THC Potency in Confiscated Marijuana Rose From Under 1.5% in 1980 to 4.2% in 1997
Analysis of 35,312 confiscated samples showed U.S. marijuana THC rose from under 1.5% (1980) to 4.2% (1997) while CBD and other cannabinoids remained unchanged.
Potency research
Explore published research on potency, including study methods and limitations.
THC Was the Primary Active Ingredient in Marijuana While CBC and CBD Concentrations Made No Difference
Controlled study of 23 marijuana users found varying CBC and CBD concentrations did not change the effects of smoked marijuana, confirming THC as the primary active ingredient.
Higher THC Doses Caused Greater Cognitive and Motor Impairment in a Dose-Dependent Pattern
In 24 non-daily users, cognitive and motor impairment increased linearly with THC dose (up to 69 mg), but some individuals showed no motor impairment even at blood THC above 40 ng/mL.
Tracking the Rapidly Changing Synthetic Cannabinoids in "Spice" Products
Analysis of 140+ herbal incense products from 2008-2009 showed manufacturers rapidly switched synthetic cannabinoid ingredients in response to German bans, making contents unpredictable for consumers.
Could Changing the THC/CBD Ratio in Cannabis Reduce Its Harms?
A commentary argued for harm reduction through product composition changes, specifically reducing THC and increasing CBD in cannabis to lower psychosis and addiction risks.
Heavy high-potency cannabis smokers reported visual disturbances lasting months after quitting
Eight heavy high-potency cannabis-dependent smokers reported visual flashbacks including illusions and color distortions persisting 3-6 months after quitting.
What Australian police seizures reveal about cannabis potency and CBD levels
Analysis of 232 cannabis samples seized in Australia found high average THC (14.88%) and nearly absent CBD (0.14%), confirming global trends toward high-potency, low-CBD cannabis.
THC blood levels in impaired drivers increased 58% over a decade in Norway
THC blood levels in suspected impaired drivers in Norway rose 58% from 2000 to 2010, far outpacing increases in alcohol or amphetamine levels in similar drivers.
Women Rate Cannabis as More Rewarding Than Men — Even at the Same Dose
Women gave higher "Good" and "Take Again" ratings than men after smoking cannabis in controlled conditions, despite identical intoxication — suggesting sex-specific vulnerability to cannabis's reinforcing effects.
Non-smokers exposed to secondhand cannabis smoke tested positive for THC in blood and oral fluid for up to 3 hours
Non-smokers sealed in a room with cannabis smokers for one hour tested positive for THC in blood and oral fluid for up to 3 hours and reported feeling mild subjective effects.
Secondhand cannabis smoke rarely caused positive urine tests at standard cutoffs, but did at lower thresholds
Under extreme sealed-room conditions, secondhand cannabis smoke caused positive urine tests at 20 ng/mL cutoffs but rarely at the standard 50 ng/mL workplace threshold.
Room ventilation dramatically reduced secondhand cannabis smoke effects on cognition, mood, and drug test results
Ventilation at 11 air changes per hour eliminated all measurable secondhand cannabis effects (drug tests, sedation, cognitive impairment) that occurred under unventilated sealed-room conditions.
High-Dose Cannabis Disrupts the Brain's Error Detection System
EEG study found high-dose THC disrupted automatic error detection in frequent cannabis users, while even low doses impaired conscious error recognition.
High-Potency Cannabis Actually Impairs Creative Thinking
Controlled study found high-potency cannabis significantly impaired divergent thinking in regular users, while low-potency cannabis had no effect on creativity measures.
Seven New Cannabinoids Discovered in High-Potency Cannabis
Scientists discovered seven new cannabinoids in high-potency cannabis, with one showing higher CB1 binding and more potent THC-like effects than delta-8-THC.
U.S. Cannabis Potency Tripled Over Two Decades While CBD Nearly Vanished
Analysis of 38,681 DEA-seized samples showed cannabis THC tripled from ~4% to ~12% between 1995–2014 while CBD nearly disappeared.
Adolescent Dabbing Case Shows How High-Potency Cannabis May Speed Up Cannabinoid Hyperemesis Syndrome
A case report of an adolescent using dabs, THC edibles, and heavy smoking who developed severe cannabinoid hyperemesis syndrome raises concerns that high-potency products may trigger the condition faster and in younger users.
Twitter Analysis Reveals Mostly Positive Attitudes Toward Cannabis Edibles, With Some Warning Signs
Analysis of 100,000+ tweets found mostly positive attitudes toward cannabis edibles, but concerning reports of unpredictable effects, with more edibles discussion in states where cannabis is legal.
