THCTHC TitrationNCT07105449
THC Titration of High-Potency Cannabis Concentrates
A study testing Cannabis (30% THC Concentrate), Cannabis (60% THC Concentrate) and Cannabis (90% THC Concentrate) in people with THC, run by Centre for Addiction and Mental Health at 1 site in Canada.
Trial summary
High-potency cannabis use is associated with public health risks, such as cannabis use disorder, psychotic disorders, and impaired cognition. Legal markets in the US and Canada are geared towards the commercialization of high-tetrahydrocannabinol (THC) products, including concentrates as high as 90-95%. Read more about this study
- Who is it for?
- Ages 19 to 55 yearsHealthy volunteers can take part
- Conditions the study is for
- THC
- What is being tested?
- Cannabis (30% THC Concentrate), Cannabis (60% THC Concentrate) and Cannabis (90% THC Concentrate)
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 48 participants
- Where
- 1 siteCanada
- Study dates
- 1 Oct 2025to 30 Sep 2028
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 19 to 55 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- Age 19-55 years.
- Frequency of primary exposure to cannabis 1-4 occasions per week, through any route of administration, over the past three months; participants must report experience with vaping high-potency liquid concentrates with more than 3 exposures to 90% THC and willingness to use such products in the study.
- Refrain from cannabis for 48 hours and from alcohol for 12 hours before visits.
- Agree not to drive a car for 24 hours after each visit.
- Abstain from recreational drugs for at least 48 hours prior to each visit.
- Abstain from any drugs not medically required.
- Well-controlled blood pressure for participants with hypertension.
Who cannot join
- Pregnant/breastfeeding (women of childbearing potential must have a negative pregnancy test and report use of appropriate contraception).
- Evidence of cardiac arrhythmias/failure, ischaemic heart disease.
- Recent open heart/open chest surgery or cataract surgery.
- Evidence from Structured Clinical Interview for DSM-5 [SCID-5-CT] or clinical evaluation of lifetime psychotic disorder/schizophrenia or bipolar disorder; family history of a first-degree relative with a diagnosis of psychotic disorder or schizophrenia; history of psychiatric co-morbidities in the past year (major depression, anxiety disorder or suicide attempt in past year or current suicidal ideation) and current substance use disorder/dependence.
- Evidence of neurological illness (e.g., stroke, epilepsy, traumatic brain injury).
- Renal or hepatic abnormalities (self-report and blood hematology/chemistry); and
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- Respiratory diseases, including asthma and physician-diagnosed lung disease.
- Taking prescribed medications that contain either THC or cannabidiol (CBD).
- Participation in another clinical or non-therapeutic study in the last three months.
- Bleeding disorders.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Canada1 site, 1 recruiting
- Recruiting
Centre for Addiction and Mental Health
Toronto, Ontario, M5T 1R8
Sergio Rueda, PhD, 416-535-8501 ext. 30742, sergio.rueda@camh.ca
Victor Tang, MD, 416-535-8501 ext. 39137, victor.tang@camh.ca
About this study
Official title: THC Titration of High-Potency Cannabis Concentrates: A Randomized Cross-Over Trial
High-potency cannabis use is associated with public health risks, such as cannabis use disorder, psychotic disorders, and impaired cognition. Legal markets in the US and Canada are geared towards the commercialization of high-tetrahydrocannabinol (THC) products, including concentrates as high as 90-95%. The cannabis industry has resisted regulation of higher-potency products claiming that cannabis consumers naturally self-titrate their use, but the limited evidence to date suggests that even though consumers may use less cannabis as potency rises, consuming higher potency products still leads to greater THC consumption. The investigators will use a randomized crossover trial to evaluate the ability of 36 regular cannabis consumers (18 females and 18 males) to self-titrate the THC dose when vaping concentrates to achieve the desired psychoactive effects. The investigators will also characterize and compare the subjective, cognitive, physiological, and pharmacokinetic effects between cannabis concentrates of different potencies (30%, 60%, and 90% THC). Working with US scientists, the setting of this study will be Toronto, Canada, in the context of federal legalization of cannabis, unique access to cannabis products not available in the US for research purposes, and an