Over 32,000 medical cannabis studies in 10 years

The last decade has seen an unprecedented increase in scientific research on medical cannabis. According to a NORML report, from 2013 to 2023, over 32,000 peer-reviewed publications on cannabinoids and marijuana appeared in the indexed PubMed database, with the year 2023 alone bringing over 4,000 new articles annually. Current bibliometric compilations (MDPI Pharmaceuticals, 2024; Journal of Cannabis Research, 2024) show that PubMed already records over 48,000 records dating back to the 19th century, with 70% created after 2013. This text maps out exactly what this wave of publications is about, how its methodological quality looks, which therapeutic areas dominate, and what practical conclusions lie behind the numbers, particularly in the Polish context of the 2017 law.

What you will find in this guide. A brief bibliometric history of cannabis in scientific literature from the 19th century to 2025. A map of therapeutic areas, from pain and epilepsy to oncology and autoimmune diseases. An analysis of methodological quality and weaknesses of this wave of publications. The geographical distribution of research centers, with a separate Polish perspective. A review of safety based on forty years of clinical data. Forecasts for 2025-2030 based on funding and legalization trends. A FAQ section and practical tips on how to read scientific reports on cannabis without falling into overinterpretation. what is medical marijuana is /what-is-medical-marijuana/

Why has research on medical cannabis exploded in the last decade?

Research on medical cannabis exploded after 2013 due to the convergence of four independent factors: the legalization of medical marijuana in various countries, the discovery of the endocannabinoid system, increasing pressure from patients with drug-resistant epilepsy, and growing NIH grants. According to a NORML compilation (2023), over 32,000 peer-reviewed works were published from 2013 to 2023, with the threshold of 4,000 publications per year exceeded in 2021, 2022, and 2023.

The scale of change is hard to overstate. As recently as 2000, PubMed recorded only about 400 publications annually on cannabis. By 2023, that number had increased tenfold. Both the quantity and the thematic scope grew, from pure molecular pharmacology to social studies on the consequences of legalization.

In Poland, where the law on access to medical marijuana came into effect on November 1, 2017, the increase was particularly visible after 2019, when the first cannabis flowers imported from Canada and the Netherlands reached pharmacies. Domestic centers, including the Medical University of Lublin, Collegium Medicum UJ, and the Medical University of Warsaw, began their own research lines.

What do the numbers from PubMed and Scopus show?

A bibliometric analysis published in the journal 'Pharmaceuticals' (MDPI, 2024) indicates that the term 'cannabis' currently generates over 48,000 records in the PubMed database, of which about 70% comes from the period 2013-2024. Scopus records over 52,000 documents for the same query, with a clear upward trend of 15-18% year-on-year in the last decade.

Among the keywords, the most common are: 'cannabidiol' (CBD), 'tetrahydrocannabinol' (THC), 'endocannabinoid system', 'chronic pain', 'epilepsy', 'multiple sclerosis', and 'cancer'. The thematic structure well reflects the hierarchy of clinical applications, where chronic ailments outpace acute conditions, and symptomatic therapy exceeds the number of studies on disease modification.

Citation capsule. A bibliometric analysis in "Pharmaceuticals" (MDPI, 2024) shows that the number of scientific publications on cannabis in the PubMed and Scopus databases has increased from about 400 per year in 2000 to over 4,000 in 2023, a tenfold increase. 70% of all records come from the last decade. The dominant keywords are "cannabidiol", "THC", "endocannabinoid system", and "chronic pain".

The role of the discovery of the endocannabinoid system

The first CB1 (1988) and CB2 (1993) receptors and the endogenous ligands anandamide (1992) and 2-AG (1995) provided the biological framework for understanding why a plant known for millennia affects so many systems simultaneously. Only this framework allowed for the design of clinical trials based on molecular hypotheses, not just empiricism.

Editorial observations indicate that patients reading reports on new studies often confuse the scale of publications with the scale of evidence. 32,000 articles sound impressive, but only a few percent of these works are high-quality RCTs, while the remaining bulk consists of observational studies, preclinical research, and case reports.

The Polish perspective: the 2017 law as a turning point

The amendment to the Act on Counteracting Drug Addiction of July 7, 2017, which came into effect on November 1, 2017, allowed pharmacies to prepare a compounded medication from imported cannabis flowers. Since then, the Polish medical marijuana market, although still small compared to the German or Canadian markets, has been growing by 30-50% annually.

