Nonswallowed Kratom-Derived Products: Unlawful Dietary Supplements That Endanger Public Health

Abstract

The Dietary Supplement Health and Education Act of 1994 specified that dietary supplements must be swallowed. In this study, we investigated whether kratom-derived products are being sold to consumers in nonswallowed formulations. Kratom is the fresh or dried leaf powder of the Mitragyna speciosa tree. We identified 49 kratom-derived products being sold in the form of sublingual strips (24%), buccal pouches (8%), and vaping products (67%). Most contained 7-hydroxymitragynine (an alkaloid that the US Food and Drug Administration seeks to make a controlled substance), but we also identified mitragynine extract and mitragynine pseudoindoxyl products. The majority had flavoring or a scent, and some had mascots, pictures of fruit or mint, or formulation colors or packaging that could appeal to children. Most products were not sold in child-resistant packaging. Several kratom vaping products additionally contained intoxicating hemp cannabinoids. With no clinical, safety, or pharmacokinetic data for kratom-derived products that bypass first-pass metabolism (ie, where a chemical absorbed through the stomach or intestines is metabolized in the liver before reaching the general bloodstream), people should be advised to avoid these products, and regulatory action is needed to prevent their sale to consumers.

Whole-leaf kratom is the fresh or dried leaf powder of the Mitragyna speciosa tree and contains inert cellular components from the leaves with many biologically active alkaloids that stimulate serotonin, α-adrenoceptor, and opioid receptors.^1,2 The most abundant alkaloid in whole-leaf kratom is mitragynine. ¹ While whole-leaf kratom has not been approved by the US Food and Drug Administration (FDA) as a new dietary ingredient, the US Drug Enforcement Agency (DEA) decided not to make it a controlled substance in 2016 and 2018. ² The FDA assessed reports of kratom-related adverse events and recently conducted a preliminary tolerability study of whole-leaf kratom without concerning findings, but it has not made a final determination about dietary supplement designation. ³

Unfortunately, kratom-derived products are moving toward higher-potency mitragynine extracts, semisynthetically created 7-hydroxymitragynine (7-OH), or mitragynine pseudoindoxyl alkaloids.^2,4 Oral versions of these kratom-derived products are increasingly fruit flavored, brightly colored, and candy formulated and have names that harken illicit opioid use (eg, Perks, Roxy, Opia, Ch7ll P7ll, Float).^1,5 They are sold through gas stations, convenience stores, smoke shops, and the internet.

Manufacturers state that they can lawfully sell kratom-derived products because they are not scheduled substances under federal law, but in July 2025, the FDA advocated for 7-OH products to be designated as controlled substances by the DEA. ⁶ The FDA cites the potency of μ-opioid receptor stimulation, the potential for rapid tolerance and use disorder, and the respiratory depression potential of 7-OH. ⁶ Additionally, the products feature isolated and concentrated 7-OH, which is chemically created from mitragynine and not extracted from leaf kratom. ⁶ However, the Dietary Supplement Health and Education Act (DSHEA) of 1994 was clear that dietary supplement products must be formulated to only be swallowed^7,8 because products that bypass first-pass metabolism (ie, where a chemical absorbed through the stomach or intestines is metabolized in the liver before reaching the general bloodstream) may boost bioavailability, speed the onset of action, and allow harmful chemicals to pass into the blood. ⁹ As such, the FDA has the authority to send warning letters to all manufacturers and distributors of whole-leaf kratom or kratom-derived products and start enforcement actions if such products are formulated to not be swallowed. ⁷

Methods

In this study, we investigated whether kratom products are being made in nonswallowed formulations in violation of DSHEA 1994—that is, as injected, inhaled, insufflated (commonly called “snorting”), sublingual, lingual, or buccal (placed against the cheek to be absorbed directly into bloodstream). We also examined the characteristics of those products to alert clinicians and the FDA.

We performed a systematic search via the Google search engine from January 5 through February 15, 2025, using a priori search terms: “buy” with “kratom,” “mitragynine,” “7-hydroxymitragynine,” “7-OH,” “mitragynine pseudoindoxyl,” or “Red-OH” (a pseudonym of mitragynine pseudoindoxyl) and then with “sublingual,” “buccal,” “injected,” “subcutaneous,” “intramuscular,” “intravenous,” “inhaled,” “vaped,” “e-liquid,” or “intranasal.” The Google search engine has >90% of the internet search traffic in the United States. ¹⁰

Ethical Considerations

This project collected publicly available data from product websites and was determined to be exempt from review by the University of Connecticut Institutional Review Board because it did not involve patients, consumers, students, or their data.

Results

We identified 49 kratom-derived products that were formulated to not be swallowed: 12 (24%) sublingual strips, 4 (8%) buccal pouches, and 33 (67%) vaping products that contained kratom-derived ingredients across 15 online retailers (eTable 1 in the Supplement). We did not find any whole-leaf kratom products with formulations that were not to be swallowed. We also did not find any products for the other prespecified routes of administration. While most online retailers required shoppers to click a button stating that they were at least 21 years of age to enter or to provide a birth date, they did not verify the age of the shopper to access the site or when the shopper sought to purchase the product (ie, vis-à-vis one’s birth date). All product-specific information collated in the following sections is detailed in eTables 2 to 4 in the Supplement.

