Summary: A new study collected data on drug use by swabbing smartphone surfaces and then analyzing residues. It successfully identified various drugs, including MDMA, cocaine, THC, and others. However, the method has limitations like unknown drug stability on surfaces and contamination risks.


  1. The study presents a novel, non-invasive approach to assess drug use through smartphone surfaces.
  2. Understanding local drug consumption patterns can inform public health interventions and aid in managing intoxications.
  3. Despite its potential, the method requires further validation and refinement to address limitations and improve reliability.

A new simple and convenient method to collect drug use data from the surface of a smartphone is revealed for the first time in a study published in De Gruyter’s Clinical Chemistry and Laboratory Medicine. By helping clinicians understand what drugs people are taking in certain contexts, the research could protect public health and improve the treatment of patients suspected of overdosing. 

Methods of Toxicology Testing

Understanding the most common drugs in a particular area, who uses them, when they use them and in what contexts can help inform life-saving treatment decisions but given the illegal nature of many recreational drugs, such data are not always easy to obtain. Researchers can employ indirect techniques, such as analyzing wastewater or conduct anonymous surveys with drug users, pairing the results with toxicological measurements such as blood or urine samples. However, such approaches can be inaccurate and too invasive for routine use.

Drug Testing with a Smartphone

Théo Willeman, PharmD, of Grenoble Alpes University Hospital, France and colleagues explored if the smartphone could be a more convenient way to track drug use. Fingerprints on a phone’s surface contain sweat and sebum that can reveal the presence of drugs, and the surface itself can retain traces of any drugs consumed directly from it.

The researchers invited drug users at techno and trance music events in France to anonymously complete a questionnaire about their drug use, and then dry swabbed the surface of their smartphones. The swabs were later analyzed using liquid chromatography to detect drugs.

Swabbing for Drugs

The researchers collected and analyzed 122 swabs and successfully identified a variety of drugs. The three most common were MDMA, cocaine, and THC, but the researchers also found ketamine, LSD, methamphetamine, CBD, heroin, and mescaline. The results confirm that smartphones can successfully provide a convenient and non-invasive way to assess drug use.

The study has some limitations. For instance, the stability of drug molecules on a smartphone surface is not known, and this could influence the results if substances degrade quickly or slowly. The method is also limited by the possibility that several people may have handled the smartphone or it could be contaminated by drug traces in the environment. However, the study is intended as a proof-of-concept, and further research can cast light on these unknowns and further validate the technique. 

Further reading: New Forensic Toxicology Tech for the Detection of Drugs of Abuse 

“The opioid crisis in the US was recognized as a public health emergency by the US President in 2016,” says Willeman. “As a result, developing new tools to perform toxico-epidemiology studies is crucial, and identifying which substances are consumed in a particular area may help medical teams managing potential intoxications.”