Recruiting

Kratom

Sponsor:

Johns Hopkins University

Code:

NCT06089980

Conditions

Kratom Pharmacokinetics

Kratom Pharmacodynamics

Kratom

Eligibility Criteria

Sex: All

Age: 21+

Healthy Volunteers: Accepted

Interventions

Effects from acute kratom exposure

Study Details

Brief 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. 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.

Conditions

Kratom Pharmacokinetics

Kratom Pharmacodynamics

Kratom

Study ID

NCT06089980

Start date

Apr 1, 2024

Status verified date

Jan, 2026

Completion date

Feb, 2028

Anticipated

Primary completion date

Feb, 2028

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 21+

Healthy Volunteers: Accepted

INCLUSION CRITERIA:

1. >21 years
2. reporting kratom use >5 times per week for >3 months prior to study screening
3. English language proficiency
4. Willingness to provide requested samples of the kratom product being currently taken

EXCLUSION CRITERIA:

1. Reports any acute adverse, unexpected, or otherwise sudden health event related to the typical kratom product dose that occurred within 30 days of screening
2. Having ever sought medical attention for an acute adverse health event as a result of taking any kratom product.
3. 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.
4. Self-reports using kratom products by any other route than orally swallowing.
5. Current physical dependence on alcohol, benzodiazepines, or opioids
6. Reports use of fentanyl within the past month and/or has a fentanyl positive drug screen.
7. Discordance between self-reported substance use and drug screen results obtained during screening.
8. Lifetime or current psychotic disorder
9. Current untreated major depressive or bipolar disorder
10. Pregnancy or nursing
11. Physical, psychiatric, or environmental conditions considered by study team to increase risk or undue burden (e.g., untreated hypertension, high BMI, etc.).

Study Design

Enrollment

22 participants

Anticipated

Interventions and Outcome Measures

Arms

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.

Interventions

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 measure

  • Peak subjective opioid withdrawal score [ Time Frame: Up to 3 days ]
  • Time in minutes until a Subjective Opioid Withdrawal (SOWS) score of more than 11 is reached [ Time Frame: up to 3 days ]
  • Peak rating and changes in rating on Drug Effects Questionnaire (primary subjective outcome) [ Time Frame: Up to 3 days ]
  • Peak rating and change in rating on Drug Effects Questionnaire (primary subjective outcome) [ Time Frame: Up to 3 days ]
  • Changes in accuracy on psychomotor task (primary cognitive outcome) [ Time Frame: Up to 3 days ]
  • Pupil diameter nadir size as measured in millimeters (mm) (primary physiological outcome). [ Time Frame: Up to 3 days ]

Central Contacts and Locations

Central contacts

Kirsten E Smith, Ph.D.

865-418-8177ksmit398@jh.edu

Naftali Zeilinger, B.A.

410-550-0490nzeilin1@jh.edu

Locations

Johns Hopkins University

Recruiting

Baltimore, Maryland, United States, 21224

Contacts

Kirsten E Smith, Ph.D.

865-418-8177ksmit398@jh.edu

Naftali Zeilinger, B.A.

(410) 870-9227nzeilin1@jh.edu

Principal Investigator:

Kirsten E Smith, Ph.D.

More Information

Sponsor

Johns Hopkins University

Last update posted

Jan 23, 2026

Last verified

Jan, 2026

Keywords

  • kratom

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-10. This information was provided to ClinicalTrials.gov by Johns Hopkins University on 2026-01-23.