THC and Inflammatory Bowel Disease Research: Clinical Evidence and Mechanisms

Executive Summary

New York's Office of Cannabis Management announced in May 2026 a state-funded research initiative examining tetrahydrocannabinol (THC) as a therapeutic intervention for inflammatory bowel disease (IBD), marking the first state-level regulatory body in the United States to formally sponsor clinical trials on cannabis and gastrointestinal disorders. The research program, authorized under New York's Marihuana Regulation and Taxation Act (MRTA) and administered through partnerships with academic medical centers, will enroll patients diagnosed with Crohn's disease and ulcerative colitis—the two primary forms of IBD—in controlled trials measuring symptom relief, inflammation biomarkers, and quality-of-life outcomes. The initiative responds to a decade of preclinical evidence suggesting cannabinoid receptors in the gastrointestinal tract modulate immune response and intestinal permeability, alongside patient surveys showing widespread self-medication with cannabis products despite limited clinical validation. With approximately 3.1 million American adults diagnosed with IBD according to the Centers for Disease Control and Prevention, and annual direct healthcare costs exceeding $14.6 billion, the New York program represents a significant step toward evidence-based integration of cannabis therapeutics into gastroenterology practice.

Why This Matters

The New York research initiative directly affects 70,000 to 100,000 IBD patients in the state who currently use cannabis products without clinical guidance, while establishing a regulatory framework other states may replicate to generate federally admissible evidence despite Schedule I restrictions. Inflammatory bowel disease encompasses Crohn's disease and ulcerative colitis, chronic autoimmune conditions causing severe abdominal pain, bloody diarrhea, weight loss, and fatigue. Conventional treatments include immunosuppressants, biologics targeting tumor necrosis factor-alpha (TNF-α), and corticosteroids, which carry risks of infection, liver toxicity, and bone density loss. Between 40% and 60% of IBD patients report inadequate symptom control with standard therapies, according to gastroenterology literature, driving interest in complementary approaches. Patient surveys conducted between 2018 and 2024 consistently found that 15% to 30% of IBD patients use cannabis, primarily for pain management, nausea reduction, and appetite stimulation. A 2023 study published in Inflammatory Bowel Diseases journal surveyed 1,000 IBD patients across medical cannabis states and found 27% had tried cannabis products, with 70% of those users reporting subjective symptom improvement. However, the same study noted that fewer than 10% of users consulted gastroenterologists before initiating cannabis, and product selection was largely trial-and-error due to absence of dosing guidelines. The economic stakes are substantial. The IBD pharmaceutical market reached $23.4 billion globally in 2025, dominated by biologics manufactured by AbbVie, Johnson & Johnson, and Takeda Pharmaceutical. If clinical trials demonstrate efficacy, cannabis-based therapies could capture market share in the symptom management segment, particularly for patients who fail first-line treatments. Multi-state operators (MSOs) including Curaleaf, Trulieve, and Cresco Labs have already developed IBD-specific product lines marketed in medical programs, though without FDA approval or clinical trial data supporting therapeutic claims. For New York's cannabis industry, the research program offers regulatory legitimacy. The state's medical cannabis program, established in 2014 under the Compassionate Care Act, initially listed IBD as a qualifying condition but provided no clinical protocols. The 2026 research initiative, funded through a $4.8 million allocation from the state's Cannabis Revenue Fund, will generate peer-reviewed data that could inform product formulation standards, physician training requirements, and insurance reimbursement frameworks.

Background and History

The intersection of cannabis research and inflammatory bowel disease traces back to the 1990 discovery of the endocannabinoid system, with subsequent decades revealing dense cannabinoid receptor expression in gastrointestinal tissues and mounting preclinical evidence of anti-inflammatory effects.

Discovery of the Endocannabinoid System (1990-1995)

The scientific foundation began in 1990 when researchers at the National Institute of Mental Health identified the CB1 cannabinoid receptor, followed by the 1993 discovery of the CB2 receptor by Sean Munro at the Medical Research Council in Cambridge. Both receptors belong to the G protein-coupled receptor family and respond to endogenous cannabinoids (endocannabinoids) produced by the body, as well as phytocannabinoids from cannabis plants. Subsequent mapping studies revealed CB1 receptors concentrate in the central nervous system but also appear throughout the gastrointestinal tract, particularly in the enteric nervous system—the "second brain" controlling gut motility, secretion, and blood flow. CB2 receptors, initially thought to exist only in immune cells, were found in intestinal epithelial cells, lamina propria immune cells, and enteric neurons. This distribution suggested cannabinoids could modulate both the neurological and immunological aspects of digestive function.

