Full spectrum, broad spectrum, and isolate refer to types of cannabis extracts, also called concentrates. The terms are intended to indicate the amount of plant-produced therapeutic chemicals present in addition to the primary cannabinoids (THC and/or CBD); they are a shorthand way of conveying the diversity of bioactives in a given extract. However, there is not consensus on, let alone regulatory enforcement of, definitions for these terms. In an industry with so much energy and so little alignment, it’s not surprising that there are widely differing interpretations flying around, yet the choice of extract is a foundational decision for producers.
To understand the relevance of phytochemical diversity to product development, why these terms were coined, and how they may be interpreted today, we must first discuss the Entourage Effect – and to discuss that, we must first explain the Endocannabinoid System (ECS).
The Endocannabinoid System
The ECS is an ancient network of neurotransmitters, their receptors and enzymes. It is present in all extant vertebrate species and some insects. It evolved a whopping 543 million years ago, right before the Permian Extinction, the event that nearly ended life on Earth. (Interestingly, the cannabis plant didn’t show up until 63 million years ago, in the late Cretaceous.) Humankind’s discovery of the ECS has happened gradually over the latter part of the last century, beginning in 1964 with the identification and synthesis of THC by Mechoulam and Gaoni, pioneering Israeli scientists. It was named by Italian biochemist Vincenzo Di Marzo (much of the most compelling and interesting research about cannabis comes from overseas, where research isn’t hobbled by federal scheduling), who initially outlined its influence in “eating, sleeping, relaxing, forgetting and protecting” in the early 90s. This system plays a critical role in almost every regulatory function of our bodies, that has been with us since before there were mammals, that survived a die-off of 90 percent of the planet’s species – and yet, due to persistent stigma around cannabis, we know relatively little about it.
Now that the curtain around cannabis is starting to lift, consumers are becoming more curious about which cannabis options work best for them and why. There is a lot of information out there, easily accessible through a Google search, but it is conflicting and muddled with anecdata. Most consumers do not have the time or inclination to deep-dive into cannabis science; they just want to know what they can expect. The problem is, the ECS is as unique as a fingerprint; everyone is different, and trial and error is inherent in the journey toward optimization. However, the chemicals produced in the plant alongside cannabinoids have more predictable and well-studied effects than the cannabinoids themselves. Knowing the phytochemical profile of a cannabis extract can help developers define and standardize their products at scale.
The Entourage Effect
The definition of the Entourage Effect is relatively simple: it is the theory that cannabinoids have more favorable action when delivered with a higher proportion of native phytochemicals such as terpenes, flavonoids, and other cannabinoids. This manifests as both amplification of positive effects (efficacy) and modulation of undesirable ones (tolerability). The term was coined in 1988 by Raphael Mechoulam (the same Israeli scientist who discovered THC) and its potential mechanisms were first illuminated by Dr. Ethan Russo in his landmark 2011 paper, “Taming THC.” Put even more simply, the Entourage Effect is a way of saying that, when it comes to cannabis, the whole is greater than the sum of the parts.
The interactions between various cannabinoids, terpenes, and flavonoids are staggeringly complex; it will take decades of research to parse them. Fortunately, terpenes and flavonoids have at least as much scientific research behind them as ahead of them. They are already common additives in many commercial processed goods, especially cosmetics, and of course, food – plants make tens of thousands of different terpenes alone. They can also be synthesized.
The Entourage Effect is the reasoning behind extractions that seek to retain as much of the native phytochemical context as possible. However, this comes at the expense of standardization and palatability, so each use case will necessitate its own balance of values.
Creating Cannabis Extracts
Cannabinoids are produced most abundantly in the resin glands of the cannabis plant, called trichomes. To be used in processed beverages or topicals, these glands must first be concentrated, then their oils separated from plant waxes and other non-useful vegetative matter. There are two main categories of processes to do this: solvent and non-solvent. Various levels of technological sophistication exist within each category, and most finished extracts employ elements of both.
Solvent: In this method, a solvent is added to dissolve the cannabinoids, then evaporated, leaving a concentrated oil. Solvents can be further divided by polarity. Non-polar solvents, such as butane, dissolve only non-polar compounds from the plant, in this case the oils and other lipids making up the trichome heads. Polar solvents, such as ethanol, will extract both non-polar and polar compounds, including water-soluble compounds such as chlorophyll. These bring with them with strong herbaceous flavors, however many polar compounds are desirable from a therapeutic standpoint.
