You will receive up to $1,400 for completing the study


You may be eligible to take part in this study if you

  • Are 21-45 years old, weigh between 130 and 250 lbs., and healthy;
  • Are not taking any medications, dietary/herbal supplements, or fruit juices that can interfere with your ability to eliminate kratom and the study drug;
  • Are willing to abstain from cannabis/marijuana, hemp, THC, and CBD products for several weeks;
  • Are willing to abstain from consuming caffeine-containing products and beverages the evening before and the morning of each study day;
  • Are willing to abstain from consuming any alcoholic beverages for at least 1 day prior to any study day and during the study day;
  • Are willing to use an additional method of non-hormonal contraception (such as abstinence, copper IUD, condom);
  • Have consumed kratom and opioids previously and tolerated it well without unpleasant effects and are willing to abstain from taking it for at least two weeks prior to and for the duration of the study; and
  • Have the time to participate.

You will not be eligible to take part in this study if you

  • Have a chronic illness or major psychiatric illness;
  • Have a hematologic (blood) disorder;
  • Have a history of any substance abuse, addiction, or dependence;
  • Are pregnant or breastfeeding;
  • Have a history of intolerance or allergy to kratom or opioid analgesics;
  • Have a need for chronic opioid analgesics or an imminent likely need for opioid analgesics (e.g., planned dental or surgical procedure);
  • Have used opioid analgesics 3 weeks prior to initiation of the study;
  • Have ever used amphetamines, benzodiazepines, cocaine, MDMA, opioids, PCP, or other drugs for recreational purposes;
  • Have used cannabis/marijuana, hemp, CBD- and/or THC-containing products within the past month;
  • Are taking concomitant medications, both prescription and non-prescription (including dietary supplements/herbal products), known to alter the pharmacokinetics of either the study drug or kratom; and/or
  • Are unable to speak, read, and understand English.

The Washington State University College of Pharmacy and Pharmaceutical Sciences is conducting this research study through funding provided by the National Institutes of Health.

For more information about this study, please contactdeena.hadi@wsu.edu