THC and sperm: Impact on fertilization capability, pre-implantation in vitro development and epigenetic modifications
Global cannabis use has risen 23% since 2010, with 209 million reported users, most of whom are males of reproductive age. Delta-9-tetrahydrocannabinol (THC), the main psychoactive phytocannabinoid in cannabis, disrupts pro-homeostatic functions of the endocannabinoid system (ECS) within the male reproductive system. The ECS is highly involved in regulating morpho-functional and intrinsic sperm features that are required for fertilization and pre-implantation embryo development…findings suggest that THC may alter key morpho-functional and epigenetic sperm factors involved in fertilization and embryo development. This is the first study [since 1984 when Morishima noted the lower quality of zygote production and zygote division] to demonstrate that sperm exposed to THC in vitro negatively affects embryo quality following IVF
(D.I comment: Toxic Cannabis Industry and the Three Market Debacle – ‘Regulating’ psychotropic toxins of idiosyncratic unpredictability is a farcical shell game for the entire sector with an incredibly inadequate and often tokenistic effort toward ‘health’ practices. Words like ‘safe’ or ‘safety’ and cannabis products in same sentence is at best an oxymoron; at worst it is just indicative of the level of denial, willful ignorance, or plain cover-ups in the addiction for profit sector that is the ‘Cannabis Industry’.)
University of Bath researchers found seven vaporizers sourced from the US contained dangerous SC compound Hannah Harris Green Sun 6 Oct 2024
A new study from the University of Bath revealed that seven vaporizers claiming to contain cannabis actually contained a much more dangerous “synthetic cannabinoid” (SC) compound.
Earlier this year, the same lab published a study showing that over one in six vaporizers confiscated from schoolchildren across the UK also contained SCs.
Sam Craft, an author on both studies, says his team decided to investigate the contents of seven vapes that one person presented to a drug and alcohol service after experiencing strange effects.
The person “was an experienced cannabis smoker”, says Craft, and they had decided to switch to vaping because they thought it would be less harmful.
Analysis of the vapes revealed that all of them contained the SC 5F-MDMB-PICA. There are hundreds of different SCs – officially named with these letter-number combinations, and referred to colloquially as “K2”, “Spice” and other slang terms.
Unlike natural cannabis, they are frequently associated with severe negative outcomes, including seizures and fatal overdoses. In England and Wales, SCs were responsible for nearly half of unnatural prison deaths from 2015-2020.
SCs are also illegal in the UK and the US. Still, they are showing up in the unregulated US hemp market that emerged as the result of the 2018 Farm bill, which inadvertently legalized all cannabis-derived products containing less than .3% delta 9 THC, cannabis’s most well-known psychoactive component.
SCs are distinct from semi-synthetic cannabinoids, like THC-O, and sometimes HHC and Delta-8 THC, which can be made by combining natural cannabis extracts with synthetic materials, and which are legal in much of the US.
That doesn’t mean they are without risk, according to Michelle Peace, a professor in the department of forensic science at Virginia Commonwealth University. Peace’s lab has studied the contents of vapes seized from a person who was arrested after experiencing schizophrenia-like symptoms. Her lab found the vapes contained semi-synthetic cannabinoids like THC-O.
Jim Crotty, a former DEA deputy chief of staff, says that SCs are appealing to illicit manufacturers because they are incredibly cheap to make and to sell. Instead of growing fields, manufacturers can make SC vapes with packets of powders they buy online.
Crotty says these products could be appealing to “vulnerable populations with limited income like youth and unhoused people”, who might find legal dispensary products unaffordable.
It’s unclear how big this problem is, partly because consumers themselves are unlikely to know they are using contaminated products. Peace says most consumers will “walk into any store” and assume that someone has made sure whatever they are buying has been tested for safety. But there is not yet federal regulation for the legal hemp market – “nobody’s watching”, what manufacturers put in their products, says Peace.
Crotty adds that cannabis is an easy drug to fake, because it’s so unpredictable.