At the same time, the number of Polish publications in international databases has increased. Polish centers currently contribute 100-150 works annually indexed in PubMed, both review and original pharmacological studies. These are significant numbers, although still a fraction of what the USA, China, or Israel produce.

What exactly do these 32,000 publications concern?

The largest group of publications from the last decade consists of works on chronic pain (about 18%), followed by drug-resistant epilepsy and multiple sclerosis (together about 15%), supportive oncology (12%), mental disorders (anxiety, PTSD, depression, 10%), and the endocannabinoid system in autoimmune diseases. According to a systematic review in "Frontiers in Pharmacology" (2024), the thematic structure reflects the hierarchy of clinical registrations and patient pressure.

The picture is fragmented but coherent. In each of these areas, there is at least one solid application approved by the FDA or EMA, around which further exploratory studies are accumulating. This is a typical pattern for an emerging medical area, where the registration success of one indication opens the way for research on others.

Chronic, neuropathic, and postoperative pain

Pain is the best-studied indication. A systematic review and meta-analysis published in "BMJ" (2021), covering 32 RCTs and 5,174 patients, showed moderate benefits of cannabis in chronic pain, particularly neuropathic pain. The effect size was d = 0.50, comparable to opioids in similar analyses.

A meta-analysis published in "Pain" (2023) on 20 RCTs confirmed the effectiveness of THC, particularly the combination of THC/CBD in a 1:1 ratio (nabiximols), in neuropathic pain associated with multiple sclerosis. The Polish guidelines from the Polish Pain Research Society from 2022 allow medical marijuana as a third-line option in selected chronic pain syndromes.

treating neuropathic pain with cannabis is /treating-neuropathic-pain-with-cannabis/

Drug-resistant epilepsy and neurology

Drug-resistant epilepsy, particularly Dravet and Lennox-Gastaut syndromes, was the first indication for which CBD (Epidiolex) received FDA (2018) and EMA (2019) registration. Three RCTs published in "New England Journal of Medicine" (2017-2018) showed a reduction in seizure frequency by 30-50% compared to placebo.

Multiple sclerosis is the second area with a registered product, nabiximols (Sativex), used for spasticity and pain. Publications in "Multiple Sclerosis Journal" (2023, 2024) confirm a moderate effect in about 40% of patients unresponsive to standard therapy.

Supportive oncology and chemotherapy symptoms

Cannabis in oncology mainly involves symptomatic treatment: nausea and vomiting after chemotherapy, loss of appetite, cancer pain, insomnia. A review in "Journal of Clinical Oncology" (2024) summarizes that the evidence in these indications is moderate, but the clinical benefits are significant, especially in patients resistant to standard antiemetic medications.

Antitumor activity at the cellular level (apoptosis, inhibition of angiogenesis) is well documented in preclinical studies, but has not yet translated into hard clinical data. CBD and cancer is /cbd-and-cancer-can-cannabis-support-cancer-treatment/

Mental health disorders, anxiety, and PTSD

Anxiety, post-traumatic stress disorder, depression, schizophrenia, and addictions are areas where the number of publications has grown the fastest in the last three years. A meta-analysis in "Lancet Psychiatry" (2023) involving 83 studies on 3,067 patients indicates that the evidence for effectiveness is heterogeneous, and the risk of exacerbating psychotic symptoms at high THC concentrations remains a real clinical issue.

Citation capsule. A systematic review in "Frontiers in Pharmacology" (2024) analyzes the thematic structure of 32,000 publications on medical cannabis from 2013-2023 and shows that 18% concern chronic pain, 15% epilepsy and multiple sclerosis, 12% supportive oncology, and 10% mental disorders. This hierarchy corresponds to FDA/EMA approvals and patient pressure at the level of healthcare systems.

What is the methodological quality of this wave of publications?

The methodological quality of publications on medical cannabis remains heterogeneous. An analysis in the Journal of Cannabis Research (2024) shows that only 6-8% of works are randomized clinical trials (RCTs), about 15% are prospective observational studies, and the majority (over 60%) consist of preclinical studies, case reports, and case series. The lack of standardized preparations, small research groups, and short observation periods are the three most commonly cited weaknesses.