How Long Cannabis Stays in Your Blood Depends on How You Consume It
Controlled trial shows smoking and vaping deliver cannabis identically to blood, identifies potential biomarkers for recent use, and proposes detection cutoffs under 8 hours.
Young Adults in Colorado Judge Cannabis and Tobacco Harms Through Five Key Lenses
Qualitative study of 32 young adults in Colorado found they evaluate cannabis and tobacco risks through five lenses: combustion, potency, chemicals, addiction type, and information sources.
Inside Washington State's Legal Cannabis Market: THC Levels, Prices, and the Rise of Concentrates
Analysis of 44 million legal cannabis purchases in Washington found concentrates growing rapidly (146%) with 68.7% average THC, while consumers consistently paid premiums for higher potency.
Eating Cannabis Produces Much Lower Blood THC Levels Than Smoking, with Effects Peaking at 1.5-3 Hours and Lasting 6-8 Hours
Controlled study found oral cannabis produced much lower blood THC levels than inhalation, with effects peaking at 1.5-3 hours and lasting 6-8 hours, complicating drug testing for edible users.
Some hemp seeds contain far more THC than the legal limit allows
Lab testing found consumer hemp seeds contained up to 1,250% more THC than Canada's legal limit, with potential for 3.8 mg THC exposure from a daily serving.
Not all high-CBD cannabis extracts work the same, despite having identical CBD levels
Profiling 94 phytocannabinoids across 36 strains showed that high-CBD extracts with equal CBD content produced different anticonvulsant effects, proving THC/CBD ratios alone are insufficient.
Low-Dose THC Improved Memory in Aging Mice. Higher Doses Impaired It in Young Ones.
THC impairs cognition in young brains but animal research shows very low doses may restore memory and protect against neurodegeneration in aging brains — a biphasic dose-response.
College students who vaped cannabis were influenced by peers who also started vaping, not just peers who used any cannabis
Among 1,313 college freshmen, 5.9% started vaping cannabis during their first year, driven specifically by peers who also started vaping cannabis rather than general cannabis or e-cigarette users.
Oral fluid THC tests were highly accurate at detecting cannabis use but poor at measuring blood THC levels
Analysis of 4,596 drivers found oral fluid THC tests were 79% sensitive and 98% specific for detecting cannabis use, but poorly predicted actual blood THC levels.
A survey of 1,722 cannabis growers found 44% used chemical fertilizers, with hydroponic growing as the key predictor
Survey of 1,722 cannabis growers found 44% used chemical fertilizers or insecticides, with hydroponic growing as the key predictor. Poor product labeling made it hard to identify harmful chemicals like plant growth regulators.
Among LA tenth-graders, 31% had tried smoking cannabis, 21% had tried edibles, and most users consumed via multiple methods
Survey of 3,177 LA tenth-graders found high cannabis use across methods (31% combustible, 21% edible, 11% vaporized), with most users consuming via multiple administration methods.
Cannabinoid Hyperemesis Syndrome: Why Standard Anti-Nausea Drugs Fail and What Works Instead
Review explains why standard anti-nausea drugs fail in cannabinoid hyperemesis syndrome and why benzodiazepines, antipsychotics, and topical capsaicin work better, based on the condition's unique pathophysiology.
French Cases of Cannabinoid Hyperemesis Matched the International Pattern
Analysis of 29 French CHS cases alongside 113 international cases confirmed a consistent pattern: young male daily cannabis users with cycling vomiting relieved by hot showers but not standard antiemetics.
Illicit Cannabis Extracts Used for Childhood Epilepsy Had Wildly Inconsistent Content
Chemical analysis of cannabis extracts used by 41 Australian families for childhood epilepsy found wildly inconsistent cannabinoid content, with most samples low in CBD and high in THC, contrary to parents' beliefs.
Schizophrenia Patients Accepted Low-THC Cannabis but Preferred Their Regular High-Potency Product
Pilot study found schizophrenia patients accepted low-THC cannabis variants but preferred their usual high-potency product, supporting the feasibility but highlighting challenges of cannabis substitution.
Cannabis hyperemesis patients had similar hair THC levels as recreational users without vomiting
Hair analysis found cannabis hyperemesis patients had similar THC levels as recreational users without symptoms, suggesting the condition is idiosyncratic rather than purely dose-dependent.
High-concentration cannabis products are sending more young children to the hospital
A review found increasing pediatric hospitalizations from high-potency cannabis products like edibles, causing sedation and respiratory depression in young children, while chronic teen use causes cognitive and GI problems.
Cannabis Got Stronger Again: THC Doubled From 2008 to 2017 and Concentrates Exploded
Follow-up potency monitoring found cannabis THC doubled to 17.1% by 2017, concentrates hit 55.7%, and the THC:CBD ratio reached 104:1 in both U.S. and European markets.