encouraging regulatory environment. The investigators will test commercial products that are representative of the THC ranges available in the legal market. Aim 1: To evaluate the ability of regular cannabis consumers to self-titrate their THC dose when vaping concentrates of different potencies. The investigators will compare markers of titration (biological: THC blood levels; behavioral: inhalation topography; subjective: self-reported levels of intoxication) over a range of potencies for a comprehensive characterization of titration practice. The investigators hypothesize that participants will be able to partially but not proportionally reduce THC intake with increase in THC potency. In other words, the investigators anticipate that the proportional decrease in blood THC levels will be lower than the proportional increase in THC concentrations. Aim 2: To compare the cognitive impairment, physiological effects, and addiction liability of consuming lower versus higher THC potency concentrates. The investigators hypothesize that cognitive impairment and physiological effects will be less pronounced with lower-THC concentrates in a dose-response fashion. The investigators will also explore differences in addiction liability between potencies as higher THC concentrations may result in greater dysphoric reactions. These acute effects may be related to long term harms such as accidents, CVD events, and CUD. Exploratory Aim: To explore sex differences in titration efficiency, blood THC concentrations, cognitive impairment, physiological effects, and addiction liability. The investigators propose to analyze sex differences in our primary and secondary outcomes (e.g., whether females will be able to titrate more efficiently than males). This experimental evidence will provide data on the potential acute harms related to concentrates and inform policy decisions on the need to decrease access and/or prevent their initiation and implement information and education campaigns to increase awareness on the risks of using them.
- Conditions
- THC
- Being tested
- Cannabis (30% THC Concentrate), Cannabis (60% THC Concentrate), Cannabis (90% THC Concentrate)
- Keywords
- Cannabis, THC Concentrates, Self-Titration, Subjective Effects, Cognition, THC
- Medical subject headings
- Marijuana Abuse
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Cannabis (30% THC Concentrate)Drug
Participants will vape 30% THC concentration of liquid cannabis ad libitum.
Cannabis (60% THC Concentrate)Drug
Participants will vape 60% THC concentration of liquid cannabis ad libitum.
Cannabis (90% THC Concentrate)Drug
Participants will vape 90% THC concentration of liquid cannabis ad libitum.
| Study group | Role | What they receive |
|---|---|---|
| Liquid Cannabis Concentrate (30% THC) | Experimental | Not described Receives: Drug: Cannabis (30% THC Concentrate) |
| Liquid Cannabis Concentrate (60% THC) | Experimental | Not described Receives: Drug: Cannabis (60% THC Concentrate) |
| Liquid Cannabis Concentrate (90% THC) | Experimental | Not described Receives: Drug: Cannabis (90% THC Concentrate) |
What is being measured
The primary outcome is the main question the study is designed to answer.
Pharmacokinetics (blood levels of THC and metabolites)
Blood concentrations (ng/mL) of THC, 11-hydroxy-Δ9-tetrahydrocannabinol (OH-THC), and 11-Nor-9-carboxy-Δ9-tetrahydrocannabinol (THC-COOH) will be collected for measurement of THC and metabolites.
Information and comparison of the PK parameters of THC and its metabolites for each product
Measured: Before vaping, 5-min after first inhalation, and at 5-, 30-, and at 60-minute intervals until 4 hours after vaping.
Inhalation Topography
Number of puffs will be measured using the eTop device.
Measured: During a 10-minute vaping session, participants will be asked to consume cannabis ad libitum.
Inhalation Topography
puff volume (cm^3) will be measured using the eTop device.
Measured: During a 10-minute vaping session, participants will be asked to consume cannabis ad libitum
Inhalation Topography
puff duration (milliseconds and seconds)
Measured: During a 10-minute vaping session, participants will be asked to consume cannabis ad libitum.
Inhalation Topography
inter and inter-puff intervals (seconds and minutes) will be measured using the eTop device
Measured: During a 10-minute vaping session, participants will be asked to consume cannabis ad libitum.
Secondary outcomes (11)
Visual Analog Scales (VAS)
A series of Visual Analog Scales (VAS) (ranging from 0 - 100) measuring subjective effects related to liking, high, good/bad effects, and rush. Minimum total score = 0, maximum total score = 2400.