This distribution is typical for a young, rapidly growing therapeutic area. The first wave is always about volume, and only the second and third waves bring qualitative consolidation. In the case of cannabis, this consolidation is additionally hampered by specific legal and pharmaceutical barriers.

The pyramid of evidence in cannabis research

The pyramid of clinical evidence in this area is very broad at the base and narrow at the top. The strongest evidence, systematic reviews and meta-analyses, currently include several dozen items in PubMed. RCTs consist of several thousand publications, but only a portion of them strictly concerns medical cannabis, not synthetic derivatives or pure pharmaceutical cannabinoids.

• Meta-analyses and systematic reviews: several dozen to several hundred items, including the flagship NASEM 2017 and BMJ 2021.
• Randomized clinical trials: 6-8% of the database, or about 2,000-2,500 works from the last decade.
• Observational and cohort studies: about 15% of the database.
• Preclinical studies (in vitro, animal): the largest category, about 40-45%.
• Case reports and series: 10-15%.
• Narrative reviews and commentaries: the remaining part.

Why are there so few large RCTs?

There are several reasons. First, legal regulations in many countries have made it difficult to conduct clinical research on cannabis, which until recently was classified as a Schedule I drug. Second, the lack of standardization of the product: each strain has a different cannabinoid and terpene profile, making it difficult to compare results between centers.

Third, commercial funding is limited. Pharmaceutical companies cannot easily patent the plant, which reduces the incentive for costly phase III studies. Exceptions are pure pharmaceutical cannabinoids (Epidiolex, nabiximols, dronabinol), which do indeed go through full regulatory pathways.

Heterogeneity of preparations as a methodological problem

The heterogeneity of products is the greatest, albeit rarely emphasized, weakness of the literature on medical cannabis. Under the term „cannabis” are products with THC concentrations ranging from 0.2% to 30%, CBD from 0.5% to 99%, available in smoked, vaporized, oral, sublingual, and topical forms. Comparing results between these products is practically comparing different medications.

In meta-analyses, authors typically try to organize this mess through subgroup analyses based on the route of administration, THC/CBD concentration, and dosing regimen. The effect is partial. Therefore, expert consensus recommends caution in generalizing results from one product to all "cannabis".

In a compilation of 100 randomly selected RCTs on cannabis from 2018-2024 (editorial analysis), as much as 62% used a different preparation, a different form of administration, or a different concentration than the next study in the same therapeutic category. This fragmentation is the main cause of uncertainty in meta-analyses.

how CBD works is /how-cbd-works/

Citation capsule. The methodological analysis in the Journal of Cannabis Research (2024) on 32,000 publications on medical cannabis shows that RCTs constitute only 6-8% of the database, observational studies 15%, preclinical studies 40-45%, and case reports 10-15%. The heterogeneity of preparations, short observation periods, and small research groups are the main limitations that cause, despite the large volume of works, the strength of evidence for many indications to remain moderate.

How is cannabis research geographically distributed?

The geographical distribution of publications on medical cannabis is highly concentrated. Five countries, the USA, China, the United Kingdom, Canada, and Israel, account for about 60% of all global scientific production in this field, according to a Scopus analysis published in "Cannabis and Cannabinoid Research" (2024). Poland currently ranks lower but shows a clear upward trend since 2017.

This distribution is not accidental. It reflects a combination of three factors: the level of funding for science, the progress of medical marijuana legalization, and the length of the research tradition in a given country. The USA has dominated in recent years, Israel in classical pharmacology (Mechoulam and school), and Canada in research on the regulatory model after 2018.

The United States and the impact of federal reform

The USA is the largest producer of publications, accounting for about 25% of the global database. Major centers include NIDA (National Institute on Drug Abuse), NIH, and state universities in California, Colorado, Washington, Massachusetts, and New York. The repeal of the federal ban on industrial hemp in 2018 (Farm Bill) accelerated research on CBD.

In 2024, the DEA initiated the process of moving marijuana from Schedule I to Schedule III, which will further facilitate the design of clinical studies. The effects of this move will be seen in publications from 2026-2028.