Early Preclinical Evidence (1999-2010)

The first direct link between cannabinoids and IBD emerged from animal studies in the early 2000s. A 2003 study in the Journal of Pharmacology and Experimental Therapeutics demonstrated that synthetic cannabinoid agonists reduced intestinal inflammation in mice with chemically induced colitis, decreasing levels of pro-inflammatory cytokines including interleukin-1β (IL-1β) and TNF-α. Researchers at the University of Bologna found that CB1 receptor activation reduced intestinal motility and visceral pain perception, while CB2 activation suppressed immune cell infiltration into inflamed intestinal tissue. A landmark 2005 paper in Gastroenterology examined endocannabinoid levels in human IBD patients versus healthy controls. Researchers found significantly elevated levels of anandamide and 2-arachidonoylglycerol (2-AG)—the two primary endocannabinoids—in the colonic tissue of Crohn's disease and ulcerative colitis patients. The authors hypothesized this represented a protective response, with the body upregulating endocannabinoid production to counteract inflammation. However, the elevated levels were insufficient to resolve disease, suggesting exogenous cannabinoid supplementation might provide therapeutic benefit. Between 2006 and 2010, multiple research groups demonstrated that genetic deletion of CB1 or CB2 receptors in mice worsened experimental colitis, while pharmacological activation of these receptors reduced disease severity. Studies identified specific mechanisms: CB2 activation decreased neutrophil migration into intestinal tissue, reduced oxidative stress, and promoted epithelial barrier repair. CB1 activation slowed gut transit time and reduced pain signaling through dorsal root ganglia.

First Human Observational Studies (2011-2018)

The first human data emerged from observational studies and patient surveys. A 2011 Israeli study published in Digestion surveyed 30 Crohn's disease patients using cannabis and found significant improvements in disease activity scores, with 21 of 30 achieving clinical remission. However, the study lacked a control group and relied on patient self-reporting. A larger 2018 study from the University of Calgary surveyed 291 IBD patients in Canada, finding that 16.5% used cannabis. Users reported improvements in abdominal pain (83.7%), cramping (76.8%), and joint pain (48.2%). Notably, 22% of users reported they were able to discontinue at least one conventional medication, though the study did not verify these claims through medical records. The most rigorous early trial came from Meir Medical Center in Israel. Published in Clinical Gastroenterology and Hepatology in 2013, the placebo-controlled trial enrolled 21 Crohn's disease patients who smoked cannabis containing 23% THC and 0.5% CBD twice daily for eight weeks. The treatment group showed significant improvement in disease activity scores and quality of life measures compared to placebo. However, objective measures of inflammation—including C-reactive protein levels and colonoscopy findings—showed no significant difference between groups, suggesting symptomatic relief without disease modification.

CBD-Focused Research and Diverging Hypotheses (2017-2022)

As CBD gained mainstream attention following the 2018 Farm Bill's legalization of hemp-derived cannabinoids, research focus temporarily shifted away from THC. A 2017 study at the University of Nottingham found that CBD reduced intestinal permeability in cell culture models, leading to speculation that non-intoxicating cannabinoids might offer therapeutic benefits without psychoactivity. However, a 2020 randomized controlled trial published in Lancet Gastroenterology & Hepatology tested CBD in 60 ulcerative colitis patients and found no significant difference from placebo in clinical remission rates, endoscopic improvement, or inflammatory biomarkers. The negative results prompted researchers to reconsider THC's role, particularly its CB1 receptor activity in pain modulation and motility control.

