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What makes cannabis effective?

The cannabis plant contains dozens of active compounds called cannabinoids, found in various concentrations within a cannabis plant’s flowers, leaves, and stem. The majority of cannabinoids are located in the flowers of the female plant and are concentrated in a viscous resin, which is produced in glandular structures called ‘trichomes’. In addition to its wealth of cannabinoids, the resin is also rich in terpenes. Terpenes are largely responsible for cannabis’ distinct odor, as well as much of the variations in physiological effects across strains.

Cannabinoids are delivered to the body via several routes, including through smoking plant material, vaporizing concentrates, ingesting plant material, and topical application.

Researchers have identified over 70 unique cannabinoids within the cannabis plant. Many of these cannabinoids interact with the human endocannabinoid system via cannabinoid receptors found throughout our bodies.

Although scientists are still identifying new cannabinoid receptors, research has advanced at a rapid pace.

The two main types of cannabinoid receptors in the human body are called CB1 and CB2. The CB1 receptor is expressed mainly in the brain and central nervous system, as well as the lungs, liver and kidneys. The CB2 receptor is primarily expressed in the immune system, hematopoietic cells, and throughout the gut. The affinity of an individual cannabinoid to each receptor, as well as the cannabinoid’s own pharmacology, combine to determine how it will affect the human body.

Indica vs. Sativa Classification

Indicas and Sativas are two of the three recognized subspecies of cannabis (Ruderalis is the third). The geographical origins of the different varieties vary, with Sativas hailing from warm Southern Asia and Indicas from the colder Himalayan foothills of Central Asia. The differences in their respective environments led to different growth patterns and chemical compositions. It should be noted that landrace varieties are exceedingly rare and that most cannabis strains are hybridized.

In terms of effect, indicas are generally going to be more sedative and body-centric, whereas sativas are generally going to be more cerebral and energetic.  This doesn't hold true in all cases, and depends heavily on the specific amounts of cannabinoids and terpenes present in the plant.

What are cannabinoids, terpenes and flavonoids?

There are 200 or more bioactive compounds that have been discovered in the cannabis plant. Each strain has a varied profile of said compounds, which in include cannabinoids, terpenes and flavonoids.

Cannabinoids are chemical compounds which activate the cannabinoid receptors found throughout our bodies. Phytocannabinoids are the natural forms of these chemicals found in highest concentrations within female cannabis flowers - more specifically, within the resin glands on the surface of the flower. There are at least 85 different cannabinoids identified and isolated from various cannabis strains. Each has a unique influence on the body's endocannabinoid system. Some of the more common cannabinoids include ∆-9-THC, CBD and CBN. Check out our cannabinoids page for a break down of the most commonly found cannabinoids in the cannabis plant.

Secreted in the same glands that produce cannabinoids like THC and CBD, terpenes are aromatic oils that color cannabis varieties with distinctive flavors like citrus, berry, mint, and pine. Terpenes are the fragrance molecules which emanate from all plants. For cannabis, each strain has a terpene profile that contributes to each strain’s unique bouquet. Terpenes are believed to exhibit medicinal properties independent from the cannabinoids and contribute to the ‘entourage effect’ when smoking or vaporizing cannabis. Learn more about specific terpenes here.

Flavonoids have been known for some time (as they are not exclusive to cannabis, like terpenes). However, there are some that are known to be found only within cannabis. These are known as cannaflavins. Similar to terpenes, flavonoids share a role in how we perceive cannabis through our senses. Cannaflavins affect the pigmentation of cannabis. Those beautiful, deep purple cannabis strains owe their coloration to the flavonoids known as anthoxanthins or anthocyanins. In other plants such as berries, anthocyanin may cause red, purple, or even blue coloration depending on pH levels. Check out this HERB blog post about cannabis flavonoids.

​What is the ‘entourage effect?’

The interactive synergy between cannabis compounds (cannabinoids, terpenes and flavonoids) has been coined the ‘entourage effect.’ The entourage effect isn’t one primary formula. Many combinations of terpenes and cannabinoids in different amounts can be found in different cannabis strains.

It could come from a strain of cannabis containing high levels of THC, as well as limonene, a citrus scented terpene. Together, with other bioactive compounds in the cannabis strain, THC and limonene provide a very motivating and uplifting high. One thinks of the sativa dominant strain: Tangie! It could also be a difference of cannabinoid ratios for an end product. For example, you’ll find ratios of CBD to THC in certain products like vape cartridges and tinctures. See the HERB blog for more information on the 'entourage effect.’

​Where can I find more information?

Check out these HERB Educational pages to learn more about cannabis:

History of Cannabis

Methods of Consumption

Ailment Guide

Lab Testing



Vaporizer 101

The HERB Blog

Check out some of our favorite websites for general cannabis information:

Weed Maps



Merry Jane


420 Science

The Cannabist

Steep Hill Laboratories

SC Laboratories

Information courtesy of SC Laboratories, Steep Hill Laboratories and Leafly.