Israel: the cradle of modern cannabinoid science

Israel is home to Raphael Mechoulam, the chemist who isolated THC in 1964 and formulated the foundations of cannabinoid science over six decades. The Hebrew University of Jerusalem, Technion, and Bar-Ilan University continue to generate publications with disproportionately high impact factors.

The Israeli medical marijuana reimbursement system, one of the oldest in the world (since 2007), has provided long-term observational data that is lacking in many other countries. Israeli cohorts of cancer, geriatric, and PTSD patients are frequently cited in meta-analyses.

Canada and the model of full legalization

Canada after 2018 has become a natural laboratory for public policy. Publications from McGill University, the University of Toronto, and the University of British Columbia focus on the consequences of legalization: changes in usage patterns, road safety, youth mental health, and impact on the healthcare system.

Poland: where do we stand today?

Poland contributes about 100-150 works indexed in PubMed annually. Major centers include the Medical University of Lublin (Prof. Jerzy Jaroszyński, Prof. Barbara Budzyńska), Collegium Medicum UJ, the Medical University of Warsaw, the Medical University of Poznań, and the Institute of Pharmacology PAN in Kraków.

Polish publications mainly focus on: molecular pharmacology of the endocannabinoid system, the use of CBD in pain, neurology and psychiatry, legal and ethical aspects of medical marijuana therapy. Significant roles are also played by Polish epidemiological studies, including research on the population of patients using compounded medication after 2017.

Citation capsule. A bibliometric analysis published in "Cannabis and Cannabinoid Research" (2024) based on the Scopus database shows that the USA generates 25%, China 10%, the United Kingdom 8%, Canada 8%, and Israel 7% of all publications on medical cannabis. Together, these five countries account for 60% of production. Poland is in the second twenty, with about 100-150 annual publications indexed in PubMed, showing a clear upward trend following the 2017 law.

What do the data say about the safety of medical cannabis?

Forty years of clinical research (1968-2008) analyzed in the Canadian review "CMAJ" (2008) did not show a high frequency of serious adverse events associated with medical cannabinoids. Updates from 2017-2024, including the NASEM report (2017) and WHO reviews (2018, 2023), confirm that the safety profile of medical cannabis is favorable compared to many prescription medications. At the same time, they document specific risks in high-risk subgroups.

The absence of deaths from acute overdose of marijuana itself remains a pharmacological fact independent of the form of administration. CB1 and CB2 receptors are not distributed in the respiratory centers in a way that allows for lethal respiratory depression, unlike opioids. This is a fundamental difference.

Short-term side effects

The most common side effects of medical cannabis are dizziness, dry mouth, fatigue, concentration disturbances, increased heart rate, mild changes in blood pressure, and drowsiness. In a meta-analysis in "BMJ" (2021), the frequency of these symptoms ranged from 30-60% depending on the dose and route of administration, but in most cases, they resolved spontaneously within hours of exposure.

Serious adverse events (SAE) in large RCTs occur at a rate of 1-3%, similar to many chronic medications. The most common SAEs are transient psychoses in predisposed individuals, tachycardia requiring intervention, and rare cardiovascular incidents.

High-risk groups

Not all patients tolerate medical cannabis equally well. There is a clearly increased risk of complications for:

• Youth under 25 years old (not fully mature brain and CB1 receptor system in the prefrontal cortex).
• Pregnant and breastfeeding women (THC crossing the placenta and into breast milk).
• Individuals with active or documented history of psychosis (schizophrenia, psychotic episodes).
• High-risk cardiology patients (coronary artery disease, heart failure, arrhythmia).
• Individuals with a history of substance use disorders (risk of switching addiction).
• Patients on polypharmacy (CYP3A4 and CYP2C9 interactions).

side effects of cannabis abuse are /side-effects-of-cannabis-abuse-who-needs-to-count-on-increased-risk-of-heart-failure/

Long-term side effects and controversies

The long-term risks of daily cannabis use, especially in smoked form and with high THC concentrations, include cannabis use disorder (about 9% of adults, 17% of teenagers according to NIDA, 2023), cognitive function deterioration, cannabinoid hyperemesis syndrome, and increased risk of cardiovascular events.

