Originally published November 15, 2021. Updated September 2026 with graded outcomes.
On November 15, 2021, we asked seven cannabis and hemp professionals how research on the entourage effect would change the industry. The entourage effect is the idea that the cannabinoids, terpenes, and flavonoids in cannabis work together and produce effects that differ from those of any single compound.
The term was coined in 1998, and research on how cannabis compounds interact goes back to the 1970s. Five years after our roundup, we checked each expert's answer against what happened in the market, in regulation, and in research.
The two questions we asked in 2021: how does developing scientific knowledge of the entourage effect shape:
1) the growing and extraction of hemp and cannabis?
and
2) the way in which products are marketed to consumers?
Their 2021 answers appear below as originally published, followed by a grade for each prediction. Job titles are the ones each person held in 2021.
How we graded the predictions
We pulled every prediction from the 2021 answers that could be checked against public evidence, which gave us 12. When one expert made several predictions, each one is graded separately.
Each prediction gets one of four grades:
Happened: the prediction describes the market, research, or regulation in 2026 accurately.
Partly happened: the direction was right, but the scale or timing was off, or it happened in some markets and not others.
Didn't happen: the evidence points the other way.
Too early to tell: the prediction depended on an event that has not happened yet.
True Blue sells terpene products, so we held predictions that favor terpenes to the same standard as the others. Five of the 12 did not happen.
Michael Walters: solventless products and terpene testing
Michael Walters was Director of Content & Marketing at PotGuide in 2021
In 2021, Walters said change was already under way. He saw a growing share of consumers looking past THC content for the more balanced experience he associated with full-spectrum products.
“As many people are beginning to realize, specific terpenes can influence effects much more than THC alone,” Walters said. “Additionally, having an understanding of the entourage effect and what terpenes you prefer can make it much easier to find products that work for you and offer an enjoyable experience.”
As an example, he said some people avoid sativa strains because they expect the effects to be too intense. In his view, milder sativa options exist and can be identified by high pinene or myrcene content.
Walters said that the influence of the entourage effect on production could be seen in the growing popularity of concentrates made without using solvents.
“Oftentimes lower in THC and higher in terpene content, solventless products like rosin are becoming some of the most sought after products on the market because they provide a rich experience that is full-bodied and immersive into the plant's true properties,” he said, adding:
"More and more extractors are experimenting with terpene isolation and creating some very interesting products. Similarly, we now have a good handful of growers who refer to themselves as "resin farmers" or cultivators who specifically grow plants to make into concentrates. This ideology is obviously rooted in resin production but also terpenes. Circling back to solventless, most resin farming is done for solventless operations and rosin pressing. These products are in high demand not for their THC content but for the full-spectrum experience they provide. I think this is a clear indicator that people are looking for a more refined experience and taking increased notice of the entourage effect."
On marketing, Walters expected more companies to answer customers' questions about terpenes. In 2021, many companies did not test their products for terpene content, and he predicted that would soon change.
“I think nine out of 10 consumers are very intrigued by any packaging that contains terpene testing information and the companies that invest in the time and effort to do so are seeing positive results,” Walters said. “If federal legalization occurs and brands continue to push messaging that encourages consumers to take time finding products that work for them, we will continue to see increased awareness about the benefits of terpenes.”
Five years later: what happened
Happened. Solventless concentrates such as rosin would become some of the most sought-after products.
Solventless sales grew quickly after 2021. BDSA retail data showed demand for solventless extracts up 132% from June 2021 to June 2022, and by January 2023 rosin made up 14% of all dab sales, rising above 20% in Colorado and California. Solventless is still a smaller, premium share of the total cannabis market.
Partly happened. More brands would test for terpenes and show the results on packaging.
Some regulators now require terpene data. New York requires licensed labs to report terpene levels as a percentage by weight, and during the state's 2022 rulemaking, public commenters asked for terpene information on required labels. Terpene results are still not standard on packaging across US markets, and shoppers often have to find them in the certificate of analysis (COA), the lab report for a product batch.
Too early to tell. Federal legalization would lead to wider awareness of terpenes.
Federal legalization has not happened. On April 28, 2026, the federal government moved marijuana under a state medical license, and FDA-approved marijuana drugs, from Schedule I to Schedule III. Adult-use cannabis remains in Schedule I while the DEA holds hearings on broader rescheduling.
Matan Weil: condition-specific products and effects labels
Matan Weil was Head of Content Strategy for The Cannigma in 2021
Weil approached the question from the research side. He expected a better understanding of the entourage effect to let the industry develop products aimed at specific uses.
