VIENNA, Austria – 29 August 2025: Since 2024, novel kratom-related products have emerged on consumer markets, particularly in the United States. These products often contain high concentrations of 7-hydroxymitragynine and/or mitragynine pseudoindoxyl.^1,2 Laboratory and surveillance methods need to adapt to monitor these more potent compounds.

The alkaloid 7-hydroxymitragynine (7-OH) is a naturally occurring substance in the kratom plant (Mitragyna speciosa), but only as a minor constituent (formed during the drying process) compared with mitragynine. 7-hydroxymitragynine is also a metabolite of mitragynine, and is further metabolized to mitragynine pseudoindoxyl.²

Notably, 7-hydroxymitragynine and mitragynine pseudoindoxyl demonstrate substantially greater mu-opioid receptor potency than mitragynine. The risk of overdose is high, as 7-hydroxymitragynine may be more potent than morphine at causing respiratory depression.^1,3 Other health concerns include physical dependence and withdrawal symptoms similar to those caused by classical opioids.³

Recent testing of six novel kratom-related products marketed as “7-hydroxymitragynine” revealed that 7-hydroxymitragynine was contained in all samples together with mitragynine pseudoindoxyl, mitragynine and paynantheine in varying concentrations¹ (see photo 1). According to Hill and others, these novel "7-OH" products are likely synthesized in laboratories from purified mitragynine.²

 
Photo 1: Examples of “7-hydroxymitragynine” marketed products and their lab results
Note: Parts designation is described by Krotulski and others as follows: “p” = parts. 0.5p = half as abundant as 1p. 2p = 2x more abundant than 1p.¹
Source: Krotulski and others.¹

The growing number of semi-synthetic kratom-related products are found in diverse forms including chewable/sublingual tablets or strips, gummies, drink mixes, shots, syrups, vape pens, capsules, food products or powders.² The marketing strategies and easy accessibility of these products raise significant health concerns, as these products may not be clearly or accurately labelled², might be designed to appeal to young people (see photo 2) and are available in corner stores, gas stations and vape shops in the United States.^4,5 Moreover, “7-hydroxymitragynine” marketed products are also available on websites outside of the United States.^*



Photo 2: Forms and design of new kratom-related (7-hydroxmitragynine) products
Source: United States, Food and Drug Administration.⁶ 

Hill and others compiled a database with more than 304 7-hydroxymitragynine and mitragynine pseudoindoxyl marketed products (not chemically verified). Most products claimed to be “kratom-based” and suggested effects such as “general wellbeing”, “pain relief” or “stress/anxiety reduction”, misleading consumers who intend to use a “low-potency botanical supplement” but instead end up with an opioid-like NPS.²

So far, since 2024, the United States and Australia have reported toxicology cases with high concentration 7-hydroxymitragynine products being involved to the UNODC Early Warning Advisory (EWA) on New Psychoactive Substances Tox-Portal (data collection is ongoing).⁷

Kratom, mitragynine, 7-hydroxymitragynine and mitragynine pseudoindoxyl are currently not controlled under the UN conventions⁸. In the United States, kratom and its constituents are not nationally controlled.³ The United States Food and Drug Administration (FDA) state in their 7-OH assessment that “none of these substances are lawful when added to conventional foods, as dietary supplements, or as ingredients in any FDA-approved drug”.³ In July 2025, FDA recommended a scheduling action to control certain 7-hydroxymitragynine products under the Controlled Substances Act.⁴ Some countries control kratom and/or mitragynine (e.g. Australia, Slovakia), whilst others have specifically additionally controlled 7-hydroxymitragynine and/or other kratom alkaloids (e.g. France, Luxembourg, Singapore).


Response options

- Raise awareness among:
   + health care providers (e.g. see FDA letter for health care professionals; Pennsylvania Department of Health alert),
   + law enforcement,
   + regulators (consider potential gaps in existing legislation),
   + people who use drugs and/or the public, if locally relevant (e.g. see FDA educational material⁶)

- Ensure access to lifesaving treatments such as naloxone³

- Provide comprehensive drug dependence treatment and care programmes as important components of overdose prevention

- Enhance capabilities of forensic drug testing and toxicology laboratories - reference standards and appropriate analytical methods are needed to effectively identify and differentiate mitragynine-related compounds. Complexities such as metabolism³, poor stability especially in biological samples^1,9 and limitations of some standard methods such as GC-MS need to be considered.¹

- Include 7-hydroxymitragynine and mitragynine pseudoindoxyl in data collections for early warning systems, drug observatories and (self-reported) drug use surveys.³ UNODC EWA has responded already by creating NPS entries and analytical findings are encouraged to be shared.
* Results of a Google search using “7-OH”, “buy”, “comprar”, “kaufen” and/or the respective country name.
***We would like to acknowledge the contributions from the United States Drug Enforcement Administration and the Emerging Drugs Network of Australia to the UNODC EWA Tox-Portal.

References:

1. Alex J. Krotulski and others, "Evaluation of Commercially Available Smoke Shop Products Marketed as “7-Hydroxy Mitragynine” & Related Alkaloids", Center for Forensic Science Research and Education, Test Purchase (March 2025). Available at: https:// cfsre.org/images/content/reports/public_alerts/7-Hydroxy_Mitragynine_NPS_Discovery_033125.pdf (accessed on 10 August 2025).
2. Katherine Hill and others, "De facto opioids: Characterization of novel 7-hydroxymitragynine and mitragynine pseudoindoxyl product marketing", Drug and Alcohol Dependence, vol. 272 (2025).
3. United States, Food and Drug Administration, "7-Hydroxymitragynine (7-OH): An Assessment of the Scientific Data and Toxicological Concerns Around an Emerging Opioid Threat", 2025. Available at: https://fda.gov/media/187899/download (accessed on 10 August 2025).
4. United States, Food and Drug Administration, "FDA Takes Steps to Restrict 7-OH Opioid Products Threatening American Consumers", FDA news release, 29 July 2025. Available at: https://fda.gov/news-events/press-announcements/fda-takes-steps-restrict-7-oh-opioid-products-threatening-american-consumers#:~:text=The%20U.S.%20Food%20and%20Drug,Controlled%20Substances%20Act%20(CSA) (accessed on 10 August 2025).
5. United States, Drug Enforcement Administration (DEA), "Kratom (Mitragyna speciosa korth)", April 2025. Available at: https://deadiversion.usdoj.gov/drug_chem_info/kratom.pdf (accessed on 10 August 2025).
6. United States, Drug Enforcement Administration, “Preventing the next wave on the opiod epidemic: What you need to know about 7-OH”, n.d. Available at: https://www.fda.gov/media/187900/download (accessed on 10 August 2025).
7. United Nations, UNODC Early Warning Advisory on New Psychoactive Substances (EWA) Tox-Portal, Database (accessed on 10 August 2025).
8. World Health Organization, “WHO Expert Committee on Drug Dependence - Forty-fourth report”, WHO Technical Report Series, No. 1038 (2022).
9. Kei A. Osawa and Robert D. Johnson, "Postmortem distribution of mitragynine and 7-hydroxymitragynine in 51 cases", Journal of Analytical Toxicology, vol. 49 (2025), pp. 122–128.