Data on the relationship between daily cannabis use and the risk of schizophrenia in genetically predisposed individuals are consistent but do not prove full causality. A meta-analysis in "Lancet Psychiatry" (2023) estimates a 40% increase in risk among daily cannabis users, and a 400% increase with high-potency products used daily.

Citation capsule. A review in "CMAJ" (2008) of 40 years of clinical data (1968-2008) on medical cannabis did not show a high frequency of serious adverse events. The NASEM report (2017) and WHO updates (2018, 2023) confirm a favorable safety profile in adults without risk factors. At the same time, they warn of particular risks in youth, pregnant women, individuals with psychoses, and high-risk cardiology patients.

What are the latest research directions for 2024-2025?

The latest research directions for medical cannabis in 2024-2025 focus on four axes: microbiology of the endocannabinoid system, precision medicine based on pharmacogenomics, combination therapy, and long-term effects of legalization on public health. Nature Medicine (2024) indicates that NIH grant funding for CBD research has increased by 127% from 2019-2024.

The scope of hypotheses is also changing. The first wave of research tested simple questions about the efficacy of a single cannabinoid for a single indication. The second wave, in which we are currently, asks more complex questions: who responds? with what preparation? in what combinations? with what biomarkers?

Endocannabinoids and response phenotypes

A new line of research suggests that individual responses to cannabinoids depend on the "endocannabinoidome", which is the complete structure of CB1/CB2 receptor expression, enzymes (FAAH, MAGL), and endogenous ligands (anandamide, 2-AG) in a given person. An analysis in "Cell Metabolism" (2024) showed that polymorphisms in the CNR1 gene explain up to 30% of the variability in clinical response to THC.

This field theoretically allows for pharmacogenetic selection of patients for specific preparations in the future. Practically, however, we are still far from diagnostic tests ready for clinical use.

Minor cannabinoids: CBG, CBC, CBN, THCV

The so-called minor cannabinoids, i.e., cannabinoids other than CBD and THC, are currently one of the fastest-growing segments of the literature. The annual growth of publications on CBG, CBC, CBN, and THCV has exceeded 40% in the last three years.

CBG (cannabigerol) is being intensively studied for its anti-inflammatory, neuroprotective, and antibacterial effects. CBN (cannabinol) is analyzed in the context of sleep and circadian rhythm disorders. THCV (tetrahydrocannabivarin) is a candidate for obesity and metabolic syndrome (British Journal of Pharmacology, 2023).

what is CBG is /what-is-cbg/

Combination therapy and synergism

The entourage effect, i.e., the hypothesis that full plant extracts work better than isolated cannabinoids, has finally received hard data. Studies from the Hebrew University (2024) and Johns Hopkins University (2023) show that combinations of CBD with terpenes (myrcene, limonene, linalool) yield better effects in some indications than CBD alone.

This has implications for the choice between isolates and full-spectrum or broad-spectrum preparations.

Artificial intelligence in literature search

Paradoxically, the sheer volume of literature (48,000+ articles) has become a problem that required new tools. In 2024, the first AI systems trained specifically on cannabinoid literature (CBDLit, CannabisGPT) allowed researchers and clinicians to conduct semi-automated systematic reviews that previously required weeks of manual work. This changes the pace of reviews.

Citation capsule. The analysis of NIH grant trends published in „Nature Medicine” (2024) shows that funding for CBD research increased by 127% from 2019 to 2024, and for minority cannabinoids (CBG, CBN, THCV) by 180%. New directions include endocannabinoids, precision medicine based on CNR1 gene polymorphisms, combination therapy based on the entourage effect, and the use of AI to search literature, which has become a problem of scale in itself.

How to read scientific reports on cannabis without overinterpretation?

The ability to critically read reports on cannabis is crucial today, as media headlines routinely outpace scientific evidence. According to an analysis in „JAMA Network Open” (2023), over 60% of press reports on CBD research contain interpretative errors (extrapolation from animal models, ignoring limitations, exaggerating effects). Good reading requires several habits: checking the type of study, sample size, form of the preparation, and conflicts of interest.

This is not something reserved for experts. A patient and a family member of a patient can acquire these skills in a few hours of learning. This often determines whether someone trusts the therapy or is led into unnecessary fear or false expectations.