“It doesn’t fall neatly into any one of the drug categories, right? Because depending on the amount, the potency, the individual that’s using it, it could lead to different effects,” he explained, adding that cannabis can feel like a stimulant, a depressant, a hallucinogen, or a little bit of all three.
Craft says that SCs can seem similar to natural cannabis, especially in very small doses, like in the vaporizers they studied. But, he said, the risk of “cardiovascular problems, the lack of consciousness and the acute psychotic symptoms are going to be far higher”.
At the moment, it is very difficult to tell if unregulated hemp products are labeled accurately in the US. Peace says that if you live in a state with legal recreational cannabis, you are much safer buying products from an authorized dispensary, although these are not entirely without risk either.
Legal and industry efforts are under way to bring safety standards for currently unregulated hemp products at least up to par with the state-legal cannabis industry. The Cannabinoid Safety and Regulation act, introduced in Congress in September, would empower the FDA to regulate hemp products.
Some cannabis brands are taking it upon themselves to ensure products only contain what they say they do.
The recreational cannabis brand Wana launched a direct-to-consumer platform that sells vetted hemp products, and also educates consumers on what products are safe.
“We apply the same rigor of testing, transparency and ingredients to the hemp side as we are to the regulated markets,” says Joe Hodas, the Wana CEO. But, he says, “it’s a tough and lonely road”, in a side of the industry that seems largely unconcerned with safety.
The Supreme Court is considering a case involving truck driver Douglas Horn, who was terminated after a drug test revealed THC in his system, despite using a product he believed to be THC-free. Horn has taken legal action against the product’s manufacturer, Medical Marijuana Inc., under the federal Racketeer Influenced and Corrupt Organizations Act (RICO), arguing that he suffered a business injury. During oral arguments, several justices appeared inclined to allow Horn to proceed with his claim, focusing on whether he meets the RICO requirement of being injured in business or property. The outcome could redefine how consumers seek redress against misleading product claims, particularly in the burgeoning cannabis industry.
Horn’s case originated when he began using a “wellness product” named Dixie X, advertised as containing zero THC. After failing a mandatory drug test, Horn independently verified the product did contain THC, leading to his dismissal. The court’s decision could send the case back to lower courts for further proceedings, potentially setting a precedent for similar disputes involving cannabis-related products. For additional details, visit New York Times.
The recent amendment to Victorian driving laws, set to take effect March 1, marks a significant shift in how medicinal cannabis users who test positive for THC while driving will be treated under the law. While proponents celebrate this as a victory for medical cannabis patients, serious concerns about road safety emerge from extensive research on cannabis impairment and driving ability.
Under the new legislation, magistrates will have discretionary power when dealing with drivers who test positive for THC (tetrahydrocannabinol) if they hold a valid prescription for medicinal cannabis and appear unimpaired. This changes the previous mandatory six-month licence suspension and fine system. However, driving with THC present in one’s system remains an offence.
The complexity of THC impairment presents significant challenges for road safety. Unlike alcohol, where blood alcohol concentration correlates strongly with impairment levels, THC’s effects are far more variable and complex. Research from the Colorado Department of Public Health and Environment shows that driving impairment can persist for at least six hours after smoking cannabis, even with doses as low as 18mg of THC. However, typical cannabis consumption often involves much higher doses – a standard joint containing 400mg of flower with 15% THC concentration can deliver around 60mg of THC, potentially extending impairment duration significantly.
Recent research published in Scientific Reports (2021) raises particular concern about cannabis users’ visual function and self-perception of impairment. The study found significant adverse effects on all visual parameters analysed, including visual acuity, contrast sensitivity, stereoacuity, and night-vision disturbances. Crucially, the research revealed that cannabis users may be unaware of their visual impairment, creating a dangerous situation where drivers might feel capable of driving while actually experiencing significant visual degradation.
Data from jurisdictions with longer histories of cannabis law reform provide sobering insights. Colorado’s Department of Public Safety reported that 66.3% of DUI case filings in 2018 tested positive for cannabinoids, with nearly half having THC levels at or above 5ng/mL, their legal limit. Studies from Washington State showed that cannabis-involved fatal crashes doubled after legalisation, increasing from 9% to 19%.
