Cannabis study reveals how THC and CBD impact impairment and drug tests
NCT ID NCT05037487
First seen Jun 27, 2026 · Last updated Jun 27, 2026
Summary
This completed Phase 1 study at UCLA looked at how smoking cannabis with different amounts of THC and CBD affects drug levels in oral fluid and blood, as well as thinking and feeling. Nineteen adults who use cannabis occasionally took part. The goal was to better understand how to detect recent cannabis use and measure its effects on the brain.
What this could mean
Our plain-language read of the trial. This is informational only, not medical advice or a prediction.
- Active substance
- Smoked cannabis with varying amounts of THC and CBD
- What this could lead to
- If successful, this research could improve roadside drug testing and help understand how different cannabis components affect impairment.
- What could go wrong
- This is a small, early-phase study with only 19 participants, so results may not apply to everyone. It focuses on measurement, not treatment.
This is an AI summary of the original study and may miss details. Read our disclaimer.
Study facts
What this study's own registry entry says, in plain language.
- Phase
-
Phase 1
The first testing in people. Mainly checks safety and dose, usually in a small group.
- Participants
-
19 people
The number who actually took part.
- Started
-
Sep 2022
- Finished
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Jun 2025
- Lead sponsor
-
Other sponsor
The registry's catch-all category, for sponsors it does not file as a company, a government agency, or a research network.
Who can take part
This study's own entry requirements. Only the study team can say for certain whether you qualify.
- Ages
-
21 to 55 years
- Sex
-
Anyone
- Healthy volunteers
-
Accepted
You do not need to have the condition being studied to take part.
Show the full entry requirements Hide the full entry requirements
Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.
Inclusion Criteria: * Male or non-pregnant and non-lactating females aged 21-55 years * Report weekly-monthly use of cannabis (≤1 day per week) over the past month prior to screening, * 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 moderate to severe Cannabis Use disorder (CUD) or any substance use disorder other than nicotine, caffeine * Any other Axis I disorder * Report using other illicit drugs in the prior 4 weeks, other than cannabis. * Current use of any medications that may affect study outcomes * If medical history, physical and psychiatric examination, or laboratory tests performed during the screening process are not within the normal range and / or reveal any significant illness (e.g., hypertension) as judged by the study physician and to put the participant at greater risk of experiencing adverse events due to completion of study procedures. * Pregnancy is exclusionary due to the possible effects of the study medication on fetal development. * History of an allergic reaction or adverse reaction to cannabis is exclusionary. * History of respiratory illness or current respiratory illness * Currently enrolled in another research protocol * Not using a contraceptive method (hormonal or barrier methods) * The evaluating physician reviews all medical assessments along with medical history. Any disorders that might make cannabis administration hazardous are exclusionary.
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Conditions
The condition(s) this trial relates to.
As listed by the trial registrant
The condition terms exactly as the trial's registrant entered them.
Contacts and locations
Locations
-
University of California, Los Angeles
Los Angeles, California, 90095, United States
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