Higher/lower scores are item dependent, therefor total score is not indicative of better/worse outcome.
Measured: Before vaping, 5-min after first inhalation, and at 5-, 30-, and at 60-minute intervals until 4 hours after vaping.
Profile of Mood States (POMS)
Used to measure high/intoxication and pleasant/unpleasant cannabis effects.
Measured: Before vaping, and 1 hour and 2 hours after vaping.
Addiction Research Centre Inventory (ARCI)
Used to assess subjective effects of cannabis.
Measured: 1 hour and 2 hours after vaping
Cognitive Task - Sustained Attention
CANTAB's Rapid Visual Information Processing test asks participants to monitor a changing series of digits and to respond only when a target sequence of digits is presented.
Measured: Before vaping and 60 minutes after vaping.
Cognitive Task - Visuo-Spatial Working Memory
CANTAB's Spatial Working Memory test examines the maintenance and manipulation of visuospatial information.
Measured: Before vaping and 60 minutes after vaping.
Cognitive Task - Psychomotor Speed/Accuracy
CANTAB's Cognition Kit Digit Symbol Substitution (DSST) measures rapid information processing of symbols under a time limit and has been shown to be particularly sensitive to acute cannabis administration.
Measured: Before vaping and 60 minutes after vaping.
Physiological Effect - Heart Rate
Heart rate (bpm) will be measured.
Measured: Before vaping, 5-min after first inhalation, and at 5-, 30-, and at 60-minute intervals until 4 hours after vaping.
Physiological Effect - Blood Pressure
Systolic and diastolic blood pressure (mmHg) will be measured.
Measured: Before vaping, 5-min after first inhalation, and at 5-, 30-, and at 60-minute intervals until 4 hours after vaping.
Perceived Cannabis Effects Questions
A questionnaire used to assess the perceived effects of cannabis.
Measured: 5 hours After vaping.
Pharmacogenetic Variations
Following DNA extraction, genomic DNA will be genotyped using established methods to conduct pharmacogenomics assessments. Examples of genes with known or hypothesized roles in THC metabolism and/or response include CYP2C9 and CNR1, as well as those identified in genome-wide association studies of cannabis use traits (e.g. CHRNA2).
Measured: 10 minutes before vaping
Sex/Gender
Traditional Masculinity-Femininity Scale (TMF)
Measured: During baseline, prior to vaping
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted6 Aug 2025
- Study start1 Oct 2025
- Primary completion31 Mar 2028 (estimated)
- Study completion30 Sep 2028 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for THCStudies of the same condition, open and under way.
- More trials run by Centre for Addiction and Mental HealthThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Other
- Allocation
- Randomised
- Intervention model
- Crossover
- Model description
- This study is a double blind, randomized, cross-over human laboratory experiment evaluating the ability of participants who regularly consume cannabis to self-titrate their THC dose when vaping high-THC liquid concentrates of different potencies (30%, 60%, 90% THC).
- Masking
- Triple blind
- Who is masked
- Participant, Investigator, Outcomes assessor
- Enrolment
- 48 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Centre for Addiction and Mental Health
- Sponsor type
- University, hospital or other
- Collaborators
- National Institute on Drug Abuse (NIDA)
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07105449
- Sponsor's protocol ID
- 2024-085
- Other IDs
- 1R21DA061350-01, 195858
- Acronym
- THC Titration
- Status last verified
- Jun 2026
- First submitted
- 27 May 2025
- Last updated
- 11 Jun 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 11 Jun 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- THC Titration of High-Potency Cannabis Concentrates: A Randomized Cross-Over Trial
- ClinicalTrials.gov ID
- NCT07105449
- Acronym / sponsor ID
- THC Titration / 2024-085
- Conditions
- THC
- Keywords
- Cannabis, THC Concentrates, Self-Titration, Subjective Effects, Cognition, THC
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 48 participants (estimated)
- Lead sponsor
- Centre for Addiction and Mental HealthUniversity, hospital or other
- Collaborators
- National Institute on Drug Abuse (NIDA)
- Study start
- 1 Oct 2025 (actual)
- Primary completion
- 31 Mar 2028 (estimated)
- Study completion
- 30 Sep 2028 (estimated)
- First posted
- 6 Aug 2025 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
