Desomorphine by street name Krokodil is a semi-synthetic opioid commercialized by Roche, with powerful, fast-acting effects, such as sedation and analgesia. It was first discovered and patented by a German team working for Knoll in 1920 but wasn’t generally recognized. It was later synthesized in 1932 by Lyndon Frederick Small. Small also successfully patented it in 1934 in the United States. Desomorphine was used in Switzerland under the brand name Permonid and was described as having a fast onset and a short duration of action, with relatively little nausea compared to equivalent doses of morphine. Dose-by-dose it is eight to ten times more potent than morphine.

Desomorphine is a morphine analog where the 6-hydroxyl group and the 7,8 double bonds have been reduced. The traditional synthesis of desomorphine starts from α-chlorocodide, which is itself obtained by treating thionyl chloride with codeine or prescription opioid pain medicines such as OxyContin and Vicodin. By catalytic reduction, α-chlorocodide gives dihydrodesoxycodeine, which yields desomorphine on demethylation.



Desomorphine was previously used in Switzerland and Russia for the treatment of severe pain; although for many years up to 1981, when its use was terminated, it was being used to treat a single person in Bern, Switzerland with a rare illness.[13][failed verification] While desomorphine was found to be faster-acting and more effective than morphine for the rapid relief of severe pain, its shorter duration of action and the relatively more severe respiratory depression produced at equianalgesic doses, as well as a high incidence of other side effects such as hypotension and urinary retention, were felt to outweigh any potential advantages


Desomorphine abuse in Russia attracted international attention in 2010 due to an increase in clandestine production, presumably due to its relatively simple synthesis from codeine available over the counter. Abuse of homemade desomorphine was first reported in Siberia in 2003 when Russia started a major crackdown on heroin production and trafficking but has since spread throughout Russia and the neighboring former Soviet republics.

The drug can be made from codeine and iodine derived from over-the-counter medications and red phosphorus from match strikers, in a process similar to the manufacturing of methamphetamine from pseudoephedrine. Like methamphetamine, desomorphine made this way is often contaminated with various agents. The street name in Russia for homemade desomorphine is krokodil (Russian: крокодил, crocodile), possibly related to the chemical name of the precursor α-chlorocodide, or the resemblance of the skin damage caused by the drug to a crocodile’s leather. Due to difficulties in procuring heroin, combined with easy and cheap access to over-the-counter pharmacy products containing codeine in Russia, the use of krokodil increased until 2012. In 2012 the Russian federal government introduced new restrictions for the sale of codeine-containing medications. This policy changes likely diminished but did not extinguish krokodil use in Russia. It has been estimated that around 100,000 people use krokodil in Russia and around 20,000 in Ukraine. One death in Poland in December 2011 was also believed to have been caused by krokodil use, and its use has been confirmed among Russian expatriate communities in a number of other European countries. In 2013 two cases of Krokodil use were reported in the USA. A single case of desomorphine use was reported in Spain in 2014, with the drug consumed orally rather than by injection. In 2019, there was a case of desomorphine abuse in the UK with a 41-year-old shoplifter and drug addict becoming victim to severe skin damage as a result of abusing ‘krokodil’.

Adverse effects


Toxicity of desomorphine

Animal studies comparing pure desomorphine to morphine showed it to have increased toxicity, more potent relief of pain, higher levels of sedation, decreased respiration, and increased digestive activity.

Toxicity of “krokodil”

Illicitly produced desomorphine is typically far from pure and often contains large amounts of toxic substances and contaminants as a result of being “cooked” and used without any significant effort to remove the byproducts and leftovers from synthesis. Injecting any such mixture can cause serious damage to the skin, blood vessels, bone and muscles, sometimes requiring limb amputation in long-term users.

Causes of this damage are from iodine, phosphorus and other toxic substances that are present after synthesis. Addicts often use readily available but relatively toxic and impure solvents such as battery acid, gasoline or paint thinner during the reaction scheme, without adequately removing them afterwards before injection. Strong acids and bases such as hydrochloric acid and sodium hydroxide are also employed without measuring pH of the final solution and analysis of leftover solutions of “krokodil” in used syringes showed the pH was typically less than 3 (i.e. as acidic as lemon juice). Failure to remove insoluble fillers and binding aids from the codeine tablets used as starting material, as well as co-administration with pharmaceuticals such as tropicamide and tianeptine, are also cited as possible contributors to the high toxicity observed in users.

The frequent occurrence of tissue damage and infection among illicit users are what gained the drug its nickname of the flesh-eating drug, or the zombie drug as homemade versions made under inadequate conditions contain multiple impurities and toxic substances that lead to severe tissue damage and subsequent infection as a direct consequence of use. Gangrene, phlebitis, thrombosis (blood clots), pneumonia, meningitis, septicaemia (blood infection), osteomyelitis (bone infection), liver and kidney damage, brain damage, and HIV/AIDS are common serious adverse health effects observed among users of krokodil. Sometimes, the user will miss the vein when injecting the desomorphine, creating an abscess and causing death of the flesh surrounding the entry-point.