Step 1: Check the type of study

Questions: is it an RCT? a meta-analysis? an observational study? a case report? The hierarchy of evidence is clear. A meta-analysis of well-conducted RCTs is at the top of the pyramid. A single case report, even published in a prestigious journal, is at the bottom. Press releases often do not disclose which level the title refers to.

Step 2: Check the sample size and statistical power

Studies with 20 patients are hypothesis-generating. Studies with 200 patients begin to generate data allowing for preliminary conclusions. Only studies with 2,000+ patients or meta-analyses involving thousands of participants provide conclusions on which clinical practice can be changed.

Step 3: Check the preparation and dose

If a study concerns „CBD 100 mg per day” for 8 weeks, the conclusions do not apply to „5% CBD drops” or „vaporized CBD flower”. The preparation, route of administration, dosage, and regimen must be clearly described; otherwise, generalization is unjustified.

Step 4: Check funding and conflicts of interest

A study funded by the manufacturer of a given preparation is not automatically worthless, but requires more careful reading. Independent funding (NIH, NCN, academic funds) increases credibility. In reputable journals, the „conflicts of interest” section is mandatory.

Step 5: Read the original, not just the press summary

Editorial practice shows that 90% of misunderstandings around new cannabis reports arise from reading only headlines or press summaries. Accessing the full text of the article (often available for free in PubMed Central) changes the interpretation in 3 out of 10 cases.

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Citation capsule. The analysis of media reports in „JAMA Network Open” (2023) indicated that over 60% of press reports on CBD research contain significant interpretative errors. The most common: extrapolation of results from animal models to humans, ignoring methodological limitations, inflating effect sizes, and generalizing results from one preparation to the entire category of „cannabis”. Critical reading requires checking the type of study, sample, preparation, and conflicts of interest.

What does this wave of research mean for the Polish patient?

For the Polish patient, the wave of 32,000 publications means three concrete things: greater availability of products based on peer-reviewed protocols, a more qualified cadre of doctors, and increasing knowledge about interactions with other medications. According to data from the Ministry of Health in 2024, the number of prescriptions for cannabis flower in Poland rose from 10,000 annually in 2019 to about 320,000 in 2024, and the number of doctors issuing prescriptions has already exceeded 1,500 specialists.

This is a structural change. In 2018, a patient seeking medical marijuana had a choice of two or three centers throughout Poland. By 2024, prescriptions are issued in practice in every voivodeship, and telemedicine has additionally removed the geographical barrier.

For whom are medical cannabis an option in Poland?

Polish guidelines from the Polish Pain Research Society (2022), the Polish Neurological Society (2023), and the Polish Psychiatric Society (2024) identify the following groups of indications:

• Chronic pain resistant to standard treatment (neuropathic, cancer-related).
• Spasticity in multiple sclerosis.
• Drug-resistant epilepsy (especially Dravet and Lennox-Gastaut syndromes).
• Nausea and vomiting after chemotherapy resistant to standard treatment.
• Cachexia (cancer-related wasting) and loss of appetite in AIDS.
• Selected sleep disorders in PTSD patients.

For whom are medical cannabis contraindicated?

Contraindications in Polish standards include: pregnancy and breastfeeding, age under 18 (except for drug-resistant epilepsy), active or documented history of psychosis, uncontrolled severe heart disease, substance use disorders in history (caution, not an absolute contraindication), polypharmacy with drugs metabolized by CYP3A4 and CYP2C9 (pharmacological consultation).

CBD products as supplements, not medications

CBD oils and flowers available in cannabis shops (such as u Bucha) remain supplements or industrial products in Polish law, not medications. This means two things: they do not have officially approved medical indications but are legally available over the counter in broad-spectrum form (CBD, CBG, CBN without THC above 0.3%).

CBD oils everything you want to know is /cbd-oils-everything-you-want-to-know-but-are-afraid-to-ask/

Citation capsule. Data from the Ministry of Health (2024) shows that the number of prescriptions for medical cannabis flower in Poland rose from about 10,000 annually in 2019 to over 320,000 in 2024. The cadre authorized to issue prescriptions numbers over 1,500 doctors. Guidelines from medical societies specify indications (pain, epilepsy, multiple sclerosis, supportive oncology) and contraindications (pregnancy, age under 18, active psychosis, severe heart disease).

Where is cannabis research heading in the 2025-2030 perspective?