Daily High-Potency Cannabis Use and Psychosis Risk: The Largest European Study Drew a Direct Line
Across 11 European cities, daily high-potency cannabis use was linked to ~5x higher odds of first-episode psychosis, with population impact varying by local market potency.
European Cannabis Got Stronger and Cheaper Per Milligram of THC Over a Decade
Across 30 European countries, cannabis resin potency doubled while cost per milligram of THC dropped from 2006 to 2016 — users got more THC for less money.
Utah EVALI investigation: 92% of hospitalized patients had used THC vaping products
Utah EVALI investigation found 92% of patients used THC vaping products, with vitamin E acetate detected in 89% of tested THC cartridges.
Breath testing can reliably detect THC throughout the 3-hour impairment window after smoking cannabis
Controlled study shows breath THC testing reliably detects cannabis use during the 3-hour impairment window, with kinetics closely tracking blood levels.
Cannabis terpenoids enhanced cannabinoid anti-cancer effects, but only when naturally co-occurring in the same strain
Study of 17 cannabis strains found terpenoids enhanced cannabinoid anti-cancer activity only when naturally co-occurring in the same strain, supporting strain-specific entourage effects.
Your dispensary's strain names are genetically unreliable
Genetic analysis found no basis for sativa/indica/hybrid labels and significant inconsistencies in the same strain from different dispensaries.
When choosing cannabis, consumers prioritize price, but medical users prioritize CBD content
Consumer choice experiments showed medical cannabis users prioritize CBD content while recreational users and non-users prioritize price. Some warning messages paradoxically increased appeal.
Low-dose CBD enhanced THC intoxication while high-dose CBD reduced it, especially in infrequent users
A controlled trial found low-dose CBD enhanced THC intoxication while high-dose CBD reduced it, with the strongest effects in infrequent cannabis users.
Landmark study identified vitamin E acetate as the primary toxicant behind the 2019 vaping lung injury outbreak
A CDC/NEJM study found vitamin E acetate in 94% of EVALI patients' lung fluid across 16 states, with 94% of patients linked to THC vaping, identifying the primary toxicant behind the 2019 vaping lung injury outbreak.
THC Interacts With Common Medications in Ways Most Users and Doctors Don't Know About
THC interacts with common medications through shared liver enzymes (CYP3A4, CYP2C9), and genetic variants in up to 35% of Caucasians increase THC bioavailability.
Critical analysis challenges the scientific basis for the cannabis "entourage effect"
A critical review found that the cannabis "entourage effect," widely used to market whole-plant products, rests on poorly defined and largely unsubstantiated pharmacological claims, with the original literature commonly overinterpreted.
Cannabis concentrates impaired movement speed and balance in frequent users, with effects lasting at least an hour
Study of 65 frequent concentrate users found dabbing impaired arm speed for at least 1 hour and balance immediately, with motor impairment poorly correlated to blood THC levels.
Major London study: one-quarter of new psychosis cases attributed to high-potency cannabis
Landmark GAP study of 410 first-episode psychosis patients found 25% of new cases attributable to high-potency cannabis, with genetic and environmental factors acting together.
Frequent cannabis users can have blood THC above legal driving limits even after days of abstinence
Systematic review found frequent cannabis users can exceed legal THC driving limits (2 or 5 ng/mL) after days of abstinence, challenging per se laws.
Dual cigarette and e-cigarette use was the strongest predictor of marijuana vaping initiation in young adults
Prospective study of 2,327 college students found dual cigarette/e-cigarette use predicted marijuana vaping initiation, while vape shop social networks predicted escalation.
A long-time marijuana user developed psychosis only after switching to high-potency "dabs" with up to 80% THC
Case of a long-time marijuana user who developed paranoid psychosis within one month of switching to "dabs" with up to 80% THC.
Oral cannabis at 25-50 mg THC markedly impaired cognition in infrequent users, with delayed onset and peak effects
Controlled study found oral cannabis at 25-50 mg THC markedly impaired cognition in infrequent users, with effects delayed 30-60 min and peaking at 1.5-3 hours.
CB1 receptor antagonists could provide a targeted treatment for cannabis overdose, similar to naloxone for opioids
Review proposes CB1 receptor antagonists as a cannabis overdose antidote, similar to naloxone for opioids, noting most overdose symptoms are CB1-mediated.
Cannabis edibles produced delayed, lower blood THC peaks than smoking, with women showing higher concentrations
Controlled study of cannabis brownies found blood THC peaked at 1.5-2 hours, women had higher concentrations, and oral fluid testing reflected oral deposition, not blood levels.
