Here is a related report from the CDC: http://www.cdc.gov/mmwr/preview/mmwrhtml/mm5849a3.htm http://www.cdc.gov/mmwr/preview/mmwrhtml/mm5849a3.htm First, I th

Here is a related report from the CDC: http://www.cdc.gov/mmwr/preview/mmwrhtml/mm5849a3.htm http://www.cdc.gov/mmwr/preview/mmwrhtml/mm5849a3.htm First, I think it is too easy to write off the Columbians not cutting the cocaine themselves. It used to be that the drugs were imported in as pure a form as possible, to reduce the weight and volume that needs to be smuggled. But what has changed today is that the Columbians no longer control the entire supply chain. Mexicans pick up the coke from Columbia and transport it themselves across the border. In the 70s through to the 90s, Escobar, Ochoa and Lehder controlled everything from production to distribution in the USA (usually with Americans they hired - such as George Jung and the guys featured in Cocaine Cowboys). Today the Mexican cartels control all the smuggling and distribution in the USA - so it actually makes sense that the Columbians are cutting their product in order to increase profits. I read up on Levamisole to get more information about it (its melting point is 30% higher than coke - molecular mass of a third more) . I was looking into this speculating that the reason it is used as a cutting agent could be because it isn't picked up in purity tests that the cartels use. For some reason the CDC and DEA are finding it (perhaps because they explicitly test for it) while the Mexican cartels are not. It is also suitable to use as a cutting agent since it is metabolized into a compound that has similar effects to amphetamines (which have also been used to cut coke with previously). The article suggests this, as there is currently no easy test kit for Levamisole. Second part I would speculate on is that Levamisole is somehow finding its way into the production process unintentionally. It could be that livestock in Columbia is treated with the drug (de-worming etc.) and that the labs are contaminated because of the fertilizer used, or because of some other part of the process. Nowhere online does it mention the quantities of Levamisole found in the cocaine, which makes it difficult to speculate on the source. If it was one part per thousand, you could narrow it down to contamination or impurities passing through, if it was 1 part in 5, you could argue that it is a cutting agent.