The Canadian perspective, detailed in research by the Traffic Injury Research Foundation, highlights how THC impairs crucial driving skills including:
Speed control
Lane positioning
Reaction time
Divided attention
Route planning
Decision-making
Risk assessment
The argument that regular medicinal users develop tolerance to THC’s impairing effects is problematic. While some studies suggest partial tolerance development, research indicates that when tolerance occurs, users typically increase their dosage to achieve desired effects, potentially maintaining or even increasing impairment levels.
Furthermore, a 2024 study from Massachusetts General Hospital revealed that THC significantly disrupts the prefrontal cortex’s normal connections and activity – the brain region crucial for decision-making and self-control. This disruption was measurable and correlated with intoxication severity, potentially affecting drivers’ ability to respond to changing road conditions.
The new Victorian legislation creates a challenging situation for law enforcement. How will officers determine whether a THC-positive driver is truly unimpaired? The research consistently shows that subjective self-assessment of impairment is unreliable, with users often underestimating their level of impairment.
While the law change aims to protect legitimate medicinal cannabis users from unfair penalties, it may inadvertently create a dangerous precedent. Australia’s successful road safety record has been built on clear, evidence-based policies regarding impaired driving. Introducing subjective assessment of impairment for THC-positive drivers could compromise these standards and potentially lead to increased road safety risks.
The evidence suggests that any THC presence while driving poses potential risks to public safety, regardless of its source or legal status. As this legislative change takes effect, careful monitoring of its impact on road safety will be crucial, as will continued research into reliable methods for assessing cannabis impairment in drivers.
The cannabis landscape has undergone a dramatic transformation over the past four decades, one that fundamentally changes the nature of the discussion around legalisation and youth access. This isn’t merely about policy changes – it’s about the substance itself. Cannabis potency has increased exponentially, from approximately 1% THC content in the 1980s to modern strains exceeding 20% THC, with some concentrates surpassing 90% THC. This remarkable increase in potency, driven by selective breeding and advanced cultivation techniques, raises profound questions about the applicability of historical cannabis research to current policy decisions.
Before delving into the policy implications, it’s crucial to understand what we’re dealing with. Cannabis contains numerous chemical compounds called cannabinoids, with tetrahydrocannabinol (THC) being the primary psychoactive component. THC interacts with the brain’s endocannabinoid system, influencing mood, perception, and various cognitive functions. Another major cannabinoid, cannabidiol (CBD), is non-psychoactive and has attracted attention for its potential therapeutic benefits.
Evidence from Recent Research
The recent study published in Psychological Medicine provides some of the most compelling evidence to date regarding youth cannabis use and mental health outcomes. The methodology was robust:
Population-based survey data from over 11,000 Ontario youths
Linked health service records including hospitalisations, emergency department visits, and outpatient visits
Data from Canadian Community Health Survey cycles (2009-2012)
Careful exclusion of respondents with pre-existing psychotic disorders
The findings are stark: adolescent cannabis users showed an elevenfold higher risk of developing psychotic disorders compared to non-users. Perhaps most telling is that approximately 5 in 6 teens who required hospitalisation or emergency department visits for psychotic disorders had previously reported cannabis use.
Recreational Cannabis Legalisation (RCL):
Significantly increased odds of past-month cannabis use
Overall odds ratio: 1.134 (95% CI = 1.116-1.153)
More pronounced effects in recent studies:
Adolescents: OR = 1.089 (95% CI = 1.015,1.169)
Young adults: OR = 1.221 (95% CI = 1.188,1.255)
The Gateway Effect: Beyond Rhetoric to Evidence
The gateway hypothesis has often been dismissed as oversimplified or politically motivated. However, the Christchurch Longitudinal Study provides compelling evidence that demands serious consideration. The study found that in 86% of cases where individuals had progressed to multiple illicit drug use, cannabis was their initial substance. This isn’t mere correlation – it emerged as the strongest risk factor for later involvement in other illicit drug use.