A precision cannabis inhaler allowed hospitalized patients to use far less cannabis while achieving pain relief
A metered-dose cannabis inhaler reduced daily consumption by 95% (1,000 mg to 51 mg) while providing significant pain relief and high satisfaction in hospitalized patients.
Eight minor cannabinoids showed activity at CB1 and CB2 receptors in cells and produced cannabinoid-like effects in mice
A comprehensive study of 8 phytocannabinoids found partial agonist activity at CB1 and/or CB2 receptors for multiple minor compounds, with several producing cannabinoid-like behavioral effects in mice.
After Legalization, Cannabis Got Stronger, ER Visits Rose, and Risk Perception Dropped
Review found legalization increased cannabis potency and ER visits while decreasing risk perception, arguing for health-focused regulation beyond market economics.
Most light cannabis products sold in Italy contained pesticides and metals exceeding safety limits
Analysis of 31 light cannabis products from Italy found 87% contained pesticides and multiple heavy metals exceeding safety limits, highlighting the need for cannabis-specific regulations.
Blood THC levels don't reliably predict whether someone is too impaired to drive
In a simulated driving study of 14 people, legal THC blood limits failed to correctly predict impairment. Nearly half exceeded the limit without being impaired, while over half were impaired when THC levels had dropped below the cutoff.
Delta-8 THC products are widely sold as legal hemp but raise serious safety and regulatory concerns
Delta-8 THC is chemically similar to standard THC but sold unregulated in gas stations and online. The lack of safety standards has led to poisoning reports, including pediatric emergencies with children arriving unconscious.
Most cannabis driving research uses products far weaker than what people actually buy, creating a major evidence gap
Almost all cannabis driving research uses ~6% THC products, while consumers buy flower at 20%+ THC and concentrates above 60%. This gap means the true impact of modern cannabis on driving may be significantly underestimated.
Inside Washington's Legal Cannabis Market: Extracts Took Over, Prices Fell, and THC Per Dollar Soared
Analysis of 110M transactions in Washington's legal market showed extracts growing to 28.5% of sales, with falling THC prices and dabs dominating the concentrate category.
U.S. Cannabis Potency Update Through 2019: THC Rose, Then CBD Made a Comeback
Third potency monitoring report: THC continued rising through 2019, but the THC:CBD ratio suddenly reversed as CBD products entered the market post-2018 Farm Bill.
Current cannabis product labels may not effectively communicate THC dose to consumers
Policy review found that cannabis product labels in regulated markets often fail to help consumers understand THC dose, and proposed five principles for more effective labeling.
Cannabis-induced psychosis rates more than doubled in Denmark from 2006 to 2016
Danish national registry data showed cannabis-induced psychosis incidence more than doubled from 2006-2016, while alcohol-induced psychosis declined and other substance-induced psychoses remained stable.
Blood and oral fluid cannabinoid levels varied widely between frequent and occasional cannabis smokers
Study of 191 cannabis users found blood THC per se limits performed poorly at detecting recent use, with oral fluid THC at 10 ng/mL showing the best but still imperfect performance.
A new class of synthetic cannabinoids proved exceptionally potent and was linked to deaths
New generation synthetic cannabinoids with alkene modifications showed up to 10x the potency of previous compounds and were found in 25 forensic cases including deaths and impaired driving.
Does daily high-potency cannabis use lead to more psychotic symptoms?
Large EU-GEI study finds daily high-potency cannabis use associated with the most severe positive psychotic symptoms in a dose-response pattern, while cannabis use was linked to fewer negative symptoms.
Rat study finds high-THC cannabis smoke impairs working memory but not attention, while high-CBD smoke does not
A rat study found high-THC cannabis smoke impaired working memory but not attention, while high-CBD smoke caused no cognitive deficits.
International expert consensus finds converging evidence that cannabis increases psychosis risk, especially at higher doses and younger ages
An international expert consensus concluded cannabis is a component cause of psychosis with dose-response and age-response relationships, but alone is neither necessary nor sufficient.
Where THC acts in the brain depends on dose and how many cannabinoid receptors are present
Meta-analysis of 372 participants found THC's brain effects are dose-dependent and track with CB1 receptor density across regions.
Most CBD products contain undisclosed THC, including some labeled "THC-Free"
Lab testing found THC in 65% of 80 CBD products, including 24% of those labeled "THC-Free," with concentrations up to 2 mg/mL.
Nearly half of CBD products tested had inaccurate labels
Nearly half of 80 CBD products tested had CBD concentrations more than 10% off their labels, with some containing less than half the advertised amount.
Even frequent cannabis users show psychomotor impairment right after use, but recover within an hour
Frequent cannabis users showed peak psychomotor impairment immediately after smoking but recovered significantly within one hour, replicated across two studies.