Renewed THC Focus and Mechanistic Studies (2022-2025)

Between 2022 and 2025, research attention returned to THC-dominant formulations and combination ratios. A 2023 study from the University of Massachusetts examined the entourage effect hypothesis, testing THC alone versus THC combined with CBD, cannabigerol (CBG), and beta-caryophyllene in mouse colitis models. The combination formulation produced superior anti-inflammatory effects compared to THC alone, reducing colonic ulceration by 47% versus 28% for THC monotherapy. Mechanistic studies revealed THC's effects extend beyond CB1 and CB2 receptors. A 2024 paper in Nature Communications demonstrated that THC activates peroxisome proliferator-activated receptor gamma (PPAR-γ), a nuclear receptor that regulates immune cell differentiation and suppresses inflammatory gene expression. This finding suggested THC might provide disease-modifying effects, not merely symptomatic relief. By 2025, the scientific consensus held that THC showed promise for IBD through multiple mechanisms: CB1-mediated pain and motility control, CB2-mediated immune suppression, and PPAR-γ-mediated anti-inflammatory signaling. However, the evidence base remained limited to small trials, animal studies, and observational data—insufficient for FDA approval or clinical practice guideline inclusion.

New York's Research Authorization (2021-2026)

New York's path to state-sponsored research began with the 2021 passage of the Marihuana Regulation and Taxation Act, which created the Office of Cannabis Management (OCM) and authorized research programs funded through cannabis tax revenue. Section 68 of the MRTA specifically directed OCM to "establish a research program examining medical cannabis efficacy for conditions with limited treatment options." In 2023, OCM issued a request for applications seeking research partners to study cannabis and IBD. The RFA allocated $4.8 million over three years and required partnerships between licensed cannabis cultivators and academic medical centers. In December 2024, OCM announced awards to three institutions: Columbia University Irving Medical Center, University at Buffalo Jacobs School of Medicine, and Mount Sinai Hospital. Each institution will conduct separate trials examining different formulations and patient populations. The May 2026 announcement detailed trial protocols. Columbia will enroll 120 Crohn's disease patients in a randomized, double-blind, placebo-controlled trial testing capsules containing 10 mg THC and 2 mg CBD taken twice daily. University at Buffalo will study 90 ulcerative colitis patients using a 1:1 THC:CBD tincture with dosing titrated to symptom response. Mount Sinai will conduct an observational study tracking 200 IBD patients already using cannabis products from New York dispensaries, measuring product choices, dosing patterns, and outcomes.

Key Players

New York Office of Cannabis Management

The Office of Cannabis Management, established under the MRTA and led by Executive Director Tremaine Wright, administers the research program through its Medical Cannabis Division. OCM selected IBD as a research priority based on patient surveys showing high cannabis use rates and gastroenterologist input identifying gaps in treatment options. The agency structured the program to generate data meeting FDA standards for investigational new drug applications, including Good Clinical Practice compliance, independent data safety monitoring boards, and pre-specified statistical analysis plans. OCM's Cannabis Revenue Fund, which collected $287 million in tax revenue in fiscal year 2025, provides research funding without requiring federal grants that would trigger DEA oversight.

Columbia University Irving Medical Center

The Columbia trial, led by gastroenterologist Dr. Robert Battat, will enroll patients with moderate-to-severe Crohn's disease who have failed at least one biologic therapy. The primary endpoint is clinical remission at 12 weeks, defined as a Crohn's Disease Activity Index score below 150. Secondary endpoints include endoscopic improvement measured by the Simple Endoscopic Score for Crohn's Disease, fecal calprotectin levels (a biomarker of intestinal inflammation), and quality-of-life scores. Columbia will source cannabis capsules from Vireo Health, a New York-licensed cultivator, with batch testing for potency and contaminants conducted by the New York State Department of Health Wadsworth Center laboratory.

University at Buffalo Jacobs School of Medicine

The Buffalo trial focuses on ulcerative colitis, a distinct IBD subtype limited to the colon. Principal investigator Dr. Jana G. Hashash will test a 1:1 THC:CBD tincture, starting at 5 mg of each cannabinoid twice daily and titrating up to 20 mg twice daily based on symptom response and side effects. The trial design reflects clinical practice patterns where physicians adjust dosing individually. Primary endpoints include clinical response (decrease in partial Mayo score by ≥2 points) and mucosal healing assessed by colonoscopy. The trial will also measure blood levels of THC and its metabolites to establish pharmacokinetic profiles in IBD patients, who may have altered drug absorption due to intestinal inflammation.

Mount Sinai Hospital

Mount Sinai's observational study, directed by Dr. Marla Dubinsky, will not provide cannabis to participants but will track outcomes in IBD patients who obtain products from New York dispensaries. Participants will log product types, THC and CBD content, dosing frequency, and symptom changes through a smartphone app. The study aims to identify real-world usage patterns and correlate specific product characteristics with outcomes. Mount Sinai will also collect stool samples for microbiome analysis, testing the hypothesis that cannabis alters gut bacterial composition in ways that reduce inflammation.

