Around the Tampa Bay region, consumers can walk into smoke shops and gas stations and buy a substance that experts say mimics a powerful opioid.
No prescription is required. The products are virtually unregulated: Bills to curb their sale have repeatedly died in Tallahassee. State and federal regulators have done almost nothing to intervene.
Scientists say the substance, called 7-hydroxymitragynine or 7-OH, poses a public health threat.
7-Hydroxymitragynine (7-OH) is a terpenoid indole alkaloid from the plant Mitragyna speciosa, commonly known as kratom.[2] It was first described in 1994[3] and is a human metabolite metabolized from mitragynine present in the Mitragyna speciosa. 7-OH binds to opioid receptors like mitragynine, but research suggests that 7-OH binds with greater efficacy.[4]
7-Hydroxymitragynine (7-OH), a metabolite of the psychoactive botanical kratom, exhibits significantly higher binding affinity to mu-opioid receptors (MOR) than morphine, with estimates ranging from 14 to 22 times greater potency. Although kratom’s primary alkaloid, mitragynine, is associated with lower abuse potential and moderate safety, 7-OH demonstrates opioid-like effects and can substitute for morphine in a dose-dependent manner, raising concerns about its potential for physical dependence and addiction.[5]
Pharmacology
7-Hydroxymitragynine, like mitragynine, appears to be a mixed opioid receptor agonist/antagonist, with recent research indicating that it acts as a partial agonist at μ-opioid receptors and as a competitive antagonist at δ- and κ-opioid receptors.[6][7] 7-OH does not appear to activate the β-arrestin pathway, distinguishing it from traditional opiate & opioid chemicals.[6] It shares this trait with mitragynine.
Synthesis
In natural kratom leaves, 7-Hydroxymitragynine is only present in extremely small amounts (around 0.01% to 0.04% of total alkaloid content). Therefore, extracting 7-OH in high concentrations directly from natural kratom leave is not feasible due to the natural yield being too low. This means that all high-concentration 7-OH products must be produced via chemical synthesis rather than simple extraction. The most common methods usually involve chemically modifying mitragynine, the most abundant alkaloid in kratom, to artificially increase 7-OH concentration via oxidation reactions. This process often involves the usage of reagents such as hydrogen peroxide, enzymes, or strong acids to convert the mitragynine into 7-OH.