Kratom PharmacokineticsNCT06089980
Direct Observation Study of Kratom Product Effects Among Regular Consumers
An observational study of Kratom Pharmacokinetics and Kratom Pharmacodynamics, run by Johns Hopkins University at 1 site in United States.
Trial summary
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. Read more about this study
- Who is it for?
- Ages 21 years and olderHealthy volunteers can take part
- Conditions the study is for
- Kratom Pharmacokinetics, Kratom Pharmacodynamics, Kratom
- What is being tested?
- Effects from acute kratom exposure
- Type of treatment
- Pill or oral medicine, Lifestyle or therapy programme
- How many people
- 22 participants
- Where
- 1 siteUnited States
- Study dates
- 1 Apr 2024to Feb 2028
- Phase
- Observational
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 21 years and older
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Study population: Healthy adults aged 21 or older who use kratom.
Who may be able to join
- >21 years
- 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
Who cannot join
- 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.
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- 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.).
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
United States1 site, 1 recruiting
- Recruiting
Johns Hopkins University
Baltimore, Maryland, 21224
Kirsten E Smith, Ph.D., 865-418-8177, ksmit398@jh.edu
Naftali Zeilinger, B.A., (410) 870-9227, nzeilin1@jh.edu
About this study
Official title: Observing the Acute Effects Following a Single Oral Dose of Kratom and Effects Following Kratom Cessation Among Adults Who Use Regularly.
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:
- 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?
- What are the physiological, subjective, and cognitive effects associated with kratom product discontinuation among adults who use regularly?
- 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.
- Conditions
- Kratom Pharmacokinetics, Kratom Pharmacodynamics, Kratom
- Being tested
- Effects from acute kratom exposure
- Keywords
- kratom
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Effects from acute kratom exposureBehavioural
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.
| Study group | Role | What they receive |
|---|---|---|
| Acute kratom exposure | Participants who regularly consume kratom will orally self-administer a single serving of the participants commercial kratom product under direct observation in order to evaluate acute physiological, subjective, and cognitive effects and determine pharmacokinetics. This will occur during the first 24 hours of study participation. Participants will undergo direct observation and assessment for after ceasing all kratom product use. Physiological, subjective, and cognitive effects during this supervised withdrawal will be assessed. Receives: Behavioral: Effects from acute kratom exposure |
What is being measured
The primary outcome is the main question the study is designed to answer.
Peak subjective opioid withdrawal score
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.
Measured: Up to 3 days
Time in minutes until a Subjective Opioid Withdrawal (SOWS) score of more than 11 is reached
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.
Measured: up to 3 days
Peak rating and changes in rating on Drug Effects Questionnaire (primary subjective outcome)
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.
Measured: Up to 3 days
Peak rating and change in rating on Drug Effects Questionnaire (primary subjective outcome)
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.
Measured: Up to 3 days
Changes in accuracy on psychomotor task (primary cognitive outcome)
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.
Measured: Up to 3 days
Pupil diameter nadir size as measured in millimeters (mm) (primary physiological outcome).
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
Measured: Up to 3 days
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted19 Oct 2023
- Study start1 Apr 2024
- Primary completionFeb 2028 (estimated)
- Study completionFeb 2028 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Kratom PharmacokineticsStudies of the same condition, open and under way.
- More trials run by Johns Hopkins UniversityThe 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
- Observational
- Observational model
- Other
- Time perspective
- Prospective
- Enrolment
- 22 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Johns Hopkins University
- Sponsor type
- University, hospital or other
- Collaborators
- University of Florida, National Institute on Drug Abuse (NIDA)
- Responsible party
- Sponsor
- Investigators
- Kirsten E Smith, Ph.D., Principal investigator, Johns Hopkins University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06089980
- Sponsor's protocol ID
- IRB00408134
- Other IDs
- R00DA055571
- Status last verified
- Jan 2026
- First submitted
- 12 Oct 2023
- Last updated
- 23 Jan 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No