The Endocannabinoid System is No Longer the Limiting Factor: Why Policy and Stigma Continue to Delay Cannabinoid-Based Medicine

The science of the endocannabinoid system has advanced dramatically, but cannabinoid-based medicine is still being held back by forces outside the laboratory. This new Clinical Therapeutics commentary argues that the biological understanding of the endocannabinoid system is no longer the main limiting factor. The larger barriers are now policy, regulation, funding, access, and stigma.

According to the authors, restrictive and fragmented rules make cannabinoid research harder to conduct, while limited access to standardized products complicates rigorous clinical trials. At the same time, stigma within medicine can discourage research, education, prescribing, and open discussion with patients.

The message is simple: the remaining evidence gaps are not purely scientific. They are also structural. If cannabinoid-based medicine is going to move forward, policy and medical culture will have to catch up with what researchers already understand about the endocannabinoid system.

“Purpose: To examine whether the persistent gap between the extensive mechanistic knowledge of the Endocannabinoid System (ECS) and the limited number of high-quality randomized clinical trials of cannabinoid-based therapies primarily reflects scientific uncertainty or, instead, structural regulatory, economic, and social barriers.

Methods: This commentary critically synthesizes historical, regulatory, and contemporary evidence on cannabinoid research, integrating data from regulatory documents, international policy reports, clinical and observational studies, systematic reviews, and qualitative investigations. Particular emphasis is placed on barriers affecting access to standardized products, conduct of randomized clinical trials, public funding, product standardization, and healthcare professionals’ perceptions.

Findings: Although the ECS has been extensively characterized for more than three decades and cannabinoids demonstrate plausible pharmacological mechanisms across multiple therapeutic areas, clinical translation remains disproportionately limited. Persistent regulatory restrictions, inherited from prohibition policies, continue to delay access to standardized research material, increase the cost and complexity of clinical trials, and shift evidence generation toward observational designs. Regulatory fragmentation further compromises product standardization and study reproducibility, whereas persistent social and professional stigma reduces research activity, medical education, prescribing confidence, and patient disclosure, perpetuating a self-reinforcing cycle between limited evidence generation and clinical distrust.

Implications: The principal obstacle to cannabinoid-based medicine is no longer the biological understanding of the ECS but the structural environment surrounding cannabinoid research. Progress toward evidence-based clinical implementation will depend on regulatory harmonization, greater public investment in randomized clinical research, standardized pharmaceutical-quality products, and educational initiatives capable of reducing stigma among healthcare professionals. Recognizing the structural rather than scientific origin of the evidence gap is essential for informing future research priorities, editorial policies, and international regulatory strategies.”

https://pubmed.ncbi.nlm.nih.gov/42728140

“The ECS is no longer the main obstacle to cannabinoid therapeutics. Stigma and regulation continue to delay clinical translation. Standardized clinical research requires international regulatory reform. Medical education is crucial for evidence-based cannabinoid therapies.”

https://www.clinicaltherapeutics.com/article/S0149-2918(26)00317-6/fulltext

Combined Cannabidiol and Δ9-Tetrahydrocannabinol Modulate Inflammation and Nociceptive Signaling in Human Dental Pulp Cells

A new study using human dental pulp cells found that combining cannabidiol (CBD) and Δ9-tetrahydrocannabinol (THC) produced stronger anti-inflammatory effects than either cannabinoid alone. The combination reduced the pro-inflammatory cytokines IL-6, IL-12, and IL-1β while increasing the anti-inflammatory cytokine IL-10.

CBD and THC together also influenced important pathways involved in pain signaling and healing. Researchers reported increased expression of the cannabinoid receptors CNR1 and CNR2, modulation of TRPV1, and enhanced cell proliferation and migration. The combination also promoted mineralized nodule formation and increased markers associated with odontogenic differentiation and new blood-vessel formation.

The researchers concluded that combined CBD and THC show promise for promoting dental pulp healing by simultaneously influencing inflammation, nociceptive signaling, tissue repair, angiogenesis, and cell migration. The findings provide new evidence that cannabinoids may have potential applications in future vital pulp therapies designed to preserve and regenerate living dental tissue.

“Introduction: Dental pulp inflammation, caused by caries, trauma, or restorative operations, produces pain and slows regeneration. Cannabidiol (CBD) and Δ9-tetrahydrocannabinol (THC), cannabinoids of Cannabis sativa, have effects on inflammation and pain relief. However, the impact of these factors on dental pulp healing is not understood. This study investigated the combined effects of CBD and THC in controlling inflammation and nociception during dental pulp repair.

