Myrcene is one of the most common terpenes in cannabis and is often the dominant one in many strains. Its aroma is usually described as earthy, musky and slightly fruity, with a hint of clove. Outside cannabis, it is found in hops, lemongrass, thyme, bay leaves and ripe mango.
Myrcene is often associated in cannabis culture with "couch-lock" or a heavier feel, and you will see that idea repeated on many websites. The evidence for that in people is limited, and how a product feels depends on many factors, including THC content, dose and tolerance. We describe myrcene by its smell and flavor, not as a predictor of effects.
A popular story says eating mango before using cannabis makes it stronger. There is no good evidence for that, though there is no harm in enjoying a mango.
On a lab report with a terpene panel, myrcene will be listed as a percentage. If you find you enjoy earthy, musky strains, look for products where myrcene is near the top of the list, and compare a few to see what you like.
Myrcene is volatile, so it fades with heat and age. Store your flower in a cool, dark, airtight container to keep it smelling its best.