In brief
- Energy Control, the drug checking service run by the Asociación Bienestar y Desarrollo (ABD), has published “Hidden Substances,” a report compiling ten years of its own testing data.
- Table 5 classifies 71.5% as unadulterated, 21.3% as addition, 5.9% as substitution and 1.2% as no active substance; these are not purity or safety certificates.
- Among the ten most frequent substances in table 7, heroin (83%) and mephedrone (70%) have high rates; methamphetamine (5%), LSD (6%) and MDMA (8%) have low rates.
Energy Control compiled 29,865 voluntarily submitted samples from 2016 to 2025 to describe composition and patterns observed by its service. This is not a random sample of Spain’s market or an estimate covering all consumption.
Addition and substitution are not the same thing
The report begins by clarifying a common misconception. One issue is adulteration by addition: the sample contains the expected drug alongside added substances. Quite another is total substitution: the declared substance is not identified and others are. Unadulterated means only the declared substance was identified within analytical limits; it does not certify absolute absence of any added material or risk. Table 5 reports 71.5% unadulterated, 21.3% addition, 5.9% substitution and 1.2% no active substance detected; rounding is retained. The PDF text says 71.4% where the table says 71.5%, and table 6 labels 6,372 unadulterated although the text defines 8,147 as adulterated. These are unresolved discrepancies here; percentages are not recalculated or causes invented. Caffeine was the most frequently detected adulterant, followed by levamisole and phenacetin; local anesthetics also appear.
Vast differences across substances
The report’s most actionable finding is that adulteration is not distributed equally. At the high end are heroin, with 83% of samples adulterated, and mephedrone (4-MMC) at 70%, followed by amphetamine (60%), 3-MMC (49%), and cocaine (42%). At the lower end are LSD (6%), MDMA (8%), and methamphetamine (5%), with ketamine at 15% and 2C-B at 25%, among the ten most frequent substances in that table. The report describes more frequent detection of certain cathinones since 2022; frequency in samples received is not prevalence across the entire market. This review has not established chemical diversity for each year of Spain’s whole market.
What this means
The percentages describe self-selected samples rather than the entire market. The report uses presence or absence without concentrations in its matrix and acknowledges that substances below method-specific detection limits may be missed. Testing reduces uncertainty but does not guarantee complete composition, purity or safe consumption. The report received National Drug Plan funding; this does not establish each service’s current funding. You can find context in our guide to harm reduction and responsible use, as well as our coverage of the synthetic opioids test strips fail to detect, as context on the limits of particular detection tools.
Source
- Energy Control (ABD). Sustancias ocultas: clasificación, prevalencia y riesgos de los adulterantes de las drogas consumidas con fines recreativos. Energy Control, May 29, 2026.
Educational content written from a harm reduction perspective and with respect for individual freedom. It is not a substitute for advice from a healthcare professional and is not intended to encourage or condemn any drug use.