Methods: Human dental pulp cells were stimulated with lipopolysaccharide (LPS) and treated with CBD (2.5 μg/mL), THC (0.6 μg/mL), and their combination. Pro-inflammatory cytokines (IL-6, IL-12 and IL-1β) and anti-inflammatory cytokine IL-10 were analysed using qPCR and ELISA, while anti-nociceptive markers (CNR1, CNR2, and TRPV1) were evaluated by qPCR and Western blot. Cell viability, proliferation, and migration assays were performed to evaluate treatment effects on cellular behaviours associated with pulpal repair and regenerative potential.

Results: Compared with either treatment alone, the CBD/THC combination more effectively attenuated pro-inflammatory cytokines IL-6, IL-12, and IL-1β, enhanced CNR1 and CNR2 expression, modulated TRPV1, and increased IL-10 expression. Viability assays determined optimal non-cytotoxic concentrations for treatment. The combination enhanced cell proliferation and migration, promoted mineralized nodule formation, and significantly upregulated markers associated with tissue repair, odontogenic differentiation (DMP1), and angiogenesis (VEGF and bFGF).

Conclusion: Combined CBD and THC show promise for promoting dental pulp healing by modulating inflammation and nociceptive signaling, while supporting odontogenic differentiation, angiogenesis, and cell migration in human dental pulp cells. These findings provide in vitro evidence supporting combined cannabinoid treatment as a therapeutic strategy for vital pulp therapies.”

https://pubmed.ncbi.nlm.nih.gov/42722230

https://www.jendodon.com/article/S0099-2399(26)00500-5/abstract

Phytocannabinoids and bone health

A 2026 review published in Current Osteoporosis Reports examines growing evidence that phytocannabinoids may support bone health by influencing bone remodeling, inflammation, fracture healing, and bone loss.

The review highlights the endocannabinoid system as an important regulator of bone metabolism. Research involving CBD and THC shows that cannabinoids can affect osteoblasts, which build bone, and osteoclasts, which break bone down.

The review also discusses early human research showing that medical cannabis products containing THC and CBD reduced a blood marker associated with bone resorption. Together, the findings point to cannabinoids and the endocannabinoid system as promising areas for further bone-health research.

“Purpose of the review: Phytocannabinoids have received attention for their therapeutic properties, however, it is unclear how they affect bone homeostasis. Additionally, increased use of cannabis and hemp-derived products have raised questions about their impact on musculoskeletal health. This review summarizes recent studies that investigate the impact of phytocannabinoids on bone.

Recent findings: The most well studied phytocannabinoid in relation to bone health is cannabidiol (CBD). In vitro data suggests CBD inhibits osteoclasts and promotes osteoblast activity. Rodent studies have demonstrated CBD may be useful for managing bone loss associated with osteoporosis and periodontitis, as well as reducing fracture pain and promoting healing. Recent studies suggest other phytocannabinoid isolates and extracts containing multiple phytocannabinoids have varying effects on bone. The first clinical study in this area reported that a medical cannabis product reduced markers of bone turnover in healthy adults. Cannabinoids bind to receptors in the endocannabinoid system which is involved in regulation of bone metabolism. Phytocannabinoids may improve bone health; however, additional work is required to determine factors such as the optimal dose, timing, and route of administration.”

https://pubmed.ncbi.nlm.nih.gov/42709344

“Due to their diverse pharmacological properties, phytocannabinoids may have therapeutic value for bone-related disorders.”

 https://link.springer.com/article/10.1007/s11914-026-00982-1

Cannabis Medicine 2.0: Nanotechnology-Based Delivery Systems for Synthetic and Chemically Modified Cannabinoids for Enhanced Therapeutic Performance

Cannabinoid medicine is increasingly moving beyond conventional oils, capsules and extracts toward advanced drug-delivery technologies designed to improve how these compounds reach their targets in the body. This 2025 review examines how nanotechnology-based delivery systems may improve the solubility, stability, bioavailability and targeted delivery of synthetic and chemically modified cannabinoids.

Researchers reviewed nanoparticles, lipid-based carriers, micelles, nanoemulsions and other nanoengineered systems being developed for cannabinoid-related therapies. These technologies have been investigated in preclinical research involving conditions including neuropathic pain, depression and cancer, with some formulations producing longer-lasting or more targeted effects while reducing systemic exposure.

