{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,2,19]],"date-time":"2026-02-19T00:07:23Z","timestamp":1771459643887,"version":"3.50.1"},"reference-count":22,"publisher":"Oxford University Press (OUP)","issue":"6","license":[{"start":{"date-parts":[[2025,6,5]],"date-time":"2025-06-05T00:00:00Z","timestamp":1749081600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/academic.oup.com\/pages\/standard-publication-reuse-rights"}],"funder":[{"DOI":"10.13039\/501100003196","name":"Italian Ministry of Health","doi-asserted-by":"crossref","id":[{"id":"10.13039\/501100003196","id-type":"DOI","asserted-by":"crossref"}]},{"DOI":"10.13039\/501100003196","name":"Italian Ministry of Health","doi-asserted-by":"crossref","id":[{"id":"10.13039\/501100003196","id-type":"DOI","asserted-by":"crossref"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"published-print":{"date-parts":[[2025,7,1]]},"abstract":"<jats:title>Abstract<\/jats:title>\n               <jats:p>Alexamorelin is a synthetic peptide and growth hormone secretagogue (GHS) with potential performance-enhancing properties, making its use and abuse a topic of interest in clinical research and doping monitoring. Alexamorelin mimics the natural peptide hormone ghrelin by binding to the GHS type 1a receptor (GHS-R1a) in the pituitary gland, thereby promoting endogenous growth hormone release. Identifying alexamorelin and\/or its metabolite biomarkers is crucial for effective doping controls. The purpose of this study was to determine and characterize biomarkers associated with alexamorelin intake. In silico metabolite predictions were performed using GLORYx freeware, and in vitro incubations were conducted with pooled human hepatocytes from 10 donors. Samples were analysed using liquid chromatography\u2013high-resolution tandem mass spectrometry (LC\u2013HRMS\/MS), with data processed through Thermo Scientific\u2019s Compound Discoverer. GLORYx predicted 21 single-reaction metabolites. N-Acetylation was identified as the primary transformation, with the highest probability score (98%), and occurring either at the C-terminal Ala or the N-terminal Lys. Other predicted transformations included N-oxidation, hydroxylation, amide hydrolysis, oxidative deamination, and phase II N-glucuronidation, with probability scores below 40%. All these transformations were predicted to occur at the two C-terminal (Ala or His) or N-terminal (d-Phe or Lys) amino acids. After 3\u2009h of incubation with hepatocytes, only one metabolite (known as examorelin or hexarelin) was detected, resulting from the C-terminal cleavage of the Ala amino acid; this metabolic reaction is mediated by a carboxypeptidase. The alexamorelin signal decreased approximately 150-fold after 3\u2009h, indicating significant hepatic metabolism. However, examorelin itself is a commercially available GHS secretagogue, and thus, it is not specific to alexamorelin consumption. Detecting alexamorelin remains critical to documenting its use.<\/jats:p>","DOI":"10.1093\/jat\/bkaf038","type":"journal-article","created":{"date-parts":[[2025,5,12]],"date-time":"2025-05-12T07:51:43Z","timestamp":1747036303000},"page":"394-400","source":"Crossref","is-referenced-by-count":1,"title":["Identification of alexamorelin consumption biomarkers using human hepatocyte incubations and high-resolution mass spectrometry"],"prefix":"10.1093","volume":"49","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-1386-7477","authenticated-orcid":false,"given":"Elizabeth","family":"Pobee","sequence":"first","affiliation":[{"name":"Unit of Forensic Toxicology, Section of Legal Medicine, Department of Biomedical Sciences and Public Health, Marche Polytechnic University , Ancona, AN 60126,","place":["Italy"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Gloria","family":"Daziani","sequence":"additional","affiliation":[{"name":"Unit of Forensic Toxicology, Section of Legal Medicine, Department of Biomedical Sciences and Public Health, Marche Polytechnic University , Ancona, AN 60126,","place":["Italy"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Prince S","family":"Gameli","sequence":"additional","affiliation":[{"name":"Unit of Forensic Toxicology, Section of Legal Medicine, Department of Biomedical Sciences and Public Health, Marche Polytechnic University , Ancona, AN 60126,","place":["Italy"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Giuseppe","family":"Basile","sequence":"additional","affiliation":[{"name":"Unit of Forensic Toxicology, Section of Legal Medicine, Department of Biomedical Sciences and Public Health, Marche Polytechnic University , Ancona, AN 60126,","place":["Italy"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3332-9518","authenticated-orcid":false,"given":"Jeremy","family":"Carlier","sequence":"additional","affiliation":[{"name":"Unit of Forensic Toxicology, Section of Legal Medicine, Department of Biomedical Sciences and Public Health, Marche Polytechnic University , Ancona, AN 60126,","place":["Italy"]}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Anastasio","family":"Tini","sequence":"additional","affiliation":[{"name":"Unit of Forensic Toxicology, Section of Legal Medicine, Department of Biomedical Sciences and Public Health, Marche Polytechnic University , Ancona, AN 60126,","place":["Italy"]}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"286","published-online":{"date-parts":[[2025,6,5]]},"reference":[{"key":"2025091920262864100_R1","doi-asserted-by":"publisher","first-page":"89","DOI":"10.1161\/CIRCULATIONAHA.116.022535","article-title":"Cardiovascular effects of performance-enhancing drugs","volume":"135","author":"La Gerche","year":"2017","journal-title":"Circulation"},{"key":"2025091920262864100_R2","doi-asserted-by":"publisher","first-page":"100","DOI":"10.7417\/CT.2019.2117","article-title":"The unethicality of doping in sports","volume":"170","author":"Palmi","year":"2019","journal-title":"Clin Ter"},{"key":"2025091920262864100_R3","doi-asserted-by":"publisher","first-page":"341","DOI":"10.1210\/er.2013-1058","article-title":"Adverse health consequences of performance-enhancing drugs: an endocrine society scientific statement","volume":"35","author":"Pope","year":"2014","journal-title":"Endocr Rev"},{"key":"2025091920262864100_R4","author":"World Anti-Doping Agency. 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