Non-solvent (Mechanical): Mechanical extraction processes vary from ancient hand-pressed hash to modern distillates. Using temperature or pressure changes, cannabinoid oils can be separated without the use of a solvent. Distillation uses the variability in boiling points of a plant’s constituent chemicals to yield very pure extracts. Solvent-extracted concentrates are evaporated and then condensed at precise temperatures. The resulting product typically tests at 85-97% purity.
Full Spectrum, Broad Spectrum, and Isolate
Now that we have covered the reasoning and methods for creating cannabis extracts, here are the terms used to categorize them.
Full Spectrum means the maximum amount of helpful native phytochemicals are retained during extraction, including THC. There are no precise regulatory definitions, but the goal is to remove extraneous lipids while retaining an identical ratio of cannabinoids, terpenes, and flavonoids from the original plant source material. (This can only be verified by testing the material before and after the extraction.) True full spectrum extracts are more rare than one might expect; most extractions lose significant terpenes and flavonoids during processing because they are much more volatile than cannabinoids. Ethanol and very low heat (the RSO method or whole plant oil), or an extremely long vacuum extraction process can yield full spectrum extracts.
Broad Spectrum applies to extractions which aim to retain a large complement of phytochemicals, but without the THC. This allows for some Entourage Effect action without the stigma and intoxication that accompanies cannabis’ most notorious component. Hemp, defined as cannabis plants containing <.3% THC, forms the basis for most broad spec extracts. Broad spectrum can also be created by either adding terpenes, flavonoids, and minor cannabinoids to CBD isolate or by removing THC from full spectrum extract via distillation.
Distillate takes quite the opposite approach of full spectrum, seeking to remove everything but the cannabinoid(s) of interest. After undergoing solvent extraction, the concentrated oil is run through the short-path distillation process described above, often multiple times, to purify it. Some suppliers will advertise “full-spectrum distillate” but this is contradictory. If terpenes or other bioactives are reintroduced after distillation, the product is sometimes also called broad spectrum.
Isolate is the purest form of extracted cannabinoids, a crystalline powder with a purity of 99.9%. It is created through additional solvent processes after distillation. The additional processing steps are expensive, but due to the extreme purity of the final product, cheaper crude extracts can be used as starting material without concern for residues.
Choosing the Right Spectrum
Both full and broad spectrum concentrates offer the benefits of the Entourage Effect. At first glance, it may seem that using the most phytochemically diverse extract is a no-brainer: CBD is a weak actor on its own, but its action can be amplified with other cannabinoids, terpenes, flavonoids and sterols. If your CBD product is relatively low-dose, having a diversity of phytochemicals is even more important. Beyond their potential therapeutic effects, all these minor players also give cannabis its depth, creating a symphony of flavor and smell, and ultimately making the bitterness of cannabinoid extracts more palatable.
However, even a pleasant symphony of flavors can have a strong personality; it will never be a neutral canvas onto which flavor scientists can project their artistry. Rather, it is a dominating flavor of its own – and one that changes with every batch of extract. In emulsions, the diversity of chemicals, each with slightly different weights, is also a challenge. Full and broad spectrum extracts are wild cards, and in large-scale commercial applications, the variability that makes them beautiful also make them unpredictable in terms of flavor.
By contrast, distillates and isolates offer consistency and standardization; they are a known quantity. Without much personality of their own, one can use a wider variety of flavorings to make the formulation really shine, and they are far more consistent in emulsions (as long as the supplier is reliable). The consumer can also expect the same effects and sensory experience every time.
Choosing the correct starting material for product development is a careful balance of values. For most commercial purposes, purer extracts are desirable because they allow producers to standardize and iterate based on known, reliable effects. However, for the more wellness-focused, the benefits of a fuller complement of phytochemicals are worth the variability.
At SōRSE, we have often sought to strike a balance between standardization and efficacy. Many of our products are what I like to call “Designer Spectrum” – they reconstruct the phytochemical profile block by block to yield a consistent but fully articulated product – similar to molecular gastronomy, but for cannabis.