Background Oral pouch products containing nicotine analogues such as 6-methyl nicotine (6MN) were recently introduced to evade federal and state regulations. Preclinical studies demonstrated that 6MN is more toxic than nicotine and binds to nicotinic receptors with higher potency. However, the nicotine analogue contents of oral pouch products and the associated health risks remain unknown.

Methods Twenty-five flavor varieties from three oral pouch product (OPP) brands (Aroma-King, Hippotine-Happy Hippo, MG-Upperdeckys) marketed to contain 6MN were purchased in 2024-25. 6MN was quantified by either GC-FID (Yale) or GC-MS (Duke) to assess the estimated exposure dose (EED) from OPP use. Health risks associated with acute 6MN exposure from a single pouch use were assessed by calculating (i) hazard quotient (HQ) for heart-rate increase, and (ii) margin of exposure (MOE) for convulsions, with HQ more than 1 considered a potential health risk and the acceptable safety threshold value of MOE for proconvulsive effects considered 10. For comparison, both risk measures were determined for Zyn nicotine pouch products.

Results 6MN contents in analyzed OPPs ranged from 2.96-14.5 mg and diverged significantly from labelled contents for some products. HQ’s for 6MN OPPs for heart-rate increase ranged from 74-381, compared to 95-162 for nicotine in Zyn. MOEs for convulsion risk ranged from 0.6-2.8, indicating elevated risk. MOEs for nicotine in Zyn products were 3.2-5.4

Conclusions 6MN contents in novel pouch products are higher than in popular nicotine pouch products. Consumers using these products are exposed to 6MN levels that may exceed safety thresholds, potentially leading to adverse health effects. Nicotine analogues should be urgently addressed by lawmakers and regulators, and FDA should be authorized to regulate products containing them.

Dr. Jordt provides consulting services to the Department of Justice of the State of California on matters of tobacco product regulation

This work was supported by funds from Duke University to SEJ, and funds from Yale University to JBZ.

I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained.

Yes

I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals.

Yes

I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance).

Yes

I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable.

Yes

All data produced in the present work are contained in the manuscript