SABER Statement on FDA-Sponsored Pilot Study on Botanical Kratom Published in the Journal of Clinical Psychopharmacology

The Scientific Association for Botanical Education and Research (SABER) today acknowledges the publication of a U.S. Food and Drug Administration (FDA)-sponsored clinical study evaluating the pharmacokinetics, pharmacodynamics, and safety of a natural kratom leaf product. This is a landmark publication in the Journal of Clinical Psychopharmacology of the first controlled clinical trial on the botanical kratom conducted by the FDA itself.

This randomized, double-blind, placebo-controlled, single ascending-dose study evaluated oral doses of the botanical kratom ranging from 1 g to 12 g in healthy adult participants with prior opioid experience. Safety assessments included adverse event monitoring, lab tests, vital signs, ECGs, physical exams, and suicidality screening.  Most importantly, the kratom material used in the study was extensively characterized and determined to be representative of traditional botanical leaf, containing only naturally occurring alkaloids with trace levels of 7-hydroxymitragynine (7-OH).

Key findings:

• No serious adverse events or deaths were reported at any dose level, supporting a favorable acute safety profile under controlled conditions.
• The most commonly reported side effect was nausea, which appeared at the higher doses — though it should be noted that consuming 8–12 g in five minutes is atypical for consumers.
• Observed effects were generally dose-related and consistent with prior observational data.
• Dose-dependent pharmacokinetics were observed for mitragynine and other alkaloids, with measurable plasma concentrations increasing predictably with dose.

“This study is an important step forward in bringing controlled human data into a conversation that has long been dominated by anecdote and preclinical findings,” said Dr. Mary Hardy, MD, member of SABER’s Scientific Steering Committee. “The findings reinforce that natural botanical kratom leaf at controlled doses has a manageable safety profile.”

This pilot study is the precursor to a larger Human Abuse Potential (HAP) study, which the lead investigator, FDA scientist Chad Reissig, announced began in late 2024, with results expected around the end of 2026. This also comes alongside a separate, even larger controlled kratom study by Huestis et al. (2026, Therapeutic Drug Monitoring) — a randomized, double-blind, placebo-controlled dose-escalation study in 116 healthy volunteers examining single daily doses of dried kratom leaf powder (6.65–53.2 mg mitragynine) for 15 days. That study similarly found no serious adverse events or deaths, with dizziness, nausea, and headache as the most common side effects, and notably reported no evidence of meaningful abuse potential or withdrawal.

The regulatory significance is substantial: the FDA in 2025 recommended the DEA schedule only 7-hydroxymitragynine and semi-synthetic analogues, not plain leaf kratom, as Schedule I — a notable shift from 2016 when the FDA recommended scheduling all kratom.

SABER emphasizes that these findings underscore the need for a science-based approach to regulation that clearly differentiates the natural botanical kratom products from semi-synthetic drugs, like 7-hydroxymintergynine.

“Public health policy must be evidence-based,” added Dr. Hardy. “This study supports a more nuanced approach that prioritizes consumer safety, product quality, and makes clear distinctions between traditional botanical preparations and high-risk, unapproved synthetic drug formulations.”

SABER remains committed to advancing high-quality scientific research, education, and evidence-based policy in the botanical space.

About Scientific Association for Botanical Education and Research (SABER)

The Scientific Association for Botanical Education and Research (SABER) is a nonprofit organization dedicated to the evidence-based study, science-forward regulation, and safe access to botanical compounds. Led by a Scientific Steering Committee of medical professionals and researchers, SABER utilizes research partnerships, policy advocacy, and public education to ensure that natural products are studied responsibly and regulated appropriately. To learn more, visit www.saberscience.org.

Media Contact

Paloma Lehfeldt
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