Supporting this finding, the University of Bristol’s research through the Population Health Science Institute found that regular and occasional cannabis use during adolescence is associated with significantly higher risks of other illicit drug use in early adulthood. This pattern suggests a developmental trajectory that policy makers cannot afford to ignore.
The Canadian Experience: A Natural Experiment
Canada’s experience with legalisation provides valuable insights into the challenges and consequences of cannabis policy reform. As noted by researcher André McDonald, the country’s move toward legalisation occurred “largely in the absence of solid evidence on the risks of cannabis use.” The subsequent finding that Canadian youth rank among the world’s heaviest cannabis users should serve as a cautionary tale for other jurisdictions considering similar policy changes.
Policy Implications and Public Health Considerations
The mounting evidence regarding cannabis use among youth presents policy makers with an urgent set of challenges that demand immediate attention. At the forefront of these considerations is the pressing need for potency regulation. Given the dramatic increase in THC content over recent decades, implementing strict controls on cannabis concentration has become critical. This extends beyond simple THC limits to encompass comprehensive product labelling requirements and the possibility of graduated concentration restrictions based on age groups – an approach that acknowledges the particular vulnerability of younger users while maintaining access for adults.
Access control mechanisms represent another crucial policy frontier. Current systems for age verification have proven insufficient in many jurisdictions, necessitating more robust approaches. The strategic placement of dispensaries, particularly their distance from schools and youth-centred facilities, requires careful consideration. Furthermore, the proliferation of online sales has created new challenges for ensuring youth cannot circumvent age restrictions, demanding innovative solutions that balance accessibility for legal users with protection for minors.
A critical yet often overlooked aspect of youth protection involves the systematic removal of what might be termed “passive permission models” from public spaces. These are environmental factors that inadvertently signal social acceptance or accessibility of cannabis to youth. This includes:
Visible storefront advertising near areas frequented by youth
Cannabis-themed merchandise or promotional materials in general retail settings
Public consumption areas visible from schools, parks, or youth centres
Social media content and advertising that may reach underage audiences
Cannabis industry sponsorship of public events or spaces accessible to youth
The Canadian experience, where youth cannabis use ranks among the world’s highest despite regulated legalisation, suggests that mere age restrictions are insufficient when broader environmental signals continue to normalise access.
Implementation requires a coordinated approach:
Strict zoning regulations that create cannabis-free zones around youth-centred spaces
Comprehensive advertising restrictions that go beyond direct product marketing
Digital safeguards against cannabis-related content reaching youth audiences
Community engagement programs to identify and address inadvertent permission signals
Regular audits of public spaces to ensure compliance and identify emerging concerns
This approach recognises that youth protection requires more than just legal barriers to access – it demands the creation of an environment that consistently reinforces non-use messages while eliminating subtle signals that might suggest otherwise.
The mental health implications of youth cannabis use, particularly the elevenfold increase in psychosis risk identified in recent research, necessitate a substantial expansion of mental health resources. Early intervention programs must be scaled up significantly, with specialised youth mental health services receiving particular attention and funding. Crisis response capabilities need enhancement to handle acute cases, while family support systems require strengthening to help parents and caregivers navigate the challenges of adolescent substance use.
Long-term Considerations
Looking beyond immediate policy needs, several long-term considerations emerge that require sustained attention and resource allocation. The educational infrastructure surrounding cannabis requires a complete overhaul to reflect current realities. Drug education programs, largely based on outdated information and approaches, must be updated to address the specific challenges posed by high-potency modern cannabis products. This education cannot stop with youth – parents, many of whom base their understanding of cannabis on their experiences with much lower-potency products from previous decades, need updated information about contemporary risks.
Healthcare system preparedness represents another critical long-term consideration. The increased prevalence of cannabis-related mental health issues among youth requires expanding mental health service capacity and addiction treatment resources. Prevention programs must evolve based on emerging evidence, while research funding needs to be allocated strategically to address critical knowledge gaps. The healthcare system must develop the capability to identify and intervene early in cases of problematic use, particularly among adolescents.
