Why Forensic Labs Struggle to Detect Semaglutide — and Why It Matters for Legal Cases | Research

The takeaway

Semaglutide's large molecular structure and limited blood stability create significant challenges for forensic detection, raising concerns about its potential role in impaired driving cases, unexplained deaths, and misuse scenarios.

No standard forensic assay exists
Despite millions of people taking semaglutide, forensic laboratories lack validated methods to detect or quantify it in blood samples — meaning its role in impaired driving, drug interactions, or deaths may go unrecognized.

What the researchers found

The review identifies several forensic challenges posed by semaglutide and other GLP-1 agonists:

- Semaglutide's large, highly charged molecular structure makes it difficult to detect and quantify using standard forensic laboratory instrumentation

- The drug may have limited stability in whole blood samples, further complicating post-mortem analysis

- Side effects relevant to forensic cases include hypoglycemia (which can impair driving and other performance), drug-drug interactions, and potential contribution to unexpected fatalities

- Off-label use and misuse for weight loss expand the population potentially affected

- No robust analytical methods currently exist for routine forensic toxicology casework involving semaglutide

Why it matters

Millions of Americans now take semaglutide, yet forensic laboratories cannot reliably test for it. This creates a blind spot in medicolegal investigations: if semaglutide-induced hypoglycemia causes a car crash or contributes to a death, the drug's involvement may never be identified. As off-label and unregulated weight-loss use expands, the forensic significance of this detection gap grows.

How the study worked

This is a narrative review examining the pharmacokinetics, side effects, drug interactions, and analytical challenges of semaglutide from a forensic medicine perspective. The author synthesized available pharmacological literature with forensic toxicology considerations.

What this study cannot tell us

This is a brief narrative review by a single author, not a systematic analysis. No new experimental data are presented. The review focuses primarily on semaglutide and may not fully address analytical challenges of other GLP-1 RAs. Specific case examples linking semaglutide to forensic outcomes are not provided. The extent to which semaglutide actually contributes to impaired driving or fatalities is unknown.

How to read the evidence

This is a narrative review raising awareness of an emerging forensic challenge. It does not present new experimental data or systematic analysis. Its value lies in identifying an important gap in forensic toxicology capabilities rather than providing evidence-based solutions.

When this study was published

Published in 2025, this review is timely as semaglutide prescriptions continue to surge worldwide, making the forensic detection gap increasingly relevant to legal and medical examiner communities.

The bigger picture

Forensic toxicology has historically focused on detecting small molecules — drugs of abuse, alcohol, common medications. The rise of peptide-based therapeutics like semaglutide presents a fundamentally new analytical challenge. As biologic drugs become more common in the general population, forensic labs will need to develop entirely new methods to detect these large molecules. This paper is an early call to action for the forensic science community to address this emerging gap.

Questions still open

How many traffic accidents or unexplained deaths may involve undetected semaglutide-induced hypoglycemia?
What analytical methods can forensic laboratories develop to reliably detect and quantify semaglutide in post-mortem blood samples?
Should semaglutide users receive warnings about potential driving impairment similar to those for insulin and other hypoglycemia-causing drugs?

Common questions

Why can't forensic labs detect semaglutide in blood?

Most forensic toxicology labs are set up to detect small molecules like alcohol, opioids, and common drugs. Semaglutide is a much larger peptide molecule with a complex, highly charged structure that doesn't work well with standard forensic testing equipment. Additionally, semaglutide may break down in stored blood samples, making it even harder to detect in cases where testing happens days or weeks after death or an incident.

Could semaglutide cause a car accident?

Potentially, yes. Semaglutide can cause hypoglycemia (dangerously low blood sugar), especially when combined with other diabetes medications. Hypoglycemia can cause confusion, dizziness, impaired vision, and loss of consciousness — all of which could lead to a driving accident. The concern raised by this review is that if such an accident occurred, forensic labs might not be able to detect semaglutide in the driver's blood, so the drug's contribution would go unrecognized.

Read the original research

Semaglutide and GLP-1 Agonists: Forensic and Medicolegal Implications.

The American journal of forensic medicine and pathology, 46(3), 222-228

View on PubMed ↗Publisher’s paper ↗

Citation

Fagiola, Michael. (2025). Semaglutide and GLP-1 Agonists: Forensic and Medicolegal Implications.. The American journal of forensic medicine and pathology, 46(3), 222-228. https://doi.org/10.1097/PAF.0000000000001044