"Xylazine is a non-opiate sedative, analgesic, and muscle relaxant that shares its drug class (α2-adrenoreceptor agonists) with medications such as clonidine, lofexidine, tizanidine, and dexmedetomidine [6].

"Prior to the widespread availability of xylazine in the Philadelphia drug supply, it was often mentioned in passing by residents of the majority Puerto Rican neighborhood where our fieldwork was based as a powerfully psychoactive additive ‘“back on the Island”.’ Xylazine was occasionally detected in fatal overdoses in Philadelphia as early as 2006 (Wong et al., 2008), but it was not common knowledge among PWID.

"At least a decade after Xylazine became a fixture in Puerto Rico, it entered the street opioid supply in Philadelphia as a more prevalent additive in the mid-2010s. The shift was noted by PWID, as well as harm reductionists and city public health officials (Johnson et al., 2021). PWID began to describe xylazine – often referred to as tranq – as a known element of specific ‘stamps’ or brands of opioid products in the illicit retail market.

"Xylazine is a veterinary tranquilizer, which is not approved for human use in the United States, but is commonly used for sedating large animals (Reyes et al., 2012; Ruiz-Colón et al., 2014).

"Xylazine, also called “tranq” or “tranq dope,” is a non-opioid veterinary tranquilizer. Although not approved by the United States (US) Food and Drug Administration for human use, xylazine is increasingly being identified as an adulterant in illicitly manufactured fentanyl and heroin, and occasionally in other drugs such as cocaine and methamphetamine in the US [1, 2].

"Fentanyl test strips (FTS) emerged in this context as a drug checking tool to address the burgeoning fentanyl crisis. FTS was originally developed as a field immunoassay to screen for the presence of fentanyl in urine, but harm reduction organizations discovered that FTS can also detect fentanyl in illicit drug solutions.

"Within Canada, there are various prescribed safer supply models each with the goal of reducing unregulated opioid overdose without requiring cessation of substances. While some programs offer non-opioid safer supply options including stimulants and benzodiazepines, the primary focus remains opioids.

"Two things are needed to move beyond policy-biased appraisals of the evidence on cannabis and psychosis.

"The 2021 review of cannabis policy found that states also have limits on ingredients that can be contained in cannabis products. Many states have banned or are testing for vitamin E acetate because of the 2019 outbreak of e-cigarette or vaping product–associated lung injury (EVALI) (Schauer, 2021). Colorado has banned medium-chain triglycerides oil and polyethylene glycol oil entirely. Similarly, Oregon has prohibited squalane, propylene glycol, and all triglycerides, substances that lack established safety data for aerosols.

"Based on NSDUH estimates, rates of cannabis abuse and dependence remained relatively stable from 2002 to 2019, with the highest rates of abuse and dependence among young adults (aged 18–25) (Figure 3-27). For 2020, except for youth (aged 12–17), for whom the data suggest a slight decline in rates of cannabis abuse and dependence, the data are generally consistent with the longer-term trends for the other age groups. In 2021, the NSDUH introduced the diagnostic category of cannabis use disorder to better accord with DSM-V criteria for classifying substance use disorders.