Johns Hopkins Study Identifies 304 Semi-Synthetic 'De Facto Opioid' Products Marketed as Kratom

Why it matters

Semi-synthetic products containing 7-hydroxymitragynine (7-OH) and mitragynine pseudoindoxyl (MP) — potent mu-opioid receptor agonists not naturally present in fresh kratom leaves — are being sold openly online under the kratom brand, posing a distinct and poorly understood public health risk beyond traditional kratom leaf products.

The big picture

The rapid commercialization of semi-synthetic kratom-derived opioids represents a new frontier in the emerging drug landscape. Unlike natural kratom leaf, which contains mitragynine at partial opioid activity, 7-OH and MP are highly selective full mu-opioid agonists with potency comparable to classical opioids. These products exist in a regulatory gray zone, often labeled as 'kratom' despite being pharmacologically quite different from the leaf.

Key findings

• Researchers identified 304 products containing 7-OH and/or mitragynine pseudoindoxyl sold online between Sept 2024–Feb 2025
• 82.2% were 7-OH-only products; 14.5% combined 7-OH and MP; 3.3% were MP-only
• Products were sold as chewable tablets, gummies, shots, and sublingual preparations
• 92% of 7-OH-only products were advertised as 'kratom' despite being semi-synthetic opioids
• 73.3% made claims about effects (focus, relaxation); 37.8% claimed pain and anxiety relief; 12.5% made drug claims
• Mean cost per dose was $3.97, with MP products averaging closer to $5 per serving
• Several products had names alluding to prescription opioids

What they say

The authors, affiliated with Johns Hopkins School of Medicine, noted that 7-OH and MP are "highly selective mu opioid receptor agonists undetectable or not present in fresh kratom leaves and may, as constituents of novel product formulations, pose public health risks."

Bottom line

Hundreds of semi-synthetic opioid products — pharmacologically closer to prescription opioids than to kratom leaf — are being sold openly online under kratom branding, highlighting an urgent gap in regulatory oversight.