Myrcene

Myrcene (β-myrcene) is the terpene Leafly describes as the most common in cannabis, and its lab data bears that out for this guide: it leads the profile of Northern Lights, Blue Dream, Granddaddy Purple, Maui Wowie, Strawberry Cough and many others. Its scent is earthy and musky rather than bright, and myrcene-led strains in Leafly's data are often described as fruity or earthy. Outside cannabis, a 2021 review in Frontiers in Nutrition lists hops as its richest known source, along with lemongrass, verbena, bay and citrus, and Wikipedia adds mango, wild thyme and cardamom.

Myrcene is often credited with the "couch-lock" associated with indica-type strains. The same review repeats the claim that cultivars with more than 0.5% myrcene tend to be sedating, but it also stresses that the evidence comes from animal studies — sedative, anxiety-reducing, anti-inflammatory and analgesic effects in rodents — and that human studies are lacking. A 2024 mouse study identified it as a sleep-promoting component of lavender oil. Leafly's user data complicates the story: myrcene also leads energetic strains such as Maui Wowie and Green Crack, so it does not predict effects on its own.

One regulatory footnote: according to the review, the US FDA in 2018 stopped permitting synthetic myrcene as a food additive under the Delaney Clause after rodent cancer findings. PubChem lists its boiling point at about 166–167 °C, one of the lowest among cannabis terpenes.