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NCT Number: NCT06089980

Direct Observation Study of Kratom Product Effects Among Regular Consumers

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.

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Key information

Conditions

Kratom Pharmacokinetics Kratom Kratom Pharmacodynamics

Age range

21 year and older

Sex eligibility

All sexes

Study type

Observational

Primary location

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • >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

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.).

Treatment and study plan

Effects from acute kratom exposure

Behavioral

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 outcomes

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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

Study contacts

Contact information is provided by the study sponsor or research team.

Kirsten E Smith, Ph.D.

CONTACT

[email protected]

865-418-8177

Naftali Zeilinger, B.A.

CONTACT

[email protected]

410-550-0490

Sponsors and collaborators

Lead sponsor

Johns Hopkins University

Other

Collaborators

  • National Institute on Drug Abuse (NIDA)
  • University of Florida

Registry information

Official study title

Observing the Acute Effects Following a Single Oral Dose of Kratom and Effects Following Kratom Cessation Among Adults Who Use Regularly.

Important dates

Study start
2024
Primary completion
2028
Study completion
2028
First posted
Oct 19, 2023
Registry last updated
Jan 23, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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