Randomized trial examines abuse-related effects of dried kratom leaf powder

Why it matters

This randomized, placebo-controlled study provides human data on dose-related subjective effects and withdrawal measures for a standardized dried-leaf powder. Its findings apply to the tested product and doses, not necessarily to other kratom formulations.

The big picture

Clinical evidence on kratom has been limited, while products and alkaloid concentrations vary widely. The authors studied healthy, kratom-naive adults under controlled conditions and disclosed industry support and consulting relationships.

Key findings

• 116 healthy kratom-naive adults participated in a randomized, double-blind, placebo-controlled study.
• Participants received single or 15 consecutive daily doses of dried leaf powder ranging from 500 to 4,000 mg, equivalent to 6.65 to 53.2 mg mitragynine.
• Subjective Drug Effects Questionnaire responses rose with dose, with statistically significant placebo differences reported only at the highest single dose.
• Responses declined after repeated dosing, and no participant met the study threshold for clinically meaningful opioid withdrawal.
• Higher doses produced more abuse-related treatment-emergent adverse events, which were generally mild; no serious adverse events or deaths were reported.

What they say

The authors wrote that the results support further research while emphasizing “the importance of dose control and product standardization.”

Bottom line

In this controlled trial of a specific dried-leaf product, subjective effects were dose-related and withdrawal measures remained below the study threshold, but the results should not be generalized to concentrated or unregulated products.