NIH clears kratom compound for first human opioid trial

Federal scientists cleared the way for the first human study of mitragynine, the main psychoactive compound in kratom, as the United States continues to struggle with deadly opioid use and too few accessible treatments. The National Institutes of Health said on June 1, 2026, that the Food and Drug Administration had allowed its Investigational New Drug application to take effect, a regulatory step that lets researchers begin testing the compound in people under federal oversight.

The NIH-led phase I trial, listed on ClinicalTrials.gov as NCT07204171 and titled Phase 1 Study of Oral MG001, will enroll about 32 healthy adult volunteers, both men and women. It will use a randomized, double-blind, placebo-controlled, single-ascending-dose design, with participants watched in a clinic for three nights through Day 4 and then brought back for a Day 7 follow-up. The study is not yet recruiting. NIH said the purified formulation was developed by its scientists and University of Florida researchers, with preclinical work supporting the application.

The move matters because kratom has become a point of hope and controversy in the opioid crisis. People have reported using it for opioid withdrawal, pain, fatigue and mental health problems, and NIDA says kratom can produce opioid-like and stimulant-like effects. At the same time, the institute warns that rare but serious problems have been reported, including psychiatric, cardiovascular, gastrointestinal and respiratory effects, and there are no FDA-approved uses for kratom. That leaves patients, clinicians and regulators with a familiar dilemma: a substance drawing attention in the absence of better options, but still lacking the human evidence needed to judge whether it helps more than it harms.

NIH framed the study as part of the HEAL Initiative, the agency-wide effort launched in April 2018 to improve prevention and treatment strategies for opioid misuse and addiction and to strengthen pain management. The FDA says an IND is the mechanism that allows a sponsor to test an investigational drug in humans, and the early goal is to determine whether it is reasonably safe for first use. For mitragynine, that means the first formal step from laboratory promise toward clinical reality will focus on safety and tolerability, not proof of benefit.

Interest in kratom compounds has grown far beyond the labs in Gainesville, Florida, and the NIH decision was quickly welcomed by the American Kratom Association on June 2. For now, the significance is not that kratom has been endorsed as a treatment, but that researchers can finally begin answering whether mitragynine deserves a place in the next generation of opioid research.