High-potency cannabis use is associated with public health risks, such as cannabis use disorder, psychotic disorders, and impaired cognition. Legal markets in the US and Canada are geared towards the commercialization of high-tetrahydrocannabinol (THC) products, including concentrates as high as 90-95%. The cannabis industry has resisted regulation of higher-potency products claiming that cannabis consumers naturally self-titrate their use, but the limited evidence to date suggests that even though consumers may use less cannabis as potency rises, consuming higher potency products still leads to greater THC consumption. The investigators will use a randomized crossover trial to evaluate the ability of 36 regular cannabis consumers (18 females and 18 males) to self-titrate the THC dose when vaping concentrates to achieve the desired psychoactive effects. The investigators will also characterize and compare the subjective, cognitive, physiological, and pharmacokinetic effects between cannabis concentrates of different potencies (30%, 60%, and 90% THC). Working with US scientists, the setting of this study will be Toronto, Canada, in the context of federal legalization of cannabis, unique access to cannabis products not available in the US for research purposes, and an encouraging regulatory environment. The investigators will test commercial products that are representative of the THC ranges available in the legal market. Aim 1: To evaluate the ability of regular cannabis consumers to self-titrate their THC dose when vaping concentrates of different potencies. The investigators will compare markers of titration (biological: THC blood levels; behavioral: inhalation topography; subjective: self-reported levels of intoxication) over a range of potencies for a comprehensive characterization of titration practice. The investigators hypothesize that participants will be able to partially but not proportionally reduce THC intake with increase in THC potency. In other words, the investigators anticipate that the proportional decrease in blood THC levels will be lower than the proportional increase in THC concentrations. Aim 2: To compare the cognitive impairment, physiological effects, and addiction liability of consuming lower versus higher THC potency concentrates. The investigators hypothesize that cognitive impairment and physiological effects will be less pronounced with lower-THC concentrates in a dose-response fashion. The investigators will also explore differences in addiction liability between potencies as higher THC concentrations may result in greater dysphoric reactions. These acute effects may be related to long term harms such as accidents, CVD events, and CUD. Exploratory Aim: To explore sex differences in titration efficiency, blood THC concentrations, cognitive impairment, physiological effects, and addiction liability. The investigators propose to analyze sex differences in our primary and secondary outcomes (e.g., whether females will be able to titrate more efficiently than males). This experimental evidence will provide data on the potential acute harms related to concentrates and inform policy decisions on the need to decrease access and/or prevent their initiation and implement information and education campaigns to increase awareness on the risks of using them.
Study design
- Primary purpose
- Other
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Triple blind (participant, investigator, outcomes assessor)
- Number of arms
- 3
- Model description
- This study is a double blind, randomized, cross-over human laboratory experiment evaluating the ability of participants who regularly consume cannabis to self-titrate their THC dose when vaping high-THC liquid concentrates of different potencies (30%, 60%, 90% THC).
| Arm | Type | Receives |
|---|---|---|
| Liquid Cannabis Concentrate (30% THC) | Experimental | Drug: Cannabis (30% THC Concentrate) |
| Liquid Cannabis Concentrate (60% THC) | Experimental | Drug: Cannabis (60% THC Concentrate) |
| Liquid Cannabis Concentrate (90% THC) | Experimental | Drug: Cannabis (90% THC Concentrate) |
Who may qualify
- Ages
- 19 to 55 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (7 listed)
- Age 19-55 years.
- Frequency of primary exposure to cannabis 1-4 occasions per week, through any route of administration, over the past three months; participants must report experience with vaping high-potency liquid concentrates with more than 3 exposures to 90% THC and willingness to use such products in the study.
- Refrain from cannabis for 48 hours and from alcohol for 12 hours before visits.
- Agree not to drive a car for 24 hours after each visit.
- Abstain from recreational drugs for at least 48 hours prior to each visit.
Key exclusion criteria (10 listed)
- Pregnant/breastfeeding (women of childbearing potential must have a negative pregnancy test and report use of appropriate contraception).
- Evidence of cardiac arrhythmias/failure, ischaemic heart disease.
- Recent open heart/open chest surgery or cataract surgery.
