The Delta-9-THC content of cannabis has risen steadily for decades, and many consumers assume that a higher percentage automatically means a stronger experience. But a new High Times feature complicates that picture — with the help of a Swedish researcher who explains why the chase for high THC numbers can be misleading.
Five Milligrams Scored 34 out of 100 — Ten Milligrams Scored 39
In studies where healthy volunteers inhaled THC, participants rated their high on a 100-point scale. At 5 mg THC the average high landed at 34. When the dose was doubled to 10 mg, the score rose only to 39. In other words: 100% more cannabis delivered just 15% more high.
That is how Amir Englund, a researcher in cannabinoid psychopharmacology at the Institute of Psychiatry, Psychology and Neuroscience at King’s College London, summarizes a meta-analysis he and colleagues conducted on studies giving THC to healthy people who were mainly infrequent users.
“More THC is not necessarily going to give you more bang for your buck,” Englund told High Times. At the same time, he stresses that higher levels still affect the brain and the body’s CB1 receptors — the issue is not that potency is irrelevant, but that the relationship between dose and effect plateaus.
The Effect Plateaus
Englund describes a so-called dose-response curve that flattens early: at low doses more THC quickly produces more effect, but beyond a certain point additional THC yields ever-smaller extra highs. The explanation lies in how the body responds. The more THC binds to CB1 receptors, the more the brain withdraws those receptors — a downregulation. To compensate, the user must keep increasing the dose to reach the same effect, and eventually gets little more for their THC.
Englund also explains that the system is fluid: after two days off cannabis, the receptors start coming back. The problem, he argues, is that the market targets the very heaviest users — who account for up to 80% of all high-THC products but make up perhaps only 10% of everyone who uses cannabis. That creates a vicious cycle in which people take more THC than they need.
Potency a Polarizing Issue
The background is clear: according to a March 2025 article in the American Journal of Psychiatry, the average potency of herbal cannabis seized in the U.S. before 2000 was under 5% THC, while in most state-regulated nonmedical retail markets it is now around 20%. Over the past decade, very high-potency products have risen sharply — from infused flower with up to 60% THC to solvent-based concentrates with as much as 99% THC.
At the same time, figures from the Marijuana Policy Project show that in 2025 alone, legalized states generated more than $4.57 billion in cannabis tax revenue from adult-use sales — a record year.
More Voices in the Debate
Several researchers are cited in the feature. Ryan Vandrey at Johns Hopkins warns that as THC levels are pushed up and CBD disappears, it becomes harder for consumers to fine-tune their dose, risking an overshoot. Duncan Mackie at Bud & Mary’s points out that when a plant overexpresses THC it “drowns out” signals from other cannabinoids and terpenes that actually contribute to the experience.
Russ Hudson, a cannabis phytochemist in Texas, argues that the feeling of being “stoned” often has nothing to do with THC at all but with terpenes like myrcene and humulene — and that a sole focus on the THC number gives an incomplete picture.
The Future: Chemical Profile Instead of Percentage
Kevin Hill, professor of psychiatry at Harvard Medical School, meanwhile warns that polarization around cannabis leads both advocates and opponents to spread incomplete or false messages.
Englund and colleagues also found in a 23-year Danish study that average potency nearly quadrupled — from just under 8% to over 30% — and that this was followed by more hospital visits for addiction and cannabis-induced psychosis, although one cannot establish that one caused the other.
The thinking going forward, according to several of the researchers, is that instead of chasing THC percentage, consumers will seek a specific chemical profile — high in certain terpenes or minor cannabinoids — rather than just a high number.
Source:
100% More THC = 15% Stronger High. So Why Did Weed Spend 30 Years Chasing the Number? — High Times (interview with Amir Englund, King’s College London)
Sponsor: Sensi Seeds are one of Europe’s most recognized names in premium cannabis genetics, offering a wide selection of feminized, autoflowering, CBD-rich and F1 hybrid seeds for customers who want quality, consistency and choice.