Coca as seen by the WHO: will the error be corrected?

The discourse surrounding the coca leaf in the 20th century has been marked by contempt, promoted directly by the World Health Organization (WHO) and other United Nations agencies. In the 1950s and 1960s, they claimed that the coca leaf was a social evil and the cause of degeneration in Andean societies, as reconstructed in the dossier presented by Bolivia for the ongoing critical review process. The draft report of the Expert Committee on Drug Dependence (ECDD) therefore comes as a vindication, concluding that the coca leaf does not pose significant risks to human health. 

However, the second conclusion is less positive, as it states that cocaine is easily extractable from the coca leaf, thus raising early concerns about the recommendations that the Committee may issue. If the aim of the critical review process is to remove the coca leaf from the control lists, or at least move it to a less restrictive list, the discussion on extractability will be key. 

The critical review process of the coca leaf has entered a crucial phase, as this report of scientific findings on the coca leaf will form the basis of the recommendations to be issued between November and December of this year and voted on in March 2026 by the CND, which will define the fate of coca in the international drug control system. This document is the result of a combination of available scientific evidence, contributions from the States Parties to the Conventions, and reports from civil society. 

Although this is a draft, given its relevance, we will analyze its content, gaps, and omissions, as well as the scenarios it presents for the reclassification process.      

1.What is the coca leaf?

The coca leaf is the main organ of the coca bush. It naturally contains alkaloids—substances that are of international concern due to drug trafficking—including ecgonine, cocaine, and other ecgonine alkaloids. In total, more than 197 alkaloids have been identified in this plant. The coca leaf is part of the Erythroxylum genus, which has more than 250 varieties. 

However, since the 1970s, two species have predominated: Erythroxylum coca and Erythroxylum novogranatense. These, in turn, have different varieties. The study explains that, although the chemical composition is similar, there are differences in the amount of compounds present in this plant. Some coca plants do not even contain cocaine. The presence and amount of alkaloids varies according to the species, and cocaine in particular is present in a range between 0.5% and 2.4%.  

2. The not-so-easy business of cocaine extraction

The relationship between coca leaves and cocaine is inseparable, as most coca species contain cocaine. However, what can be separated is the analysis of coca leaves in relation to cocaine production. In this regard, the ECDD states that the conversion of coca leaves into a controlled substance is not a necessary consequence. Rather, the relationship between coca and cocaine is that cocaine and other alkaloids are produced through a process of extracting these compounds from the leaves using solvents. 

The document argues that the extraction of coca base paste and the subsequent purification of the base paste into cocaine is easy to perform and does not require expertise. However, it also recognizes that all the products used for extraction, with the exception of kerosene, are substances controlled by international drug conventions. Consequently, as easy as the process may seem, in practice it is not. In addition, there is the issue of volume: to produce 1.5 kilograms of coca base paste, which is the intermediate state between the coca leaf and cocaine, more than 4.2 tons of fresh coca leaves must be used, an exorbitant amount.

Although there will surely be those in the CND vote who prefer not to relax control of the leaf due to concerns about its extractability, it will be crucial for the states that defend this path to argue very well that extractability depends on precursors subject to control and that it also requires volumes of coca leaf that are unlikely to be marketed for legal uses. We are not facing a scenario in which cocaine can be extracted from small exports of coca tea for the small audience that uses this type of product.

3. The uses of coca today and the contested recognition of its nutritional value

The prohibition of coca itself has created obstacles to research of its uses and the nutritional benefits of the plant. The study recognizes that there are two main methods of administration: chewing and infusion. Chewing coca is an ancient cultural and religious practice in the Andean-Amazonian region, while the consumption of coca leaves in infusions is used in these same countries for therapeutic purposes against altitude sickness and other illnesses. The use of coca leaves in flour form, which is simply the product of pulverizing dried coca leaves, is also recognized. It is indicated that in all cases of these methods of administration, a certain amount of cocaine and other alkaloids are absorbed. For example, it has been calculated that consuming an infusion of 1 gram of coca leaf can represent the absorption of 33% of the cocaine present, which translates into the absorption of just 1 milligram of cocaine into the bloodstream. This is a much lower dose of cocaine than that estimated for recreational cocaine use via the nose, which is between 10 and 35 milligrams. However, the evidence cited in the report dates from 2001, and these studies would most likely need to be updated to improve our knowledge on the subject.

It is truly powerful that the report recognizes, in scientific language, many of the properties that Andean-Amazonian indigenous communities have known about this plant for millennia. The coca leaf was found to have antihypertensive, antioxidant, anti-inflammatory, and anti-carcinogenic properties, as well as stimulant, antidiabetic, and anorexigenic (appetite-reducing) effects. Unlike tobacco chewing, it was concluded that coca chewing does not appear to have carcinogenic effects on the mouth or cause DNA damage. 

Finally, regarding dependence on coca leaf consumption, the report indicates that there are no scientific studies in humans, but that the available ethnographic studies show no evidence of withdrawal syndrome or compulsive patterns of use. A study conducted in Peru with a population of 1,333 coca chewers concluded that the prevalence of harmful consumption in the last 12 months was virtually non-existent (0.1%).

4. Indigenous knowledge in the critical review

The WHO parameters for this type of process limit the type of evidence that is considered valid. However, for this particular critical review, a section on traditional uses was added, recognizing that one cannot talk about coca without referring to the cultural practices of the Andean Amazonian indigenous peoples, but this information is gathered from scientific evidence and not directly from the knowledge of indigenous peoples. It is limited to recognizing the use of the coca leaf as an energizer, to alleviate altitude sickness, and to regulate body temperature, among other things. However, it is a short, superficial section that makes little use of direct sources of knowledge from indigenous peoples. 

But behind the sources of this report lies a dilemma: what should be understood as “available scientific evidence”? Can only evidence obtained using the Western scientific method be considered? Such questions are all the more relevant when we note that the report includes few sources from indigenous peoples and that this traditional knowledge may be left out of the picture, with the risk that the critical review process will completely omit the cultural, social, and spiritual issues surrounding the coca leaf.

The ongoing process cannot continue to repeat the mistakes of the past, which led to decades of stigmatization against coca, but above all, against the indigenous peoples who use it. Now, the lack of inclusion of their voices constitutes a risky erasure of the knowledge of those who for centuries have been involved with the plant in its ritual, ceremonial, nutritional, and therapeutic uses. In the words of Jaime Díaz Noscué, indigenous authority and current mayor of Toribío, “there is no Nasa people without the coca leaf. That is why we, from our indigenous worldview, call on international organizations, especially those who direct drug policy, to give special treatment to this coca leaf that is so fundamental to the existence of our ancestral peoples. The coca leaf is medicinal, it is food, it is cultural, it is, I repeat, ancient, and it is very significant for our existence.”