“Once we understand how the different molecules in cannabis, particularly cannabinoids and terpenes, interact with each other, and how chemovars (aka strains) can affect us in different ways, growers will be able to cultivate specific products for specific conditions and symptoms such as pain, seizures and nausea,” Weil said. “And at the same time, consumers would be able to predict effects, such as calming and sedating vs energizing and uplifting.”
Two reviews we cited in 2021 covered this research: a 2019 review in Frontiers in Plant Science and a 2020 review in Current Neuropharmacology. Many of the terpene findings they summarized came from laboratory and animal studies rather than human trials.
The 2020 authors wrote that further research was needed on whether adding terpenes to CBD treatment has therapeutic value.
On marketing, Weil expected companies to explain what their lab results mean for the buyer instead of only printing the numbers. He believed this would give customers better information and reduce trial and error:
"As a consequence of a deeper understanding of the entourage effect, markets could promote the likely effects of specific cannabis products, rather than just listing the concentrations of cannabinoids and terpenes. This means customers would have less trial and error to go through, and instead be able to rely on the effects listed on the labels. Instead of focusing on strain names or sativa/indica origins (which mean very little), we'd see more weight going to symptoms, conditions and effects."
Five years later: what happened
Didn't happen. Growers would breed cannabis for specific conditions such as pain, seizures, and nausea.
We found no controlled human trial showing that a specific cannabis cultivar treats pain, seizures, or nausea. The one cannabis-derived medicine with FDA approval for seizures, Epidiolex, is purified CBD rather than a whole-plant product. In the US, companies cannot market cannabis or hemp products as treatments for disease without FDA drug approval.
Partly happened. Labels would describe likely effects instead of strain names or indica/sativa.
Research since 2021 supports Weil's point about labels. A 2022 study in PLOS ONE analyzed cannabinoid and terpene data from commercial cannabis in six US states and found that indica, sativa, and hybrid labels did not consistently match the products' chemistry.
Some brands now sell by intended effect, such as sleep or energy, but indica, sativa, and strain names are still widely used on shelves and menus. Effects-based marketing also drew criticism: in 2022, edible makers told Leafly that products made from distillate cannot deliver strain-specific effects.
Lana Braslavskaia: THC potency and what buyers value
Lana Braslavskaia was, in 2021, a cannabis connoisseur and public relations specialist with AskGrowers.com
In 2021, Braslavskaia said many consumers still believed that more THC meant a better product. She expected that belief to fade as people learned more about the entourage effect.
“At AskGrowers we speak with cannabis labs, brands, growers and consumers on a daily basis,” she said. “We’ve found a common misconception with consumers is that a high THC content equals a superior product. Cannabis isn’t just about the high, but like wine or craft beer, is about the flavors and taste. For people trying cannabis for the first time, products with lower doses of THC may be an easier option for them.”
Braslavskaia said the answer was education. In her view, marketing should explain what to expect from different products, and businesses that did not do this would fall behind:
"It’s important that marketing educates the public about how different compounds in cannabis products affect their experience. Products containing THC that have other components of cannabinoids and terpenes in them often have greater therapeutic benefits. Once customers are educated through more research and technology, this will directly affect growers, extraction brands and retailers. Those in the industry that don't respond will play catch-up."
Five years later: what happened
Didn't happen. Consumers would stop assuming that higher THC means a better product.
THC percentage still drives flower sales. In California, Headset data through July 2025 show that flower labeled 28% to 30% THC sold about 6% more units and brought in 12% more revenue than flower labeled 25% to 27%, even though fewer high-THC products were on shelves. A study of more than 700,000 flower products in 30 states found that a 10% increase in THC content was linked to a 1.7% higher price.
There are signs of change in other product types. Low-dose edibles and cannabis beverages are among the faster-growing categories, according to BDSA data reported by MJBizDaily.
Kirsten Thornhill: new research and entourage marketing
Kirsten Thornhill was, in 2021, a Ph.D. student at Rocky Mountain University of Health Professions specializing in human performance, vascular health, and holistic alternatives for athlete recovery
Thornhill expected a better understanding of the entourage effect to change every part of the industry. She said that “as additional research, clinical trials, systematic reviews and meta-analyses emerge, the understanding and application of the entourage effect will bring new meaning, insight, and influence to the cultivation, education, and marketing sectors of the cannabis/hemp industry.”
A 2018 review published by IntechOpen is an example of the research she described. It covered CBD and terpenes and discussed whether CBD-rich extracts act differently from purified CBD.
The review cited a laboratory study in which CBD-rich extract produced stronger responses than purified CBD in hippocampal neurons, the brain cells involved in learning and memory. This was a lab finding, not a human trial.