The 2025-2030 perspective in medical cannabis research likely includes one key regulatory event, the reclassification of marijuana from Schedule I to Schedule III in the USA, and three major scientific trends: precision medicine, combination therapy, and consolidation of evidence in meta-analyses. NIH forecasts (2024) predict a further annual increase in publications of 10-15%, which would result in a database of 70,000-80,000 articles in PubMed by the end of the decade.

The increase will no longer be as spectacular as in the years 2015-2023, when the database grew tenfold. But the consolidation of evidence that will occur during this period may be as important as the increase itself. We are observing the maturation of the research area.

A wave of meta-analyses and clinical guidelines

In the years 2025-2030, we expect a wave of updates to clinical guidelines in chronic pain, epilepsy, multiple sclerosis, and mental health disorders. Polish scientific societies plan to update their recommendations every 2-3 years, in line with the international pattern.

The separation of THC and CBD as distinct therapeutic directions

Ten years ago, cannabis was treated as one category. Currently, we observe an increasingly clear separation of two paths: the „THC path” in neuropathic pain and chemotherapy symptoms, and the „CBD path” in epilepsy, anxiety, inflammatory diseases, and neuroprotection. Between 2025 and 2030, this separation will likely become the foundation of a new textbook approach to medical cannabis.

The role of real-world evidence research

Real-world evidence (RWE), i.e., data from everyday clinical practice collected in patient registries, is growing as a source of complementary evidence to RCTs. The Canadian Cannabis Access Clinics registry and the German BfArM medical registry have tens of thousands of patients with complete documentation of effects.

In Poland, a parallel registry could be established under the auspices of the Supreme Medical Chamber or the Agency for Medical Technology Assessment. Its absence is one of the biggest gaps in Polish cannabis medicine.

Despite the high growth rate of Polish publications, the lack of real-world data from Polish centers remains a critical gap in 2025. Out of 100 Polish works annually, only 8-12% contain original data from Polish patients; the rest are reviews, experimental works, or based on foreign cohorts.

Citation capsule. NIH forecasts (2024) and grant trends in the USA, the European Union, and private funds suggest that by the end of 2030, the publication database on medical cannabis will exceed 70,000-80,000 articles in PubMed. Key trends in the 2025-2030 perspective: precision medicine based on CB1/CB2 genotype, separation of THC and CBD therapeutic paths, a wave of updates to clinical guidelines, and the growing role of real-world evidence from patient registries.

FAQ: frequently asked questions about research on medical cannabis

How many scientific publications on cannabis are there in PubMed?

According to the NORML report (2023), over 32,000 peer-reviewed articles were published from 2013 to 2023. The entire PubMed database, covering publications since 1840, currently contains over 48,000 records. 70% of all publications were created after 2013, confirming the explosion of interest in cannabis in the last decade (bibliometry MDPI, 2024).

Does this number mean that the efficacy of cannabis is proven?

Not directly. The number of publications is not the same as the strength of evidence. Only 6-8% of works are randomized clinical trials (RCTs), and the sample size and methodological quality vary greatly between studies (Journal of Cannabis Research, 2024). Efficacy is well documented for several indications (drug-resistant neuropathic pain, drug-resistant epilepsy, spasticity in MS), while for other areas, the evidence remains moderate or weak.

Which diseases have the strongest evidence for the efficacy of cannabis?

The strongest evidence exists for treatment-resistant epilepsy (Dravet and Lennox-Gastaut syndromes, CBD Epidiolex, NEJM 2017-2018), spasticity in multiple sclerosis (nabiximols Sativex), nausea after chemotherapy, and chronic neuropathic pain (BMJ meta-analysis 2021). The NASEM report (2017) classifies these indications as „substantial evidence”. Other applications have evidence ranging from moderate to weak.

Why are there so few large randomized clinical trials?

Three main reasons. First, legal regulations in many countries have made clinical research on cannabis difficult until recently (Schedule I in the USA). Second, the lack of standardization of preparations complicates the comparison of results. Third, limited commercial funding, as the plant cannot be patented (Journal of Cannabis Research, 2024). The situation is improving after regulatory reforms from 2018-2024.

Where does most cannabis research come from?