The authors conclude that combining cannabinoid pharmacology with nanotechnology could help create a new generation of more precise cannabinoid medicines, although most of these approaches remain in the preclinical stage and will require additional testing and regulatory development before widespread clinical use.

“The therapeutic potential of cannabinoids and other ligands of cannabinoid receptors attracts considerable attention due to their diverse pharmacological effects and utility in various medical applications. However, challenges such as low solubility, limited bioavailability, and potential side effects hinder their broad clinical use. Nanoformulation techniques offer a promising approach to address these issues and optimize the therapeutic effectiveness of cannabinoids and other cannabinoid receptor ligands.

This comprehensive review explores the advancements in nanoformulation strategies to enhance the therapeutic efficacy and safety of synthetic cannabinoids and related compounds, such as CB13, rimonabant, and HU-211, which have been studied in a range of preclinical models addressing conditions such as neuropathic pain, depression, and cancer.

The review discusses various nanocarriers employed in this field, including lipid-based, polymeric, and hybrid nanoparticles, micelles, emulsions, and other nanoengineered carriers. In addition to formulation approaches, this review provides an in-depth analysis of chemical structures and their effect on compound activity, especially in the context of the affinity for the cannabinoid type 1 receptor in the brain, which is chiefly responsible for the psychoactive effects.

The provided summary of research concerning either chemical modifications of existing cannabinoids or the creation of new compounds that interact with cannabinoid receptors, followed by the development of nanoformulations for these agents, allows for the identification of new research directions and future perspectives for Cannabis-based medicine.

In conclusion, the combination of nanotechnology and cannabinoid pharmacology holds promise for delivering more effective and safer therapeutic solutions for a broad spectrum of medical conditions, making this an exciting area of research with profound implications for the healthcare and pharmaceutical industries.”

“Nanotechnology-enabled delivery of synthetic and chemically modified cannabinoids offers a promising approach to overcome the intrinsic limitations of these compounds, positioning them as candidates for future precision therapeutics. Preclinical evidence supports their enhanced stability, bioavailability, and site-specific activity; however, translating these findings into clinical applications will require coordinated advances in innovation, manufacturing, and regulatory science. Nanoformulated cannabinoids have the potential to transform therapeutic strategies, but their clinical impact will depend on harmonized regulations, standardized testing, and robust translational research. With sustained international collaboration, these next-generation formulations may become a key component of personalized medicine in the coming decade.”

https://pmc.ncbi.nlm.nih.gov/articles/PMC12388155/

Nanotechnology for the Efficacious Delivery of Medicinal Cannabis and Pharmaceutical Medicines

Nanotechnology is creating new possibilities for the delivery of medicinal cannabis and pharmaceutical medicines. This 2025 narrative review examines how nanoscale delivery systems may help overcome common problems such as poor solubility, inconsistent absorption, low bioavailability, gastrointestinal degradation, and first-pass metabolism.

These challenges are especially relevant to cannabinoids such as THC and CBD because they are highly lipophilic compounds. The review discusses how nanoparticle systems may improve cannabinoid stability, targeting, controlled release, selectivity, and overall delivery while exploring alternative routes including oro-buccal, nasal, ocular, and transdermal administration.

The paper directly discusses THC, CBD, dronabinol, nabilone, nabiximols, high-THC cannabis, and NanoCelle™ formulations designed to deliver THC and CBD through the oral mucosa. The authors emphasize that nanotechnology may allow cannabinoid medicines to be delivered more precisely, with improved absorption and reduced loss through first-pass metabolism.

“The application of nanoparticles as nanomedicines, particularly for the targeted and efficacious delivery of drugs is an expanding platform in the field of cannabinoid and pharmaceutical drug delivery. By refocusing the route of drug administration beyond the oral gut pathway, this technology provides significant advancements that are especially relevant for cancer treatments. Orally administered drugs face significant challenges as they traverse the gastrointestinal tract (GIT) and are subject to first-pass GIT metabolism. Physiological conditions encountered in the GIT such as food effects, hormones, gastric pH, emptying time, and intestinal transit time vary widely across individuals. Fluid composition and enzymatic activity in the small intestine and large bowel also influence drug dissolution and absorption. These factors in conjunction with the intestinal cohort of bacteria can metabolize drugs before absorption, contributing to poor and variable drug bioavailability, which can be exacerbated by gut dysbiosis. Drug delivery that bypasses the oral-GIT route and hence first-pass metabolism offers a plausible solution for enhanced safety and drug efficacy.”

https://pmc.ncbi.nlm.nih.gov/articles/PMC12472836

Exploring the Potential of Cannabinoid Nanodelivery Systems for CNS Disorders

Cannabinoids such as THC and CBD have shown therapeutic potential in neurological disorders, but poor water solubility and low bioavailability can limit their effectiveness. This review explores how nanotechnology may overcome these barriers by improving cannabinoid stability, controlled release and targeted delivery to the central nervous system, including strategies designed to enhance passage across the blood-brain barrier.

