Semi-synthetic products based on 7-hydroxymitragynine: a public health emergency

Over the last twenty-four months, the market for substances derived from Mitragyna speciosa (Kratom) has undergone a qualitative shift: alongside traditional leaf and crude extracts, semi-synthetic concentrated products based on 7-hydroxymitragynine (7-OH) have emerged, obtained through controlled oxidation of mitragynine and formulated as sublingual tablets, gummies, vaping devices, nasal sprays and edibles. These products, which can reach 98% 7-OH content as a single active ingredient, fall outside the botanical pharmacopoeia of kratom and de facto constitute a new class of semi-synthetic u-opioid agonists with potency comparable to, or exceeding, that of morphine. This position paper summarises the available pharmacological, neurobiological, toxicological and medico-legal evidence, with specific reference to the Italian legal context, and sets out operational recommendations for forensic pathologists, forensic toxicologists, medico-legal experts and technical consultants called upon to intervene in cases of suspected intoxication, death, occupational accident or criminal offence linked to the use of such products. The paper addresses: (a) the methodological problem of using mitragynine as a surrogate marker of kratom exposure in the presence of 7-OH-enriched products; (b) the post-mortem instability of 7-OH and its interpretive implications for causality assessment; (c) the evaluation of criminal responsibility (capacity to understand and to will) in chronic users; (d) the need to update the analytical panels of Italian toxicology laboratories.