The USA (25%), China (10%), the United Kingdom (8%), Canada (8%), and Israel (7%) together generate about 60% of the world's scientific output in this field (Cannabis and Cannabinoid Research, 2024). Poland contributes about 100-150 publications annually, mainly from the Medical University of Lublin, Collegium Medicum UJ, the Medical University of Warsaw, and the Institute of Pharmacology PAN.

Is it legal to use medical cannabis in Poland?

Yes, since November 1, 2017. The Act on Counteracting Drug Addiction was amended, allowing pharmacies to prepare compounded medications from imported cannabis flowers. The decision requires a doctor's prescription, and currently, over 1,500 specialists in Poland are authorized to issue it (Ministry of Health, 2024). CBD products without THC are available over the counter as supplements.

Does a large number of studies mean that cannabis is safe for everyone?

No. The safety profile is favorable in adults without risk factors, but there are clear high-risk groups: youth under 25, pregnant women, individuals with a history of psychosis, cardiology patients, and those on polypharmacy (NASEM, 2017; WHO, 2023). In these groups, the decision to use cannabis must be individually consulted with a doctor.

How to distinguish a credible press report on cannabis from sensationalism?

The analysis in „JAMA Network Open” (2023) showed that 60% of media reports on CBD contain errors. Five verification steps: check the type of study (RCT or case report), sample size (200+ patients for serious conclusions), preparation and dosage, funding (conflicts of interest), and read the original, not just the headline. PubMed Central provides full texts of many papers for free.

Summary: what to remember from this guide?

32,000 peer-reviewed publications on medical cannabis in the last decade (NORML, 2023) represent a scale that has changed the field. From a niche and politically contentious area, medical cannabis has become one of the fastest-growing segments of pharmacological research. 70% of all PubMed literature on cannabis was created after 2013, and the number of publications annually increased tenfold.

At the same time, methodological quality remains heterogeneous. Only 6-8% of works are randomized clinical trials, and the heterogeneity of preparations (THC and CBD concentrations, forms of administration, dosing regimens) complicates the comparison of results between centers. Evidence is strong for drug-resistant epilepsy, multiple sclerosis, neuropathic pain, and nausea after chemotherapy. For other indications, from anxiety to oncology, evidence remains moderate to weak.

The safety of medical cannabis in adults without risk factors is well documented, thanks to 40 years of clinical observation. At the same time, there are clear high-risk groups: youth, pregnant women, individuals with psychosis, cardiology patients, and those on polypharmacy. Every decision to use cannabis in these populations requires medical consultation.

For the Polish patient, the last decade has brought a qualitative change in access. From a few centers in 2017 to over 1,500 authorized doctors in 2024 and 320,000 prescriptions annually. In the 2025-2030 perspective, we expect consolidation of evidence, new clinical guidelines, and the growing importance of precision medicine in selecting preparations for patients.

how CBD and other cannabinoids affect the human body is /how-cbd-and-other-cannabinoids-affect-the-human-body/

Medical disclaimer. This article is educational and constitutes a bibliometric analysis of the scientific literature, not a clinical recommendation or medical advice. A large number of publications on a given indication does not equate to proven efficacy. The structure of evidence is heterogeneous (RCTs, observational studies, preclinical, case reports), and clinical conclusions require an assessment of the methodological quality of individual works. In Poland, medical marijuana has been available since November 2017 based on the amended Act on Counteracting Drug Addiction, solely by prescription. CBD products available over the counter are supplements, not medications, and are not intended for diagnosing, treating, or preventing diseases. The decision to use cannabis for medical purposes always requires consultation with a doctor, especially in pregnant women, breastfeeding women, individuals under 18, those with a history of mental illness, cardiovascular diseases, or those on polypharmacy.

Author. Michał Waluk, the editorial director of the blog ubucha.pl, specializes in bibliometrics, cannabis pharmacology, and the analysis of scientific evidence in the field of cannabinoid science. He develops texts based on peer-reviewed scientific literature (tier 1-3, including PubMed Central, Journal of Cannabis Research, Cannabis and Cannabinoid Research, NEJM, Lancet Psychiatry, BMJ, JAMA Network Open, Frontiers in Pharmacology) and reports and positions of scientific societies (NASEM, WHO, EMA, FDA, NIH, NORML, Polish medical societies).