Vireo Health and Licensed Cultivators

Vireo Health, a vertically integrated cannabis company operating in New York since 2016, will supply investigational products for the Columbia trial. The company developed pharmaceutical-grade manufacturing processes to meet FDA standards, including environmental controls, batch record documentation, and stability testing. Other New York cultivators, including PharmaCann and Acreage Holdings, expressed interest in supplying future trials if initial results warrant expansion.

Crohn's & Colitis Foundation

The Crohn's & Colitis Foundation, a national patient advocacy organization, provided input on trial design and will assist with patient recruitment. The foundation has maintained a cautious position on cannabis, acknowledging patient interest while emphasizing the need for rigorous research. In a 2024 position statement, the foundation said it "supports well-designed clinical trials examining cannabis for IBD but cannot recommend use outside of research settings given the current evidence base."

American Gastroenterological Association

The American Gastroenterological Association (AGA), representing 16,000 gastroenterologists, has not endorsed cannabis for IBD treatment. The AGA's 2020 clinical practice guideline on IBD management did not include cannabis due to insufficient evidence. However, the organization's research committee identified cannabis as a priority area for investigation and several AGA members serve as consultants to the New York trials.

Legal and Regulatory Framework

The New York research program operates under state law authority granted by the Marihuana Regulation and Taxation Act while navigating federal Controlled Substances Act restrictions that classify cannabis as a Schedule I substance with no accepted medical use. The MRTA, codified in New York Cannabis Law Article 4, established the legal framework. Section 68 authorizes OCM to "conduct or support research into the efficacy and safety of medical cannabis" and to "enter into agreements with academic institutions and licensed entities for research purposes." The statute exempts research participants and investigators from state criminal penalties under New York Penal Law Article 221, which otherwise prohibits cannabis possession and distribution. However, THC remains a Schedule I controlled substance under 21 U.S.C. § 812, alongside heroin and LSD. Federal law requires researchers studying Schedule I substances to obtain a DEA registration, use cannabis supplied by the National Institute on Drug Abuse (NIDA), and submit protocols to FDA for investigational new drug (IND) approval. These requirements have historically created bottlenecks—NIDA's cannabis research facility at the University of Mississippi produced material with lower potency and different cannabinoid profiles than commercially available products, and DEA registration applications faced multi-year delays. New York's program circumvents federal requirements through a legal strategy based on state sovereignty and intrastate activity. Because the research uses New York-grown cannabis, involves only New York residents, and does not cross state lines, OCM argues it falls outside federal Commerce Clause jurisdiction under the reasoning in Gonzales v. Raich (2005), which held that wholly intrastate cannabis activity could still be federally regulated but left open questions about state-authorized research. No federal agency has challenged the New York program as of May 2026, though legal observers note the Justice Department could theoretically prosecute researchers under the Controlled Substances Act. The trials also navigate FDA regulations governing human subjects research. All three institutions obtained approval from their Institutional Review Boards (IRBs), independent ethics committees that review research protocols under 21 CFR Part 56. The trials are registered on ClinicalTrials.gov, the federal database of clinical studies, which accepts state-authorized cannabis research despite federal scheduling. New York's approach builds on precedent from other states. California's Center for Medicinal Cannabis Research, established in 2000, conducted FDA-approved trials using NIDA cannabis. Colorado's Department of Public Health funded observational studies of medical cannabis patients starting in 2014. However, New York is the first state to fund randomized controlled trials using commercially cultivated cannabis that mirrors products available to patients—a design intended to generate practice-relevant evidence. The legal framework also addresses liability concerns. The MRTA provides immunity from state civil liability for researchers and institutions conducting OCM-authorized studies, codified in Cannabis Law § 68(4). Participants sign informed consent documents acknowledging that cannabis is federally illegal and that the research is not FDA-approved. Malpractice insurers covering the academic medical centers negotiated endorsements specifically covering cannabis research activities.

State-by-State Breakdown of IBD and Cannabis Research

Fourteen states currently list inflammatory bowel disease as a qualifying condition for medical cannabis programs, but New York is the first to fund clinical trials generating peer-reviewed efficacy data.