Detailed look at what medical cannabis products patients actually buy in New York
Study characterized actual medical cannabis product purchases in New York State, providing rare objective data on patient product selection in a regulated market.
Not All High-THC Cannabis Extracts Are Equal for Cancer or Inflammation
Lab testing of 25 high-THC cannabis extracts found huge variation in anti-cancer and anti-inflammatory effects, with specific terpenes like terpinene and p-cymene predicting better outcomes.
Why Edible Cannabis Products Are Especially Risky for Children and Teens
Review described how edible cannabis products pose unique pediatric risks due to food-like appearance, copycat packaging, lack of smell, and delayed onset that promotes overconsumption.
Fourth-Generation Synthetic Cannabinoids Are More Potent and Toxic Than Ever
At least 20 new fourth-generation synthetic cannabinoids emerged between 2017-2021 with higher receptor potency and increased adverse reactions including psychosis, self-harm, and deaths.
Half of Low-THC Cannabis Products in Switzerland Were Laced with Synthetic Cannabinoids
Swiss drug checking found half of low-THC cannabis samples were laced with synthetic cannabinoids, with users experiencing significantly more psychological and cardiac adverse effects.
U.S. Cannabis Markets Are Overshooting Therapeutic THC:CBD Ratios
Analysis of U.S. dispensary products found medical cannabis THC:CBD ratios are nearly identical to recreational products — most would produce significant intoxication rather than therapeutic benefit.
Oral cannabis produced higher urine drug test concentrations than vaporized cannabis
Controlled study of 21 people found oral cannabis produced positive urine tests 97.6% of the time versus 59.5% for vaporized cannabis at standard workplace cutoffs.
Cannabis strain labels like "indica" and "sativa" don't reliably predict chemical content
Analysis of commercial cannabis across 6 US states found strain names and indica/sativa labels do not reliably predict actual chemical content.
Measuring Exactly How Much THC You Actually Smoke: A New Field Testing Method
A portable potency tester combined with real-time tracking created the first practical standard THC unit measure — higher milligram doses correlated with greater intoxication.
Delta-8 THC: The Legal-Loophole Cannabinoid That's Booming with Minimal Research
Delta-8 THC boomed after the 2018 Farm Bill accidentally legalized it, but this scoping review found almost no human safety data behind the millions of products being sold.
THC in Rome's Hashish Nearly Doubled in 7 Years — From 13.7% to 27.1%
Rome police seizures show hashish THC nearly doubled from 13.7% to 27.1% in seven years, with some samples exceeding 40% — and young males are the primary users.
Delta-8 THC Is Already Showing Up in 1 in 4 Positive Workplace Drug Tests
One in four positive workplace drug tests now contain delta-8 THC metabolites — 11% from delta-8 exclusively — creating new challenges for testing programs and employees alike.
High-potency cannabis use predicted psychosis risk independently of genetic predisposition
Two large studies found daily high-potency cannabis use carried 5x psychosis risk independently of genetic predisposition, and schizophrenia genetics did not predict heavy cannabis use.
Cannabis industry uses familiar tactics from tobacco and alcohol to fight THC potency regulation
Analysis of cannabis industry testimony in Washington State identified three rhetorical strategies against THC potency regulation: threatening economic harm, distracting from the issue, and discrediting the science, mirroring tactics used by tobacco and alcohol industries.
Community and professional stakeholders support taxing high-THC products, but industry opposes
Legislature-mandated study in Washington found community and professional stakeholders favor THC-based taxation and age restrictions for high-potency cannabis, while industry advocates oppose taxation and prefer education-only approaches.
10 Years of U.S. Cannabis Potency by Region: THC Keeps Climbing Everywhere
10-year DEA analysis shows cannabis THC rising across all U.S. regions with virtually no other cannabinoids present — legal and illegal markets have converged on THC monoculture.
Survey of HHC users found they used it about 10 days per month, mostly for anxiety and pain, with some reporting withdrawal
First systematic survey of 109 HHC users found frequent use (~10 days/month) primarily for anxiety and pain, with 17% reporting adverse effects and 20% of quitters experiencing withdrawal symptoms.
CBD did not reduce THC side effects and actually increased THC blood levels and psychoactive effects in a clinical trial
A rigorous crossover trial of 37 volunteers found high-dose CBD increased THC blood levels by 118%, boosted "Feeling High" by 60%, and did not improve pain relief, contradicting the assumption that CBD reduces THC effects.
High-potency prenatal cannabis exposure linked to lower birth weight and shorter length in low-risk pregnancies
A controlled study found high-potency prenatal cannabis exposure (198 mg THC/day average) reduced birth weight and length, with female newborns showing smaller head circumference.
