Buy Etonitazene ( EA-4941) Cas 911-65-9

Etonitazene, also known as EA-4941 or CS-4640,^[2] is a benzimidazole opioid, first reported in 1957,^[3] that has been shown to have approximately 1,000 to 1,500 times the potency of morphine in animals.^{[4][better source needed]}

Because it is characterized by a strong dependency potential and a tendency to produce profound respiratory depression, it is not used in humans. It is, however, useful in animal models for addiction studies, particularly those requiring the animals to drink or ingest the agent, because it is not as bitter as opiate salts like morphine sulfate.^{[citation needed]}

Etonitazene is one of just two nitazenes that was banned in the UK since 1971, the other being clonitazene, as these were included in UN conventions.

Nitazenes were not seen in the UK drug market until they began to appear in heroin in the early 2020s. In 2024 Etonitazene was moved to Schedule 1 alongside 14 other nitazenes being added to the UK Misuse of Drugs Act.^[5]

A number of analogues are known, with the only other well-known compound to come out of the original 1950s research being clonitazene, which is much weaker than etonitazene (around 3x morphine). More recently since around late 2018 a number of designer analogues have started to appear on illicit markets around the world, with the most prominent compounds being metonitazene, isotonitazene and etazene, though others have continued to appear.^[6][7]

Of these analogues, only etonitazene and clonitazene are explicitly listed under UN conventions and so are controlled throughout the world. The rest would only be illegal in countries such as the US, Australia and New Zealand that have laws equivalent to the Federal Analog Act. In the United States Etonitazene is a Schedule I narcotic controlled substance with a DEA ACSCN of 9624 and a 25 gram (7⁄8 oz) manufacturing quota as of 2022.