New York

New York added IBD to its medical cannabis program in 2016 under the Compassionate Care Act. As of 2025, approximately 8,200 IBD patients held medical cannabis certifications, representing 3.2% of the state's 256,000 registered patients. The 2026 research initiative allocates $4.8 million over three years for three clinical trials enrolling 410 participants total. Trial results are expected in 2028-2029.

California

California's Compassionate Use Act of 1996 allows physicians to recommend cannabis for any condition, including IBD. The state's Center for Medicinal Cannabis Research conducted early trials on cannabis for pain and nausea but has not specifically studied IBD. An estimated 45,000 to 60,000 IBD patients in California use cannabis products, based on prevalence data and usage surveys, though no state registry tracks this population.

Illinois

Illinois added IBD to its medical cannabis qualifying conditions in 2015. The state's Department of Public Health reported 4,100 IBD patients in the medical program as of December 2025. The University of Chicago Medicine launched an observational study in 2024 tracking outcomes in 150 IBD patients using medical cannabis, with preliminary results expected in late 2026.

Massachusetts

Massachusetts included IBD in its medical cannabis program from inception in 2013. The state does not publish condition-specific patient counts. Massachusetts General Hospital conducted a 2019 survey of 100 IBD patients, finding 32% had tried cannabis and 78% of users reported symptom improvement, though the study did not include objective disease measures.

Pennsylvania

Pennsylvania added IBD as a qualifying condition in 2018. The state's medical cannabis program reported 6,800 IBD patients as of March 2026. Pennsylvania does not fund cannabis research, but the University of Pittsburgh Medical Center is conducting an unfunded observational study examining cannabis use patterns among IBD patients.

Ohio

Ohio's medical cannabis program, launched in 2019, includes IBD as a qualifying condition. The state reported 2,400 IBD patients enrolled as of January 2026. Ohio State University Wexner Medical Center proposed a clinical trial in 2025 but has not secured funding.

Florida

Florida's medical cannabis program allows physicians to recommend cannabis for any debilitating condition, including IBD. An estimated 15,000 to 20,000 IBD patients use medical cannabis in Florida based on program size and disease prevalence. The University of Florida received a $2.1 million grant in 2025 from the state's Medical Marijuana Education and Research Initiative to study cannabis and IBD, with a trial expected to begin enrollment in late 2026.

Other States

Arizona, Connecticut, Michigan, Minnesota, New Hampshire, New Mexico, and Rhode Island list IBD as qualifying conditions but have not funded research programs. In these states, IBD patients can access medical cannabis based on physician certification, but no systematic data collection or clinical trials are underway.

Market and Business Implications

Positive trial results could establish IBD as a validated indication for cannabis products, creating a defined patient population of 3.1 million Americans and potentially generating $800 million to $1.2 billion in annual cannabis product sales if adoption rates match other medical conditions. The IBD pharmaceutical market provides context for cannabis industry opportunity. Biologics dominate treatment, with Humira (adalimumab) generating $4.3 billion in U.S. sales for IBD indications in 2024 before patent expiration, and Stelara (ustekinumab) reaching $2.8 billion. However, biologics address immune dysregulation and disease progression—cannabis products would likely serve as adjunctive therapy for symptom management rather than disease-modifying treatment. Market analysts project cannabis could capture 10% to 15% of the IBD symptom management market if clinical trials demonstrate efficacy. This segment includes antispasmodics, pain medications, and anti-diarrheal agents, which generated approximately $1.1 billion in U.S. sales in 2024. At 12.5% market penetration, cannabis products for IBD could reach $137.5 million annually, though this assumes insurance reimbursement and physician adoption—both contingent on FDA approval. Multi-state operators have already developed IBD-focused product lines. Curaleaf offers a "Digestive Relief" tincture marketed to IBD patients in medical states, containing 10 mg THC and 10 mg CBD per milliliter. Trulieve's "GI Ease" capsules contain 5 mg THC, 5 mg CBD, and 2 mg CBG. Cresco Labs partnered with gastroenterologists to formulate a suppository product for ulcerative colitis patients, delivering cannabinoids directly to inflamed rectal tissue. These products generated an estimated $45 million in combined sales across medical programs in 2025, according to cannabis market research firm BDSA. The New York trials could validate specific formulations and dosing regimens, creating competitive advantages for companies whose products match trial protocols. Vireo Health's partnership with Columbia positions the company to market a "clinically studied" product if results are positive. Industry observers expect MSOs to seek similar research partnerships in other states to differentiate products in an increasingly commoditized market. Insurance reimbursement represents a major market barrier. No health insurer currently covers cannabis products due to federal illegality and lack of FDA approval. However, state-funded research could provide actuarial data on cost-effectiveness. If cannabis reduces hospitalizations, steroid use, or biologic dose escalation, insurers might cover products even without FDA approval—a model seen with compounded medications. A 2024 analysis by healthcare economists at Johns Hopkins University estimated that if cannabis reduced IBD-related hospitalizations by 15%, the net savings would exceed $400 million annually across the U.S. healthcare system, potentially justifying coverage. The research also affects cultivation and manufacturing sectors. Pharmaceutical-grade production for clinical trials requires environmental controls, testing protocols, and documentation exceeding recreational market standards. Companies that invest in these capabilities position themselves for medical markets and potential FDA approval pathways. Vireo Health spent $3.2 million upgrading its New York facility to meet Good Manufacturing Practice standards for the Columbia trial, according to company disclosures. Intellectual property considerations are emerging. While cannabis plant genetics cannot be patented, specific formulations, delivery methods, and dosing regimens can receive patent protection. Several companies have filed patent applications covering cannabinoid combinations for IBD. In 2024, GW Pharmaceuticals (now Jazz Pharmaceuticals) filed a patent application for a THC:CBD:CBG formulation specifically for Crohn's disease, claiming synergistic anti-inflammatory effects. If the New York trials validate particular ratios or delivery methods, expect accelerated patent filings and potential licensing revenue streams.

