Improving analytical determination of GHB in hair after a single administration through the assessment of promising biomarkers to distinguish between endogenous and exogenous GHB values.

Gamma-hydroxybutyrate (GHB) is a compound with both therapeutic and illicit uses, often involved in cases of drug-facilitated crimes. Due to its rapid metabolism and endogenous production, its detection in hair after a single exposure, is critical, particularly in ambiguous cases where the ratio between endogenous and exogenous value is unclear.

Conventional GHB methods often fail to provide clear evidence of exogenous GHB consumption, particularly in cases of single or low-dose administration. Hyphenated analytical techniques supported by the detection of new biomarkers of consumption, such as GABA, provide useful support in interpreting GHB endogenous and exogenous values and represent a useful strategy to clarify exogenous GHB consumption.

Differentiation between endogenous and exogenous GHB values remains challenging, however, the application of specific biomarkers such as GHB-glucuronide and GABA could potentially provide useful support.

The presence of one or more specific biomarkers reinforces traditional analysis (segmental hair analysis of GHB and determination of a ratio).

These results underline the importance of new potential biomarkers of consumption in improving the reliability and specificity of GHB analysis in hair.

The relationship between endogenous and exogenous GHB values is a critical task in forensic toxicology, especially in cases where results are ambiguous. Biomarkers, such as GABA, offer additional data which can be useful in demonstrating exogenous GHB consumption.

As a product of GHB metabolism, the inclusion of GABA as a biomarker could integrate existing methods and biomarkers, offering a more comprehensive analytical profile for accurately determining and clarifying GHB exposure.

The determination of a single GHB administration in hair is a very difficult task. The inclusion of promising biomarkers, such as GABA, may represent a valid support for a correct interpretation of each case.