The Evolution of Drug Checking

Part One of Three: What is Drug Checking?

By: Shelby Arena

       The increasing unpredictability of the unregulated drug market has made drug checking a critical public health intervention. Drug checking services aim to reduce harm by allowing individuals to identify the presence of contaminants, cuts, or other unexpected components in a given sample. As the overdose epidemic continues to evolve alongside the drug supply across the United States, it is vital to examine the development of drug checking methods and how technology and community engagement come together to help individuals be more informed about the substances they use.

Origins in Biological Chemistry and Informal Harm Reduction

       Drug checking has roots in the biological sciences of the 19th century. Early biochemists developed methods of chemical testing to determine the concentration of a substance by measuring how much it absorbed a specific wavelength of light (Jensen, 2014). One of the earliest forms of drug identification, colorimetric analysis, involved adding reagents to a sample to observe color changes that could indicate the presence of specific substances.

       In the 1960s and 1970s, widespread recreational drug use led to informal drug checking practices. These often involved sensory-based assessments, where individuals relied on taste, smell, visual appearance, and physical response to gauge a substance’s effects. Information about contaminated drugs was primarily spread through word of mouth. A notable example occurred at the 1969 Woodstock festival, where an emcee famously warned concertgoers not to take the “brown acid,” an early instance of community-based harm reduction (Boulton, 2019). As the internet became more accessible in the 1990s and 2000s, online platforms such as Erowid allowed users to document and share their experiences with psychoactive substances, creating a more readily available resource for people to gather more information about their drugs (About the Erowid Experience Vaults, 2025).

The Rise of Reagent Testing Kits

       The 1970s marked the rise in availability of reagent testing kits for drug identification. These kits provided a simple, low-cost method for presumptive drug testing using chemical reactions that produce color changes in the presence of specific compounds. The Marquis reagent, developed in the early 1970s, became one of the most widely used tools for detecting MDMA and amphetamines (Palamar & Barratt, 2018). Additional reagents followed, including Ehrlich’s reagent used primarily to detect LSD, Mandelin’s reagent for ketamine and specific opiates, and Simon’s reagent to distinguish MDMA from MDA (Nasir, 2025).

       Although reagent kits are a relatively quick and accessible means of testing, they are not without limitations. Reagents cannot determine levels of potency, purity, or give exact confirmation of what is in a substance (Nasir, 2025).

Adaptation of Test Strips for Harm Reduction

Machine Drug Checking

       Advances in analytical chemistry during the late 20th and early 21st centuries led to the integration of high-precision instruments into drug checking services. Gas chromatography–mass spectrometry (GC-MS), a method developed in the late 1960s, became the gold standard for laboratory-based substance identification due to its ability to separate and accurately identify chemical compounds (Lipps, 2015). However, the high cost, size, and technical expertise required to run GC-MS tests limited its utility in community or field settings (Rose et al., 2023).

       Another drug checking technology, Fourier-transform infrared spectroscopy (FTIR), became widespread in the 1990s. FTIR uses infrared light to create a spectrum used to identify unknown substances. The introduction of the FTIR has allowed for rapid, on-site analysis as these machines are capable of identifying compounds within a few minutes (Jasco, 2022). Due to their accessibility and smaller footprint as compared to GC-MS machines, FTIR machines have been increasingly adopted by harm reduction services for point of care testing.

Conclusion

       Drug checking has evolved from foundations in biological chemistry into a key element of harm reduction. The history of drug checking is a story of scientific innovation, community knowledge sharing, and reactionary public health policy. As these technologies become more accessible and user-friendly, and as legal frameworks and public attitudes begin to shift, drug checking is bound to become a standard pillar in substance use services.