The regulatory framework governing cannabis must be designed with built-in flexibility to evolve as new evidence emerges. This includes developing sophisticated monitoring systems to track usage patterns and health outcomes, creating mechanisms for policy adjustment based on emerging data, and establishing effective enforcement strategies. Inter-jurisdictional coordination becomes particularly important as different regions experiment with varying approaches to legalisation and regulation.
Building a Safer Tomorrow
The evidence regarding cannabis legalisation and youth impact presents policy makers with a complex challenge that resists simple solutions. The demonstrated connection between recreational legalisation and increased youth use, combined with the significantly elevated risk of psychosis among teen users, demands a more nuanced and careful approach to cannabis policy than many jurisdictions have thus far implemented.
The data suggests a clear distinction between medical and recreational legalisation outcomes, with medical programs showing minimal impact on youth use while recreational legalisation correlates with significant increases. This disparity, combined with the unprecedented potency of modern cannabis products, creates a policy environment requiring sophisticated, evidence-based approaches that go beyond traditional regulatory frameworks.
As McDonald’s research emphasises, the precautionary principle must guide policy development, particularly given the stakes involved for youth mental health. The challenge lies not in choosing between prohibition and legalisation, but in developing regulatory systems sophisticated enough to protect vulnerable populations while acknowledging the reality of cannabis use in contemporary society.
Moving forward, success will require regulatory frameworks that effectively balance adult access with youth protection, supported by robust research programs and flexible policy mechanisms. The evidence demands nothing less than a comprehensive approach that prioritises public health over commercial interests, particularly when it comes to protecting our most vulnerable populations. The costs of failing to do so, measured in rising youth use rates and mental health impacts, are simply too high to ignore. (Source WRD News)
World Federation Against Drugs (W.F.A.D) Dalgarno Institute is a member of this global initiative. For evidence based data on best practice drug policy in the global context.
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Drug Free Australia Website. Drug Free Australia is a peak body, representing organizations and individuals who value the health and wellbeing of our nation...
(I.T.F.S.D.P) This international peak body continues to monitor and influence illicit drug policy on the international stage. Dalgarno Institute is a member organisation.
The National Alliance for Action on Alcohol is a national coalition of health and community organisations from across Australia that has been formed with the goal of reducing alcohol-related harm.
RiverMend Health is a premier provider of scientifically driven, specialty behavioral health services to those suffering from alcohol and drug dependency, dual disorders, eating disorders, obesity and chronic pain.
The Supreme Court is considering a case involving truck driver Douglas Horn, who was terminated after a drug test revealed THC in his system, despite using a product he believed to be THC-free. Horn has taken legal action against the product’s manufacturer, Medical Marijuana Inc., under the federal Racketeer Influenced and Corrupt Organizations Act (RICO), arguing that he suffered a business injury. During oral arguments, several justices appeared inclined to allow Horn to proceed with his claim, focusing on whether he meets the RICO requirement of being injured in business or property. The outcome could redefine how consumers seek redress against misleading product claims, particularly in the burgeoning cannabis industry.
The recent amendment to Victorian driving laws, set to take effect March 1, marks a significant shift in how medicinal cannabis users who test positive for THC while driving will be treated under the law. While proponents celebrate this as a victory for medical cannabis patients, serious concerns about road safety emerge from extensive research on cannabis impairment and driving ability.
The cannabis landscape has undergone a dramatic transformation over the past four decades, one that fundamentally changes the nature of the discussion around legalisation and youth access. This isn’t merely about policy changes – it’s about the substance itself. Cannabis potency has increased exponentially, from approximately 1% THC content in the 1980s to modern strains exceeding 20% THC, with some concentrates surpassing 90% THC. This remarkable increase in potency, driven by selective breeding and advanced cultivation techniques, raises profound questions about the applicability of historical cannabis research to current policy decisions.