“Cannabinoids have a major therapeutic value in a variety of disorders. The concepts of cannabinoids are difficult to develop, but they can be used and are advantageous for a number of diseases that are not sufficiently managed by existing treatments. Nanoconjugation and encapsulation techniques have been shown to be effective in improving the delivery and the therapeutic effectiveness of drugs that are poorly soluble in water. Because the bioavailability of cannabinoids is low, the challenge is to explore different administration methods to improve their effectiveness. Because cannabinoids cross the blood-brain-barrier (BBB), they modify the negative effects of inflammatory processes on the BBB and may be a key factor in the improvement of BBB function after ischemic disease or other conditions. This review discusses various types of cannabinoid administration, as well as nanotechnologies used to improve the bioavailability of these compounds in CNS diseases.”

“The growing acceptance of Cannabis and cannabinoids has led to an increasing number of clinical trials testing various nanoproducts. CNS disorders are key therapeutic targets for cannabinoids, and nanoformulation platforms for cannabinoid nanoconjugates provide efficient transport across the BBB. Selected examples of cannabinoid nanoconjugates have shown enhanced bioavailability and improved bio-efficacy with promising outcomes in biomedical applications. We expect to see many results from clinical trials in the near future to evaluate the adverse effects and effectiveness of this treatment. However, precise delivery of these nanoformulations to pathological sites inside the brain remains a challenge.”

https://pmc.ncbi.nlm.nih.gov/articles/PMC9863859/

Cannabinoids and Neurogenesis: The Promised Solution for Neurodegeneration?

molecules-logo“The concept of neurons as irreplaceable cells does not hold true today. Experiments and evidence of neurogenesis, also, in the adult brain give hope that some compounds or drugs can enhance this process, helping to reverse the outcomes of diseases or traumas that once were thought to be everlasting.

Cannabinoids, both from natural and artificial origins, already proved to have several beneficial effects (e.g., anti-inflammatory, anti-oxidants and analgesic action), but also capacity to increase neuronal population, by replacing the cells that were lost and/or regenerate a damaged nerve cell.

Neurogenesis is a process which is not highly represented in literature as neuroprotection, though it is as important as prevention of nervous system damage, because it can represent a possible solution when neuronal death is already present, such as in neurodegenerative diseases.

The aim of this review is to resume the experimental evidence of phyto- and synthetic cannabinoids effects on neurogenesis, both in vitro and in vivo, in order to elucidate if they possess also neurogenetic and neurorepairing properties.”

https://pubmed.ncbi.nlm.nih.gov/34684894/

“The current results of cannabinoids effects on neurogenesis are encouraging, and it is expectable that the amount of evidence continues to increase in the future with other experiments.”

https://www.mdpi.com/1420-3049/26/20/6313/htm

Activity of THC, CBD, and CBN on Human ACE2 and SARS-CoV1/2 Main Protease to Understand Antiviral Defense Mechanism

“THC, CBD, and CBN were reported as promising candidates against SARS-CoV2 infection, but the mechanism of action of these three cannabinoids is not understood.

This study aims to determine the mechanism of action of THC, CBD, and CBN by selecting two essential targets that directly affect the coronavirus infections as viral main proteases and human angiotensin-converting enzyme2.

Tested THC and CBD presented a dual-action action against both selected targets. Only CBD acted as a potent viral main protease inhibitor at the IC50 value of 1.86 ± 0.04 µM and exhibited only moderate activity against human angiotensin-converting enzyme2 at the IC50 value of 14.65 ± 0.47 µM.

THC acted as a moderate inhibitor against both viral main protease and human angiotensin-converting enzymes2 at the IC50 value of 16.23 ± 1.71 µM and 11.47 ± 3.60 µM, respectively.

