High Potency Cannabis: Acute and Protracted Effects (HIGH-CAP)

The purpose of this research is to assess the effects of smoked cananbis when cannabis is smoked during periods of cannabis use as usual and after a brief period of abstinence.

Study Overview

• Status: Recruiting
• Conditions: Pain; Pharmacokinetics; Abuse Cannabis
• Intervention / Treatment: Drug: Placebo Comparator: Placebo; Drug: Low dose THC; Drug: High dose THC

Detailed Description

This outpatient study will assess the acute pharmacodynamic effects of smoked cannabis with ~50 mg and ~100 mg THC compared to placebo (~0 mg THC) and whether a brief period of abstinence alters these effects. Metabolism (pharmacokinetics) of THC will be examined to associate behavioral and physiological effects to plasma concentrations of THC and metabolites.

• Study Type: Interventional
• Enrollment (Estimated): 30
• Phase: Phase 1

Contacts and Locations

• Study Contact: Name: Vincent Acebo; Phone Number: 310-983-3417; Email: vacebo@mednet.ucla.edu
• Study Contact Backup: Name: Ziva Cooper, PhD; Phone Number: 310-206-9942; Email: cannabislab@mednet.ucla.edu

Study Locations

• United States
  • California
    • Los Angeles, California, United States, 90095
      • Recruiting
      • UCLA Center for Cannabis and Cannabinoids
      • Contact: Vincent Acebo; Phone Number: 310-983-3417; Email: vacebo@mednet.ucla.edu

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• • Male or non-pregnant and non-lactating females aged 21-55 years

  • Report cannabis smoking near daily
  • Not currently seeking treatment for their cannabis use
  • Have a Body Mass Index from 18.5 - 34kg/m2.
  • Able to perform all study procedures
  • Must be using a contraceptive (hormonal or barrier methods)

Exclusion Criteria:

• Meeting DSM-V criteria for any substance use disorder other than cannabis, nicotine, caffeine
• Do not have positive urine toxicology for cannabis use during screening
• Evidence of severe psychiatric illness (e.g. mood or anxiety disorder with functional impairment or suicide risk, schizophrenia) judged by the study physician (and PI) to put the participant at greater risk of experiencing adverse events due to completion of study procedures, interfere with their ability to participate in the study, or their capacity to provide informed consent.
• Report using other illicit drugs in the prior 4 weeks
• Current predominant licit use of medical cannabis, prescription analgesics, or any medications that may affect study outcomes
• Current pain
• Pregnancy
• Currently enrolled in another research protocol
• Not using a contraceptive method (hormonal or barrier methods)
• Insensitivity to the cold water stimulus of the Cold Pressor Test
• Any disorders that might make cannabis administration hazardous as determined by evaluation physician after review of all medical assessments along with medical history.
• Not able to speak and read English

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: Double

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Placebo Comparator: Placebo Comparator: Placebo; 0 mg THC	Drug: Placebo Comparator: Placebo; Placebo; Other Names: Cannabis
Active Comparator: Low dose THC; 50 mg THC	Drug: Low dose THC; Smoked low dose THC; Other Names: Cannabis
Active Comparator: High dose THC; 100 mg THC	Drug: High dose THC; Smoked high dose THC; Other Names: Cannabis

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Subject-rated drug effects of abuse liability	Subject ratings of "Good Drug Effect" as measured using a visual analog scale (1-100 mm)	3 hours
Analgesia as measured using the Cold Pressor Test	Pain threshold assessed using the Cold Pressor Test (percent baseline)	3 hours

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Pharmacokinetics of THC and metabolites	Peak plasma levels of THC (ng/ml)	3 hours
Pharmacokinetics of THC and metabolites	Peak plasma levels of 11-OH-THC (ng/ml)	3 hours

Collaborators and Investigators

• Sponsor: University of California, Los Angeles
• Collaborators: California Department of Cannabis Control (DCC)

Study record dates

Study Major Dates

• Study Start (Actual): July 3, 2025
• Primary Completion (Estimated): July 1, 2027
• Study Completion (Estimated): July 1, 2028

Study Registration Dates

• First Submitted: February 25, 2025
• First Submitted That Met QC Criteria: March 3, 2025
• First Posted (Actual): March 5, 2025

Study Record Updates

• Last Update Posted (Actual): September 4, 2026
• Last Update Submitted That Met QC Criteria: September 3, 2026
• Last Verified: September 1, 2026

More Information

Terms related to this study

• Keywords: Cannabis; THC
• Additional Relevant MeSH Terms: Neurologic Manifestations; Mental Disorders; Substance-Related Disorders; Chemically-Induced Disorders; Pathological Conditions, Signs and Symptoms; Signs and Symptoms; Pain; Marijuana Abuse; Organic Chemicals; Hydrocarbons; Terpenes; Cannabinoids; Dronabinol; nabiximols
• Other Study ID Numbers: 24-5316; 93304 (Other Grant/Funding Number: CA Department of Cannabis Control)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: Yes
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No