Thornhill expected manufacturers to use this kind of research to adjust their processes, noting that “cultivators may preserve certain parts of the whole plant in order to better elicit desired effects for consumers.”
Like Walters and Weil, she expected a shift in marketing in which “companies make claims for their products in regards to the involvement of the entourage effect and what their products may ‘elicit’ in consumers.” She said this would help businesses adapt to a new climate in which “customers better understand what the entourage effect is and what it does to their bodies.”
Five years later: what happened
Partly happened. New trials and reviews would add evidence about the entourage effect.
Research grew, but the results point in different directions. Several lab studies found that common terpenes do not act on cannabinoid receptors or change how THC acts on them, while a 2021 mouse study and a 2024 Johns Hopkins trial found interactions. The details are in the research section below.
Happened. Brands would market products using entourage-effect claims.
Entourage-effect language is now common in CBD and cannabis marketing, especially for full-spectrum products. Market research firms describe demand for full-spectrum CBD as driven by the entourage effect, even though the human evidence is still limited.
Louis O'Neill: CBD regulation and isolate products
Louis O'Neill was, in 2021, the manager of The Green Fund and host of The CannaCast podcast
Several experts expected products to be marketed by their specific effects. In 2021, regulation made that difficult: the FDA did not allow companies to market CBD products to treat diseases or for other therapeutic uses, and other Western countries had similar rules.
O'Neill said science could solve this problem. He expected regulations, which varied widely by country and by state, to become clearer and more consistent as knowledge of cannabis science grew:
"CBD and other cannabinoids have always occupied this legal gray area because they aren't quite psychoactive but they are still part of the cannabis family. A greater understanding of the plant and its components will help to clarify things from a regulatory perspective as well as a marketing perspective as we are only in the very early stages of truly understanding what cannabinoids can do."
He added that wider public understanding of the entourage effect might end demand for pure isolate products.
“If the entourage effect proves to be even stronger than we initially supposed, isolate cannabinoids will almost immediately lose their marketability,” he said. “If the sum of the cannabis plant is more beneficial than its parts, why isolate just one?”
Five years later: what happened
Didn't happen. Better science would make cannabinoid regulation clearer and more consistent.
Rules became stricter in several places, and they are not more consistent. In January 2023, the FDA concluded that its food and supplement rules are not appropriate for CBD and said Congress would need to create a new pathway. As of September 2026, Congress has not done so.
In November 2025, Congress changed the federal definition of hemp. Starting in late 2026, products with more than 0.4 mg of total THC per container no longer count as hemp, a limit that may reach some full-spectrum CBD products.
In Europe, the European Food Safety Authority (EFSA) set a provisional safe intake for CBD of about 2 mg per day for a 70 kg adult. It said safety could not be established for people under 25, pregnant or breastfeeding women, or people taking other medications.
Didn't happen. CBD isolate products would lose their market.
CBD isolate is still widely sold, and some 2025 market reports list it as the largest segment of the CBD market. Recent rules also favor isolate: EFSA's provisional safe intake applies only to CBD that is at least 98% pure, and the new US limit of 0.4 mg total THC per container is easier to meet with THC-free isolate than with full-spectrum extracts.
O'Neill's prediction depended on the entourage effect proving stronger than expected. As of 2026, that has not been shown in people.
Browse our sativa strain terpenes.
Kristen Williams: whole-plant products and extraction
Kristen Williams was the CEO and Creative Director of Hempsley in 2021
Williams expected cannabis products to become more varied as research on the entourage effect grew. Like the others, she predicted that THC would stop being the main measure of a product:
"I believe that THC has been coveted by consumers because it's the only part of the plant we've really understood until recently. With all the restrictions on research due to Schedule I status, science has been forced to focus on understanding the mechanism behind the “high” that cannabis can provide—but with expansion in research, the entourage effect is showing that cannabis has more to offer than just a “high” or THC."
A 2011 paper by Ethan Russo in the British Journal of Pharmacology, “Taming THC: potential cannabis synergy and phytocannabinoid-terpenoid entourage effects,” is the source of much of the modern discussion of the entourage effect. It reviewed whether other cannabinoids and terpenes could change or add to the effects of THC.
Russo proposed that breeding plants for specific terpene and cannabinoid combinations should be studied as a possible treatment approach for several conditions. That was a hypothesis for future research, and it has not been confirmed in human trials.
Williams said studies like this one were creating “demand for whole-plant products rich in diverse cannabinoid profiles.” She added: “This will inevitably push the market to refine extraction methods to preserve the entirety of carefully bred plant genetics which were grown to intentionally target specific conditions.”