Here, we discuss cannabinoid-associated antiviral activity mechanisms based on in silico docking studies and in vitro receptor binding studies.”

https://pubmed.ncbi.nlm.nih.gov/34638139/

https://www.thieme-connect.de/products/ejournals/abstract/10.1055/a-1581-3707

Cannabidiol inhibits SARS-Cov-2 spike (S) protein-induced cytotoxicity and inflammation through a PPARγ-dependent TLR4/NLRP3/Caspase-1 signaling suppression in Caco-2 cell line

Phytotherapy Research“Given the abundancy of angiotensin converting enzyme 2 (ACE-2) receptors density, beyond the lung, the intestine is considered as an alternative site of infection and replication for severe acute respiratory syndrome by coronavirus type 2 (SARS-CoV-2).

Cannabidiol (CBD) has recently been proposed in the management of coronavirus disease 2019 (COVID-19) respiratory symptoms because of its anti-inflammatory and immunomodulatory activity exerted in the lung.

In this study, we demonstrated the in vitro PPAR-γ-dependent efficacy of CBD (10-9 -10-7 M) in preventing epithelial damage and hyperinflammatory response triggered by SARS-CoV-2 spike protein (SP) in a Caco-2 cells. Immunoblot analysis revealed that CBD was able to reduce all the analyzed proinflammatory markers triggered by SP incubation, such as tool-like receptor 4 (TLR-4), ACE-2, family members of Ras homologues A-GTPase (RhoA-GTPase), inflammasome complex (NLRP3), and Caspase-1.

CBD caused a parallel inhibition of interleukin 1 beta (IL-1β), IL-6, tumor necrosis factor alpha (TNF-α), and IL-18 by enzyme-linked immunosorbent assay (ELISA) assay. By immunofluorescence analysis, we observed increased expression of tight-junction proteins and restoration of transepithelial electrical resistance (TEER) following CBD treatment, as well as the rescue of fluorescein isothiocyanate (FITC)-dextran permeability induced by SP.

Our data indicate, in conclusion, that CBD is a powerful inhibitor of SP protein enterotoxicity in vitro.”

https://pubmed.ncbi.nlm.nih.gov/34643000/

https://onlinelibrary.wiley.com/doi/10.1002/ptr.7302

Lung cancer patient who had declined conventional cancer treatment: could the self-administration of ‘CBD oil’ be contributing to the observed tumour regression?

b-on, bliblioteca do conhecimento online | BMJ“Conventional lung cancer treatments include surgery, chemotherapy and radiotherapy; however, these treatments are often poorly tolerated by patients. Cannabinoids have been studied for use as a primary cancer treatment. Cannabinoids, which are chemically similar to our own body’s endocannabinoids, can interact with signalling pathways to control the fate of cells, including cancer cells. We present a patient who declined conventional lung cancer treatment. Without the knowledge of her clinicians, she chose to self-administer ‘cannabidiol (CBD) oil’ orally 2-3 times daily. Serial imaging shows that her cancer reduced in size progressively from 41 mm to 10 mm over a period of 2.5 years. Previous studies have failed to agree on the usefulness of cannabinoids as a cancer treatment. This case appears to demonstrate a possible benefit of ‘CBD oil’ intake that may have resulted in the observed tumour regression. The use of cannabinoids as a potential cancer treatment justifies further research.”

https://pubmed.ncbi.nlm.nih.gov/34649854/

“Patient’s perspective

“I was not very interested in traditional cancer treatments as I was worried about the risks of surgery, and I saw my late husband suffer through the side effects of radiotherapy. My relative suggested that I should try ‘cannabidiol (CBD) oil’ to treat my cancer, and I have been taking it regularly ever since. I am ‘over the moon’ with my cancer shrinking, which I believe was caused by the ‘CBD oil’. I am tolerating it very well and I intend to take this treatment indefinitely.””

https://casereports.bmj.com/content/14/10/e244195

“Cannabis oil led to lung cancer regression in 80-year-old woman: Report”

https://www.freepressjournal.in/world/cannabis-oil-led-to-lung-cancer-regression-in-80-year-old-woman-report

“Case Report: Lung Cancer Shrinks in Patient Using CBD Oil”

https://www.medscape.com/viewarticle/960949

“Daily use of cannabidiol (‘CBD’) oil may be linked to lung cancer regression”

https://www.bmj.com/company/newsroom/daily-use-of-cannabidiol-cbd-oil-may-be-linked-to-lung-cancer-regression/
https://www.bmj.com/company/newsroom/daily-use-of-cannabidiol-cbd-oil-may-be-linked-to-lung-cancer-regression/