Gray death

In slang, Gray death—is heroin that has been laced with synthetic opioids. Samples have been found to contain the designer drug U-47700, heroin and opioids including fentanyl and carfentanil.[1] It is taken by injection, smoking, snorting or oral ingestion.[2]

Opioid addicts are normally those who encounter and consume this drug. They may think they are buying heroin, unaware that it is actually gray death.[3]

Reversing a gray death overdose frequently requires multiple doses of naloxone, whereas a typical overdose of heroin (which is much less potent) typically needs one dose.[2] This is consistent with the difficulty of overdose reversal seen with high-affinity opioids in the fentanyl chemical family or with buprenorphine. The greater affinity of these substances for the μ opioid receptor causes less naloxone to bind to receptors, increasing the dose necessary to counteract the respiratory depression.

the difficulty in reversing an overdose of gray death is likely due to the presence of a fentanyl analogue, which reporting seems to corroborate as of December 2018. What makes gray death so dangerous is not the constituents which make up the drug itself, but instead the fact that the drugs' identities, their overall ratios in the product, and their uneven distribution within the product are completely unknown to the user.[2] This means that the user cannot predict what dose to safely take; even taking an identical dose by mass may result in more or less of an unknown substance due to uneven physical distribution as seen with heroin and fentanyl mixes.