- Evidence from Structured Clinical Interview for DSM-5 [SCID-5-CT] or clinical evaluation of lifetime psychotic disorder/schizophrenia or bipolar disorder; family history of a first-degree relative with a diagnosis of psychotic disorder or schizophrenia; history of psychiatric co-morbidities in the past year (major depression, anxiety disorder or suicide attempt in past year or current suicidal ideation) and current substance use disorder/dependence.
- Evidence of neurological illness (e.g., stroke, epilepsy, traumatic brain injury).
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Cannabis (30% THC Concentrate)Participants will vape 30% THC concentration of liquid cannabis ad libitum. | Drug | Liquid Cannabis Concentrate (30% THC) |
| Cannabis (60% THC Concentrate)Participants will vape 60% THC concentration of liquid cannabis ad libitum. | Drug | Liquid Cannabis Concentrate (60% THC) |
| Cannabis (90% THC Concentrate)Participants will vape 90% THC concentration of liquid cannabis ad libitum. | Drug | Liquid Cannabis Concentrate (90% THC) |
Primary outcome
Pharmacokinetics (blood levels of THC and metabolites)
Time frame: Before vaping, 5-min after first inhalation, and at 5-, 30-, and at 60-minute intervals until 4 hours after vaping.
Blood concentrations (ng/mL) of THC, 11-hydroxy-Δ9-tetrahydrocannabinol (OH-THC), and 11-Nor-9-carboxy-Δ9-tetrahydrocannabinol (THC-COOH) will be collected for measurement of THC and metabolites. Information and comparison of the PK parameters of THC and its metabolites for each product
Inhalation Topography
Time frame: During a 10-minute vaping session, participants will be asked to consume cannabis ad libitum.
Number of puffs will be measured using the eTop device.
Inhalation Topography
Time frame: During a 10-minute vaping session, participants will be asked to consume cannabis ad libitum
puff volume (cm^3) will be measured using the eTop device.
Inhalation Topography
Time frame: During a 10-minute vaping session, participants will be asked to consume cannabis ad libitum.
puff duration (milliseconds and seconds)
Inhalation Topography
Time frame: During a 10-minute vaping session, participants will be asked to consume cannabis ad libitum.
inter and inter-puff intervals (seconds and minutes) will be measured using the eTop device
11 secondary outcomes
Visual Analog Scales (VAS)
Time frame: Before vaping, 5-min after first inhalation, and at 5-, 30-, and at 60-minute intervals until 4 hours after vaping.
Profile of Mood States (POMS)
Time frame: Before vaping, and 1 hour and 2 hours after vaping.
Addiction Research Centre Inventory (ARCI)
Time frame: 1 hour and 2 hours after vaping
Cognitive Task - Sustained Attention
Time frame: Before vaping and 60 minutes after vaping.
Cognitive Task - Visuo-Spatial Working Memory
Time frame: Before vaping and 60 minutes after vaping.
Cognitive Task - Psychomotor Speed/Accuracy
Time frame: Before vaping and 60 minutes after vaping.
Physiological Effect - Heart Rate
Time frame: Before vaping, 5-min after first inhalation, and at 5-, 30-, and at 60-minute intervals until 4 hours after vaping.
Physiological Effect - Blood Pressure
Time frame: Before vaping, 5-min after first inhalation, and at 5-, 30-, and at 60-minute intervals until 4 hours after vaping.
Perceived Cannabis Effects Questions
Time frame: 5 hours After vaping.
Pharmacogenetic Variations
Time frame: 10 minutes before vaping
Sex/Gender
Time frame: During baseline, prior to vaping
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 11 Jun 2026.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Cannabis (30% THC Concentrate), Cannabis (60% THC Concentrate) and Cannabis (90% THC Concentrate) in people with THC, run by Centre for Addiction and Mental Health at 1 site in Canada.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 7 inclusion and 10 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 11 Jun 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Canada. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Sergio Rueda, PhD (416-535-8501 ext. 30742, sergio.rueda@camh.ca), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Pharmacokinetics (blood levels of THC and metabolites) (time frame: Before vaping, 5-min after first inhalation, and at 5-, 30-, and at 60-minute intervals until 4 hours after vaping.). The study lists 5 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 11 Jun 2026.