Sublingual or Buccal Product Characteristics

Of the 16 sublingual or buccal products, 10 contained 7-OH as the stated active ingredient, 5 mitragynine, and 1 mitragynine pseudoindoxyl.

Eleven products had sublingual strips in what appeared to be child-resistant foil packaging. The 4 buccal products were clearly not in child-resistant packaging, and for 1 sublingual product, we could not determine whether the packaging was child resistant. However, 4 of the 11 sublingual products had a serving size of one-quarter or one-half strip, leaving the remaining strip accessible to children without protective packaging. As such, only 7 of 16 sublingual or buccal products were packaged to be child resistant.

Fourteen products had flavoring or scents, 4 had a mascot, 4 featured images of food, and 4 had formulations that were brightly colored and could appeal to children. Aside from 1 product for which no image of the packaging was available, all other product packaging was brightly colored and would appeal to children. Some of the product names that would appeal to children included Rave, Sonic Boom, and K-Dips.

Inhaled/Vaping Product Characteristics

Of the 33 vaping products, 29 (88%) came with a vaping pen and e-liquid, and 4 (12%) were replacement vaping e-liquids. Sixteen products (48%) contained 7-OH alone, and 5 (15%) had 7-OH and an intoxicating hemp ingredient (called a proprietary hemp blend). As such, 21 of the 33 products (64%) had 7-OH as the predominant kratom alkaloid. Twelve products (36%) specified that they were kratom derived, but whether they contained an extraction or semisynthetic alkaloid was unclear; furthermore, 3 of the 12 products included an intoxicating hemp ingredient called hexahydrocannabinoid. As such, 8 of the 33 products (24%) had an added intoxicating hemp ingredient.

We were unable to determine whether the vaping products were in child-resistant packaging upon purchase. However, once the vaping products were opened, the residual vaping liquid would be accessible for inadvertent or intentional inhalation or ingestion by children, so we classified all products as not child resistant.

Of the 33 products, 24 (86%) were scented or flavored with fruit or mint, 12 (43%) had pictures of fruit or mint on the packaging, and none had a mascot. Aside from 1 product for which no image of the packaging was available, all other packaging was brightly colored and would appeal to children. Some of the product names that would appeal to children included Tropical Zkittles, Bubbilicious, Blue Razz Ice, and Red Berry Love.

Discussion

Although nonswallowed dietary supplements are not allowable under DSHEA 1994, we found numerous sublingual, buccal, and inhaled products being sold to consumers. Many products had features that would attract children, but most did not have child-resistant packaging. Some products combined kratom-derived alkaloids with cannabinoids. The most common alkaloid in these products was 7-OH, which the FDA is asking the DEA to classify as a controlled substance. ⁶ However, doing so would not prevent consumers from substituting newly banned products for other nonswallowed products that contain other alkaloids.

To our knowledge, this is the first study to identify, categorize, and catalogue nonswallowed kratom-derived products. Previous studies have reported on oral kratom-derived products and their characteristics. Like the nonswallowed products that we identified, the liquid and oral tablet products previously examined frequently have scents and flavorings that would appeal to children and are not in child-resistant packaging.^1,5 The FDA should immediately send warning letters to the makers or distributors of these kratom-derived products with nonswallowed formulations because they violate DSHEA 1994. ⁷ While these products are not officially designated as dietary supplements, they are all being sold under the premise that they are unapproved new dietary ingredients; therefore, their manufacturers should abide by the regulations forbidding the use of these formulations.^1-3,7 To hasten regulatory action, we clearly identified the products and their sellers (Supplement).

If patients are taking formulations of kratom-derived products that are not swallowed, clinicians should convey important information about their risks. First, no clinical trials have assessed the safety or efficacy of any kratom-derived products in healthy volunteers or patients.^1,2,4 Second, no pharmacokinetic studies of nonswallowed kratom-derived product formulations have been conducted, so the effects experienced by a person using a swallowed product may differ from the effects of a nonswallowed formulation. ⁹ Oral administration of a mitragynine extract resulted in a time to peak blood concentration of 1.5 hours and an estimated bioavailability of 21%. ¹¹ Bypassing first-pass metabolism through sublingual, buccal, or lung absorption could substantially boost this low bioavailability. ¹¹ Third, because all of these kratom-derived products have opioid receptor stimulation associated with their mechanism of action, clinicians should discuss with patients the potential risks of tolerance, addiction, withdrawal, and respiratory depression.^1,2,4 Fourth, most of these products are not sold in child-resistant packaging, despite most having features attractive to children such that they try them, whether inadvertently or intentionally.

This study had 2 limitations. First, if we had used additional search engines, broadened the time frame of the search, and physically went to stores, we could have identified more products. Second, if we had purchased the products, rather than relying solely on information from their websites, we might have been able to characterize them further.

With no clinical, safety, or pharmacokinetic data for nonswallowed kratom-derived products, people should be advised to avoid them, and regulatory action is needed to prevent their sale to consumers.