The National Institutes of Health has opened a long-awaited clinical question: can a purified compound from kratom be studied safely in people as a possible treatment for opioid use disorder? NIH announced on June 1, 2026, that its Investigational New Drug application for mitragynine has taken effect with the U.S. Food and Drug Administration.
The step allows NIH scientists to move toward a phase I clinical trial of mitragynine, the primary psychoactive compound in Mitragyna speciosa, the tropical tree commonly known as kratom. The planned study will focus first on safety and tolerability. Any future treatment claims would require later clinical testing.
That caution matters. Kratom has drawn public interest because some people report using it for opioid withdrawal, pain and other conditions. NIH is now taking one chemical component from that complicated plant mixture and putting it through a controlled early human study.
A purified kratom isolate enters the clinic
With the IND in effect, NIH can begin work on a first-in-humans safety study of a purified kratom isolate. The formulation was developed by researchers at NIH and the University of Florida. Their preclinical work supported the IND submission.
An Investigational New Drug application is a key regulatory step in U.S. drug development. It allows an experimental compound to be tested in humans under defined research conditions. For mitragynine, that means investigators can now move from laboratory and animal work into a carefully monitored clinical setting.
The planned trial is NIH-led and designed as a phase I clinical trial. Phase I studies usually begin with safety questions. Researchers look at how people tolerate the compound and whether early dosing raises concerns that would stop development.
Nora Volkow, M.D., director of NIH’s National Institute on Drug Abuse, framed the milestone around the urgent need for more options. “This IND is a major step toward expanding treatment options for the millions of Americans struggling with opioid use disorder,” she said.
Why mitragynine drew NIH attention
Mitragynine has attracted attention because it interacts with opioid receptors, the same broad biological signaling system involved in opioid drugs. Kratom contains many compounds that can act in the body. NIH’s announcement points to mitragynine as a likely driver of some of the plant’s reported therapeutic effects.
In the body, mitragynine appears to undergo slow conversion into related active chemicals. That gradual processing may help explain why scientists are interested in studying the purified compound on its own. A controlled formulation lets researchers ask clearer questions than they could with whole-plant products that vary in strength and composition.
Interest in kratom has grown in recent years among people seeking relief from opioid withdrawal or pain. Those real-world reports have raised scientific questions, especially because products sold to consumers can differ widely. NIH’s approach isolates one major compound and studies it using the same clinical pathway used for other experimental drugs.
The focus on opioid use disorder also reflects a continuing public health crisis. Existing medications can help many people, yet barriers, stigma, relapse risk and individual differences still leave gaps in care. A new candidate has to earn its place through safety studies first, then larger trials that test whether it helps patients.
From animal studies to human safety
Preclinical studies led by scientists at the University of Florida, NIH’s National Center for Advancing Translational Sciences and NIDA found that mitragynine administration across several doses did not raise significant safety concerns in animal models. That result supported the move toward human testing.
Animal findings are an early signal. They help researchers choose dosing ranges, watch for warning signs and decide whether a compound is ready for tightly supervised human study. They can’t answer whether mitragynine will be safe across broader patient groups or effective for opioid use disorder.
The human study will be the next major filter. The compound in isolation still lacks human safety data. A purified drug formulation also differs from consumer kratom products, which may contain many alkaloids and other substances.
Joni Rutter, Ph.D., director of NIH’s National Center for Advancing Translational Sciences, described the transition from the lab to the clinic directly. “We’ve seen the potential of mitragynine in the lab and now we’re finally able to examine its potential in people.”
That shift is important because controlled human research can separate promising biology from uncertainty. It can reveal side effects, tolerability limits and practical questions about dosing that laboratory models cannot fully settle.
What the phase I trial will test
NIH scientists are planning the first randomized, double-blind, placebo-controlled study to assess the safety and tolerability of the mitragynine formulation in humans. In a randomized trial, participants are assigned to different study groups by chance. That design helps reduce bias.
A double-blind design means participants and researchers involved in assessing outcomes do not know who receives the active formulation or placebo during the blinded portion of the study. A placebo-controlled study gives investigators a comparison group. Together, those features make early signals easier to interpret.
The trial’s main purpose is safety and tolerability. Researchers will likely monitor how the body responds, how participants feel and whether side effects appear. The NIH announcement identifies the study as a phase I effort, so it should be viewed as the beginning of human evaluation.
For readers following potential addiction treatments, the distinction is crucial. A phase I trial can move a compound forward or reveal problems early. Larger and later studies would be needed to test whether mitragynine reduces opioid withdrawal symptoms, cravings, relapse risk, or other clinical outcomes.
The purified formulation gives NIH a more precise research tool. It lets investigators study a defined dose of one compound rather than a variable plant product. That precision is central to modern drug development.
How HEAL fits into the opioid crisis
The trial is part of the Helping to End Addiction Long-term Initiative, known as the NIH HEAL Initiative. The program supports research on pain, addiction, overdose prevention and new treatment strategies tied to the opioid crisis.
HEAL’s involvement places mitragynine within a broader federal research effort. The initiative aims to move promising ideas through scientific testing, from basic biology to clinical studies. Mitragynine is one candidate in a larger search for better tools.
The need remains large. Opioid use disorder has contributed to historically high overdose mortality rates, according to NIH’s announcement. Any new therapy would need to show benefits in rigorous trials and fit safely into existing care.
For now, the advance is specific and meaningful. NIH has cleared the regulatory path for a first human safety test of purified mitragynine. The study will begin answering whether this kratom-derived compound can be evaluated safely in people.
If the early trial supports further development, the next questions will become more demanding. Researchers will need to study dose, patient selection, side effects, drug interactions and clinical benefit. Each step will help determine whether mitragynine can move from an intriguing laboratory candidate to a tested option for people with opioid use disorder.
