverse crop that produces over one hundred aromatic and psychoactive compounds with distinct aromas and effects. The researchers suggest abandoning the use of the terms Sativa and Indica altogether and instead labeling cannabis with the quantities of key compounds that have medicinal effects or are known to affect consumer preferences.