Jamaican cannabis THC levels surged from 1% to over 10% between 2014 and 2020
Analysis of 299 Jamaican cannabis samples found THC potency surged from 1.1% to 10.2% between 2014-2020, with THC-to-CBD ratios increasing from 2:1 to nearly 200:1.
Delta-8 THC was available at about 1 in 10 tobacco and hemp retailers in Fort Worth, even amid legal uncertainty
Survey of Fort Worth retailers found Delta-8 THC available at ~10% of licensed locations, concentrated in tobacco and hemp shops, with no decline despite ongoing legal challenges.
Rising THC Potency Linked to More Cannabis-Related Diagnoses in Germany
A German study found rising THC potency was associated with more cannabis-related psychiatric diagnoses across all 16 federal states, with men affected more than women.
Cannabis-Psychosis Link Was 11 Times Stronger in Adolescents Than Young Adults
A study of 11,363 Ontario youth found cannabis use was associated with 11-fold psychosis risk during adolescence but no significant risk during young adulthood.
What Half a Million Cannabis Products Look Like on a Major Online Marketplace
Analysis of 500K+ cannabis product listings from Weedmaps found THC dominates, 42% feature flavor marketing, and multisystem delivery methods are most common.
Cannabis Use Explains Little of the Higher Psychosis Risk in European Ethnic Minorities
EU-GEI study across five European countries found cannabis use explained very little of the elevated psychosis risk among ethnic minorities, except in two specific subgroups.
Three Novel Synthetic THC Analogs Identified in European Consumer Products
Three novel semisynthetic THC analogs found in European products marketed as "CB9," "tresconol," and "CBx." No safety data exists for any of them.
Year-long tracking of synthetic cannabinoids in Mayotte showed rapidly shifting and consolidating market
Year-long monitoring of synthetic cannabinoids in Mayotte identified 13 different compounds across 195 street samples, revealing a market that consolidated under dominant suppliers but whose specific products changed dramatically between monthly campaigns.
Review: four years of cat-and-mouse chemistry as manufacturers evade China's synthetic cannabinoid ban
A review of four years since China's 2021 synthetic cannabinoid ban documents at least six chemical strategies manufacturers use to evade the legislation, including a DIY synthesis approach that converts legal precursors into potent banned compounds.
Higher potency cannabis flower linked to more frequent use and greater addiction risk in California young adults
A study of 512 California young adults found each increase in cannabis flower potency was associated with 3.3 more use days per month and higher addiction scores, contradicting the assumption that people use less of stronger products.
How the body processes a hemp-derived product containing both raw and activated cannabinoids
A controlled study found raw cannabinoids (CBDA, THCA) achieved 19-25x higher blood levels than activated forms (CBD, THC), and even 7.2mg of THC in a full-spectrum product caused noticeable intoxication.
Researchers identify a dose threshold for delta-8 THC toxicity in young children
Analysis of 232 pediatric delta-8 THC ingestions found a dose of 1.7 mg/kg identified 98% of cases progressing to severe toxicity, establishing the first clinical reference threshold.
Six distinct cannabis user profiles reveal that using many product types may matter more than frequency alone
Six cannabis user profiles were identified in Washington State, with polymodal users (multiple product types) reporting more adverse events than even the most frequent single-product users.
Cannabis flower products frequently overstate THC potency on labels while concentrates are more accurate
Independent testing of 277 Colorado cannabis products found flower THC labels are frequently inflated (only 57% accurate), while concentrate labels are much more reliable (96% accurate).
Most Cannabis Edibles Contain 100+ mg THC and Use Child-Appealing Marketing
Analysis of 2,282 cannabis edibles found most contained 100+ mg THC, with widespread use of child-appealing characters, colors, and flavors.
Warning Labels on Delta-8 THC Products Increased Youth Awareness of Intoxication and Harm
Experiment with 3,647 adolescents found warning labels on delta-8 THC products increased perceived risk and intoxication but did not reduce use susceptibility.
German Cannabis Patients Use Much Higher THC Doses Than Expected
Survey of 1,030 German cannabis patients found flower users consumed an average of 336 mg THC daily, nearly 20x more than those using other preparations, with implications for driving safety.
What Every Parent Should Know About Teens and Cannabis in 2025
Teen cannabis use has held steady despite legalization, but ER visits, child ingestions, and product potency have all increased—changing the risk landscape.
Most CBD Products Contain Undisclosed Minor Cannabinoids
Lab analysis of 80 CBD products found all contained CBDV, most contained CBG, CBC, CBN, and CBDA at widely varying concentrations not disclosed on labels.