She also expected marketing to become more educational:
"As cannabis becomes more medically and socially accepted, I expect the demand for these products will only increase along with a need for educational marketing that focuses on translating the type of experience or effects a product will provide. An understanding of how the parts of this plant interact with our physiology both separately and together will enable consumers to choose products that truly benefit their specific needs—and when consumers can find a product that actually works for them, they will become loyal, lifelong customers."
Five years later: what happened
Happened. Demand for whole-plant products would push extraction methods that keep more of the plant's compounds.
The market moved toward extracts sold on keeping the plant's full chemical profile. Solventless extracts, made without chemical solvents, grew quickly after 2021 (see Walters above). Her expectation that plants would be bred to target specific conditions is covered under Weil's prediction and did not happen.
Brian Cusack: extraction rules in Ireland
Brian Cusack was, in 2021, the founder of Dr. Hemp Me
In 2021, Cusack said extraction was at the center of a regulatory dispute in Ireland. As the owner of an Irish CBD company, he described how the rules were affecting his products.
“In Ireland, the FSAI (Food Safety Authority of Ireland) are starting to crack down on CBD products that are extracted using CO2 and ethanol, which in truth is very damaging to the whole industry,” Cusack said. “The only extraction method which is allowed is cold-pressed, which is expensive and not very efficient.”
CO2 extraction, also called supercritical fluid extraction, is widely used for cannabis and hemp. It does not require high temperatures, which helps preserve heat-sensitive compounds such as terpenes.
A 2020 study in Scientific Reports found that “CBD and THC can be extracted with high efficiency from cured cannabis biomass using supercritical CO2 without a co-solvent.”
Cusack argued that Ireland's approach forced manufacturers to use less efficient extraction methods and limited the strength of the products they could sell:
"Although the EU does allow CO2 and ethanol which the FSAI should be abiding by they are for the moment pushing forward with cold-pressed only. This means high strengths will not be available as using cold-pressed on EU-approved hemp seeds will only allow a 5% strength maximum which is currently our lowest strength CBD oil and by far the least popular compared to the 10%, 20% and 30%. The Irish CBD industry is not lying though and all CBD companies in Ireland are beginning to fight this."
Our 2021 article predicted that regulators would relax these extraction rules once the science became clearer.
Five years later: what happened
Didn't happen. Regulators in Ireland would relax limits on CO2 and ethanol extraction.
Irish and EU regulators still treat CBD extracted with CO2 or ethanol as a novel food, which needs authorization before it can be sold as food. In a recall notice, the Food Safety Authority of Ireland described CBD oils as unauthorized novel foods because CO2 and ethanol extraction were used to make them.
As of May 2026, no CBD food product had received EU novel food authorization. EFSA's 2 mg per day provisional safe intake would limit the strength of any product that is approved.
What the research says in 2026
The entourage effect is still a hypothesis under study. Most of the evidence comes from laboratory and animal studies, and those studies do not agree with each other.
Several lab studies from 2019 to 2022 tested common terpenes, including myrcene, limonene, pinene, linalool, and beta-caryophyllene, at the cannabinoid receptors that THC acts on. A 2020 Frontiers in Pharmacology study found no meaningful activity from the terpenes alone or combined with THC or CBD, apart from a possible weak interaction between beta-caryophyllene and the CB2 receptor.
Other studies found interactions. In a 2021 University of Arizona study in mice, several terpenes activated the CB1 receptor and added to the pain-relieving effect of a synthetic cannabinoid. In a 2024 Johns Hopkins trial with 20 healthy adults, vaporized d-limonene reduced the anxiety caused by THC without changing THC's other effects.
The Johns Hopkins trial is one of the first controlled human studies of a terpene and THC interaction. It was small, tested one terpene, and needs to be repeated in larger groups. One of its authors advises a terpene company, and the university has filed a patent application based on the results.
True Blue sells terpene products for flavor and aroma. We do not claim that our terpenes treat or prevent any condition.
What the 2021 predictions got right and wrong
Of the 12 predictions we graded, 3 happened, 3 partly happened, 5 did not happen, and 1 is too early to grade. The experts were most accurate about products: demand for solventless and full-spectrum products grew, and entourage-effect language became common in marketing.
They were least accurate about regulation and consumer behavior. CBD and hemp rules became stricter in the US and the EU, isolate products kept a large share of the market, and high-THC flower still sells at a premium.
The science is also less settled than our 2021 article said. We plan to revisit these grades as new human research and regulatory decisions come out.