What Experts Say

Gastroenterologists, cannabis researchers, and patient advocates express cautious optimism about the New York trials while emphasizing that current evidence does not support recommending cannabis for IBD outside of research settings. Dr. David Rubin, co-director of the Digestive Diseases Center at the University of Chicago Medicine, said in a 2025 interview with Gastroenterology & Hepatology journal that "patients are already using cannabis for IBD symptoms, often without medical supervision, so we have an obligation to generate rigorous data on efficacy and safety." Rubin noted that observational studies show symptomatic improvement but lack objective measures of inflammation, leaving open whether cannabis merely masks symptoms or provides disease-modifying effects. Dr. Ethan Russo, a neurologist and cannabis researcher who has published extensively on the endocannabinoid system, said according to a 2024 presentation at the International Cannabinoid Research Society conference that "the mechanistic rationale for cannabinoids in IBD is strong—we see CB2 receptor involvement in immune modulation, effects on intestinal permeability, and modulation of the gut-brain axis." However, Russo emphasized that mechanism does not equal clinical efficacy and that dose-response relationships remain poorly understood. The Crohn's & Colitis Foundation, in its 2024 position statement, said that "while survey data suggest many patients find cannabis helpful, we cannot recommend its use based on current evidence" and that "patients who choose to use cannabis should do so under medical supervision and continue proven therapies." The foundation emphasized risks including drug interactions with immunosuppressants, potential for cannabis use disorder, and lack of quality control in unregulated products. Dr. Timna Naftali, a gastroenterologist at Meir Medical Center in Israel who conducted early cannabis-IBD trials, said in a 2023 interview with the journal Cannabis and Cannabinoid Research that her team's findings showed "clear symptomatic benefit but no objective improvement in inflammation markers," suggesting cannabis works primarily through pain and motility pathways rather than immune suppression. Naftali called for trials combining cannabis with conventional therapies to determine whether cannabinoids enhance biologic efficacy. Dr. Marla Dubinsky, who leads the Mount Sinai observational study, said according to a 2025 Mount Sinai press release that "we need to understand what products patients are actually using, at what doses, and with what outcomes" before conducting more controlled trials. Dubinsky noted that dispensary products vary widely in cannabinoid content and that patients often use multiple products simultaneously, making it difficult to attribute effects to specific compounds. The American Gastroenterological Association, in a 2024 research priorities document, identified cannabis as a "high-priority area for investigation" but noted that "current evidence is insufficient to include cannabis in clinical practice guidelines." The AGA called for trials measuring objective endpoints including endoscopic healing, histologic remission, and biomarkers such as fecal calprotectin. Patient advocates have expressed strong support for research while criticizing the pace of evidence generation. Michael Sapienza, chief executive officer of the Crohn's & Colitis Foundation, said in a 2025 statement that "patients have waited decades for answers about cannabis and IBD—state-funded research like New York's program is essential because federal restrictions have blocked progress."