Legalizing Smokable Medical Cannabis in Florida Sharply Increased THC Per Patient
After Florida legalized smokable medical cannabis, weekly THC dispensed per patient increased 42% and continued rising, exceeding recommended daily dose thresholds.
THCV Can Either Mimic or Block THC Effects in Rats Depending on Dose
In rats trained to recognize THC, THCV partially mimicked THC at moderate doses (54.6% substitution) but blocked THC effects at higher doses, with an inverted U-shaped response pattern.
EFSA Sets Delta-8-THC as Equally Potent to Delta-9-THC, Establishes Group Safety Limit for Food
EFSA determined delta-8-THC is equally potent to delta-9-THC and set a combined safety limit of 1 microgram/kg body weight, finding many food products contain above-natural delta-8 levels.
Alpha-Pinene Does Not Counteract THC-Induced Memory Impairment in Humans
A double-blind crossover trial found alpha-pinene at three doses did not counteract any THC effects in 19 adults.
Treatment-Seeking Adolescents Use Multiple Cannabis Products Including Delta-8 and Delta-10 THC
Treatment-seeking adolescents used multiple cannabis products including delta-8 and delta-10 THC.
Systematic Review Finds High-Potency Cannabis Linked to Problem Use, But Evidence Is Very Low Quality
A systematic review of 42 studies found high-potency cannabis may be linked to problem use, but evidence was "very low" certainty across all health domains examined.
About 1 in 4 Cannabis Home Growers Used Chemical Additives, With Rates Declining Over Time
A survey of 11,479 cannabis growers across 18 countries found about 1 in 4 used chemical additives, but rates appear to be declining over the past decade.
We Still Don't Know Enough About THC to Set Fair Driving Laws
Cannabis driving laws are being set without adequate science—we need comprehensive THC pharmacokinetic data to connect blood levels to actual impairment.
Cannabis Flower Labels Consistently Overstated THC Content Compared to Independent Testing
Independent testing of 74 Colorado cannabis products found flower labels consistently overstated THC content, sometimes beyond the 15% legally allowed variance.
Older Daily Cannabis Users Consumed Less THC and Fewer Concentrates, but Had Similar Disorder Rates Per Dose
A survey of 4,134 daily cannabis users found older adults used less potent products, but their risk of cannabis use disorder per milligram of THC was similar to younger users.
Delta-9 THC Users Had 20 Times the Odds of Also Using Delta-8 THC
A survey of 166 young adults found that Delta-9 THC users had 20 times the odds of also using Delta-8, with complex and sometimes contradictory risk perception patterns.
Australian Street Cannabis Averaged 12% THC With Almost No CBD, and Users Could Not Gauge Potency
Testing of 127 Australian street cannabis samples found average 12% THC with almost no CBD, and users could not accurately judge potency from their experience.
SUD Treatment Patients Mostly Smoke Cannabis Flower but THC Content Drives Their Product Choices
Survey of 472 SUD treatment patients found cannabis flower dominates use patterns, with THC potency driving purchases, though some chose CBD for perceived medical benefits.
Medicinal Cannabis THC Concentrations Were Higher After Psychosis Than Before in Australian Patients
Australian early psychosis service found medicinal cannabis THC concentrations nearly doubled in prescriptions written after psychosis onset, with 60% of patients experiencing attributed deterioration.
One-Third of NYC Young Adults Used Cannabis, With Edibles Surpassing Smoking as the Most Common Method
NYC longitudinal study found edible cannabis surpassed smoking as the most common method among young adults, with new users far outnumbering quitters.
Both Smoking and Eating Cannabis Damage Blood Vessel Function, JAMA Study Finds
JAMA Cardiology study finds both cannabis smoking and THC edibles impair blood vessel function comparably to tobacco, though through apparently different mechanisms.
Cannabis Concentrate Vaping Produces Substantial Toxic Byproducts
Review finds cannabis concentrate vaping produces significant toxic byproducts and some products contain hazardous additives, as research lags far behind market growth.
Researchers Warn of a Growing Epidemic of Drug-Induced Psychosis
A review warns that 30 years of rising methamphetamine and high-potency cannabis use have fueled a growing wave of drug-induced psychosis, with up to half of cases progressing to schizophrenia.
Cannabis Store Employees Care Less About THC Levels Than Their Customers Do
A Washington State survey found cannabis retail employees rated THC concentration as less important than customers, valuing terpene profiles and production methods more.
Nearly Half of Cannabis Users in This Survey Had Tried Semi-Synthetic Cannabinoids
Survey of 229 cannabis users found 44.5% had used semi-synthetic cannabinoids like Delta-8 THC and THCP, with adverse effects reported across all product types.
