NCT06089980 · Johns Hopkins University
Direct Observation Study of Kratom Product Effects Among Regular Consumers
What this study is about
The goal of this observational clinical study is to is to learn more about how commercial kratom products affect healthy adults who consume them regularly. The main questions it aims to answer are: 1.
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The goal of this observational clinical study is to is to learn more about how commercial kratom products affect healthy adults who consume them regularly. The main questions it aims to answer are: 1. What are the acute physiological, subjective, and cognitive effects of kratom following participant self-administration of a single oral dose of the participants usual kratom product at the participants typical dose? 2. What are the physiological, subjective, and cognitive effects associated with kratom product discontinuation among adults who use regularly? 3. What are the pharmacokinetics of kratom products consumed by adults who use regularly? On the first study day: Under direct observation, participants will self-administer a single oral dose of the participants own commercial kratom product that that is regularly taken and will consume it at the participants self-selected typical dose/serving. Following this, serial blood draws and urine collection will occur along with administration of validated questionnaires, tests, and continual monitoring. After this first study day, participants will no longer be permitted to use any of the participants kratom product during the study. On study nights/days 2-3: participants will reside a clinical research unit and be observed and evaluated for kratom withdrawal syndrome.
Interventions
BEHAVIORAL
Effects from acute kratom exposure
Participants who regularly use commercial Kratom products will orally consume a known quantity of kratom under direct observation on first study day; following this, participants will stop kratom use for approximately 2 nights and 2.5 days for the duration of the study.
Primary outcome measures
Peak subjective opioid withdrawal score
Time frame: Up to 3 days
Peak score on the Subjective Opioid Withdrawal Scale (SOWS); that occurs between Study Days 1-3. Score range 0-64. 5-point scale of intensity: 0=not at all, 1=a little, 2=moderately, 3=quite a bit, 4=extremely. Higher score indicates higher intensity. SOWS will be administered at 8 time points on Study Days 1-2 and 7 time points on Study Day 3.
Time in minutes until a Subjective Opioid Withdrawal (SOWS) score of more than 11 is reached
Time frame: up to 3 days
Time, in minutes, until at least a moderate score (of 11 or higher) is reached on the Subjective Opioid Withdrawal Scale (SOWS). SOWS will be administered at 8 time points on Study Days 1-2 and 7 time points on Study Day 3. 5-point scale of intensity: 0=not at all, 1=a little, 2=moderately, 3=quite a bit, 4=extremely. Score range 0-64. Higher score indicates higher intensity.
Peak rating and changes in rating on Drug Effects Questionnaire (primary subjective outcome)
Time frame: Up to 3 days
Drug Effects Questionnaire (DEQ) visual analogue scale (0-100) rating for DEQ item "feeling high." The DEQ will be administered at 7 timepoints on Study Day 1 and at 6 times points on Study Days 2 and 3.
Peak rating and change in rating on Drug Effects Questionnaire (primary subjective outcome)
Time frame: Up to 3 days
Drug Effects Questionnaire (DEQ) visual analogue scale (0-100) rating for DEQ item "drug liking." The DEQ will be administered at 7 time points on Study Day 1 and at 6 times points on Study Days 2 and 3.
Changes in accuracy on psychomotor task (primary cognitive outcome)
Time frame: Up to 3 days
The 2-minute computerized Digit Symbol Substitution Task (DSST) outcome of total number of correct responses (accuracy) within the 2-minute test window. This will evaluate cognitive performance and impairment. The DSST will be administered at 7 time points on Study Day 1 and at 6 times points on Study Days 2 and 3.
Pupil diameter nadir size as measured in millimeters (mm) (primary physiological outcome).
Time frame: Up to 3 days
Pupil diameter in mm under stable light conditions using a pupilometer. Pupil size will be measured at 8 timepoints on Study Days 1 and 2 and at 7 timepoints on Study Day 3
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- reporting kratom use \>5 times per week for \>3 months prior to study screening
- English language proficiency
- Willingness to provide requested samples of the kratom product being currently taken
Exclusion criteria
- Reports any acute adverse, unexpected, or otherwise sudden health event related to the typical kratom product dose that occurred within 30 days of screening
- Having ever sought medical attention for an acute adverse health event as a result of taking any kratom product.
- Cannot or will not provide kratom product samples in the form of an unopened package of kratom that is clearly labeled with at least the product and vendor name.
- Self-reports using kratom products by any other route than orally swallowing.
- Current physical dependence on alcohol, benzodiazepines, or opioids
- Reports use of fentanyl within the past month and/or has a fentanyl positive drug screen.
- Discordance between self-reported substance use and drug screen results obtained during screening.
- Lifetime or current psychotic disorder
- Current untreated major depressive or bipolar disorder
- Pregnancy or nursing
- Physical, psychiatric, or environmental conditions considered by study team to increase risk or undue burden (e.g., untreated hypertension, high BMI, etc.).
Where
- Baltimore, Maryland
Collaborators
University of Florida, National Institute on Drug Abuse (NIDA)
Related conditions & keywords
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Jan 23, 2026 · Source of record for eligibility and locations