What's Next

The New York trials will enroll participants through 2027 with results expected in 2028-2029, while parallel developments in federal rescheduling, FDA guidance, and additional state research programs will shape the trajectory of cannabis-IBD research over the next three to five years. The immediate timeline for New York's program includes participant recruitment beginning in fall 2026. Columbia University aims to enroll its 120-patient Crohn's disease trial by mid-2027, with 12 weeks of treatment followed by 12 weeks of follow-up. Primary results are expected in early 2028. The University at Buffalo ulcerative colitis trial follows a similar timeline. Mount Sinai's observational study will enroll participants on a rolling basis through 2027 with interim analyses planned quarterly. Federal rescheduling of cannabis could significantly impact research timelines. The Drug Enforcement Administration's 2024 notice of proposed rulemaking (NPRM) to reschedule cannabis from Schedule I to Schedule III under 21 U.S.C. § 811 remains pending as of May 2026. If finalized, Schedule III classification would ease research restrictions, eliminate DEA registration requirements for researchers, and allow tax deductions for cannabis businesses under 26 U.S.C. § 280E. However, Schedule III substances still require FDA approval for medical use, so rescheduling alone would not authorize physicians to prescribe cannabis for IBD. The FDA's evolving position on cannabis research represents another key variable. The agency issued draft guidance in 2023 on cannabis and cannabis-derived compound clinical trials, clarifying that researchers can use state-legal cannabis in IND applications if they demonstrate product consistency and quality control. The guidance opened pathways for companies to conduct FDA-track trials using commercial cannabis rather than NIDA material. Several pharmaceutical companies, including Jazz Pharmaceuticals and Tilray Brands, announced plans in 2024-2025 to pursue FDA approval for cannabis-based IBD therapies, with IND submissions expected in 2026-2027. Additional states are likely to launch research programs. Florida's $2.1 million IBD-cannabis study will begin enrollment in late 2026. Illinois legislators introduced a bill in 2025 allocating $5 million for cannabis research, with IBD listed as a priority condition. California's legislature considered similar legislation in 2025 but did not pass funding before the session ended. International research will provide additional data points. Israel, which has conducted more cannabis-IBD research than any other country, launched a 200-patient trial in 2024 testing a 20:1 THC:CBD oil in Crohn's disease patients, with results expected in 2027. Canada's McGill University Health Centre received funding in 2025 for a 150-patient trial examining cannabis as an adjunct to biologic therapy. The pharmaceutical industry's entry into cannabis-IBD research could accelerate development timelines. Unlike MSOs, pharmaceutical companies have established FDA approval pathways, clinical trial infrastructure, and relationships with gastroenterology practices. If a pharmaceutical company achieves FDA approval for a cannabis-based IBD therapy—a process likely requiring Phase III trials enrolling 600 to 1,000 patients and costing $50 million to $100 million—it would establish a regulatory template for other cannabinoid medicines. Patient access will expand regardless of research outcomes. As of May 2026, 38 states operate medical cannabis programs, and 24 states have legalized adult-use cannabis. IBD patients in these states can access products without waiting for clinical trial results, though without insurance coverage or physician dosing guidance. This creates a parallel market where research informs but does not control patient behavior. Key decision points over the next 24 months include: DEA finalization of the cannabis rescheduling NPRM (expected late 2026), FDA issuance of final guidance on cannabis clinical trials (expected mid-2027), publication of interim results from the New York trials (expected early 2028), and potential FDA approval of the first cannabis-based IBD therapy (earliest possible date 2029-2030 if a company began Phase III trials in 2026).

Further Reading

• New York Marihuana Regulation and Taxation Act (Cannabis Law Article 4) — full statutory text at https://cannabis.ny.gov/law-and-regulations
• Controlled Substances Act, 21 U.S.C. § 812 — federal scheduling framework at https://www.deadiversion.usdoj.gov/21cfr/21usc/812.htm
• Naftali T, et al. "Cannabis induces a clinical response in patients with Crohn's disease: a prospective placebo-controlled study." Clinical Gastroenterology and Hepatology 2013;11(10):1276-1280 — https://www