Does CBD Protect Your Memory When You Use THC?
THC impaired verbal memory as expected, but adding CBD in a 1:1 ratio didn't protect against the effect—challenging a popular harm reduction claim.
Delta-8-THC Can Cause Psychosis Despite Being Marketed as Milder Than Delta-9
Systematic review of case reports found delta-8-THC is associated with psychosis and mood symptoms in young adults despite being marketed as a milder, legal alternative to regular cannabis.
Cannabis Edible Brand Names Use Different Marketing Strategies for THC vs CBD Products
Analysis of 1,344 cannabis edibles found CBD brands use health/wellness themes (45%) while THC brands emphasize cannabis culture and food, potentially shaping consumer risk perceptions.
How Cannabis Triggers Psychotic-Like Experiences in Otherwise Healthy People
Systematic review of 38 studies finds high-potency cannabis, genetic predisposition, and environmental stressors interact to drive psychotic-like experiences in otherwise healthy people, with evidence of a bidirectional relationship.
Major Review: High-THC Cannabis Products Tied to Psychosis and Addiction, Mixed Results for Anxiety and Depression
Annals of Internal Medicine review of 99 studies (221K participants) finds high-THC cannabis consistently associated with psychosis and addiction, with mixed results for anxiety and depression depending on therapeutic context.
Inside India's Unregulated Cannabis Market: A 13-Year User's Call for Safety Testing
Drawing on 13 years in India's prohibited cannabis market, a researcher argues the real risks come from unregulated product contamination and unpredictable potency, not cannabinoids themselves.
What's Actually on Delta-8 THC Product Labels? A Packaging Analysis
Analysis of 140 delta-8 THC products found most lack health warnings and many don't clearly state cannabinoid content, highlighting gaps in an unregulated market.
Higher THC Proportion in Cannabis Predicted More Dependence and Anxiety, Regardless of Gender
Study of 202 trauma-exposed cannabis users found THC proportion (not THC:CBD ratio) predicted dependence and anxiety, with no gender differences in this association.
What We Don't Know About Vaping THC Liquids Could Be Dangerous
Review reveals zero human studies exist on the pharmacology of vaping THC liquids — despite widespread use and higher potency than smoked cannabis — highlighting urgent research and regulatory needs.
The Rise of Semi-Synthetic Cannabinoids in Europe
Over 30 semi-synthetic cannabinoids derived from hemp CBD are circulating in Europe with unknown safety profiles, posing challenges for regulation and detection.
The Link Between Teen Cannabis Use and Psychological Distress Strengthened From 2013 to 2023
Over a decade, the teen cannabis-distress link grew stronger, especially for frequent female users, while overall teen use declined.
Despite increasing cannabis potency in Europe, the severity of emergency department visits for cannabis toxicity stayed the same over 10 years
Ten-year European data from 40 EDs shows cannabis toxicity severity stayed stable despite increasing potency.
Long-Term Cannabis User Developed Rare Delusional Skin Infestation
Case report of a daily cannabis user who developed delusional infestation -- believing parasites were under his skin -- highlighting an unusual presentation of cannabis-associated psychosis.
THC at concentrations found in drivers' blood caused neurotoxicity through oxidative stress in lab cells
THC at concentrations found in the blood of traffic accident drivers caused dose-dependent neurotoxicity in human neuronal cells, including oxidative stress, mitochondrial damage, and early cell death signals.
Testing 11 New Synthetic Cannabinoids: Most Were More Potent Than THC
Rodent testing of 11 DEA-flagged synthetic cannabinoids found most significantly more potent than THC, with indazole and indole classes showing the highest potency.
A simple "how many times per day" question may be better than detailed daily logs for measuring general cannabis exposure
Study of 1,090 cannabis users found a brief quantity-frequency question better predicted long-term THC metabolite levels, while detailed daily logs better predicted acute THC, offering guidance for research measurement.
A Faster Way to Detect Dangerous Synthetic Cannabinoids in Vape Liquids
Cell-based screening detected synthetic cannabinoid activity in 6 of 23 vape liquids faster and cheaper than chemical analysis, and flagged unexpected CB1-interfering substances in five others.
Teens in states with legal recreational cannabis were 45% more likely to start vaping it, with e-cigarette use being the strongest predictor
Nationally representative study of 19,000+ youth found recreational cannabis legalization linked to 45% higher odds of starting cannabis vaping, but e-cigarette use was the strongest predictor at 8x higher odds.
Teens often misread cannabis edible warning labels and find products that look like snacks less risky
Focus groups with 28 Washington teens showed they misinterpret cannabis edible warnings, ignore nutrition labels, and find snack-like products less risky.