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Topic:Doping

Doping in horses refers to the administration of prohibited substances or methods to enhance performance or alter behavior during competitions. This practice is a concern in equestrian sports due to its potential impact on animal welfare, fair play, and the integrity of the sport. Substances used in doping can range from stimulants and painkillers to sedatives and anti-inflammatory drugs. Detection methods include blood and urine tests, designed to identify the presence of banned substances or their metabolites. This page compiles peer-reviewed research studies and scholarly articles that explore the detection methods, regulatory frameworks, and ethical considerations associated with doping in equine sports.
Kavain detection in post-race equine urine sample: A case report.
Drug testing and analysis    January 26, 2021   Volume 13, Issue 4 883-886 doi: 10.1002/dta.2996
Barnabé A, Moulard Y, Trevisiol S, Boyer S, Caroff M, Taleb W, Tendon S, Drif L, Delcourt V, Popot MA, Bailly-Chouriberry L.The study focuses on the discovery of kavain, a natural-occurring compound of the plant Piper methysticum, in a post-race urine sample of a horse. The researchers traced the potential source […]
Detection and longitudinal distribution of GW1516 and its metabolites in equine hair for doping control using liquid chromatography/high-resolution mass spectrometry.
Rapid communications in mass spectrometry : RCM    January 21, 2021   Volume 35, Issue 8 e9050 doi: 10.1002/rcm.9050
Ishii H, Shibuya M, Leung GN, Nozawa S, Yamashita S, Yamada M, Kushiro A, Kasashima Y, Okada J, Kawasaki K, Kijima-Suda I.GW1516 is a peroxisome proliferator-activated receptor-δ (PPAR-δ) agonist that is banned in horseracing and equestrian sports. Long-term detection and longitudinal distribution of GW1516 in the mane of a horse are reported for the first time and this hair analysis could prolong the detection window of GW1516 for doping control. Methods: Mane hairs were divided into three segments (0-7, 7-15, and >15 cm from the cut end) and completely pulverized and homogenized for analysis. The pulverized hair samples were extracted with methanol followed by further purification and the extracts were a...
Label-free proteomics for discovering biomarker candidates of RAD140 administration to castrated horses.
Drug testing and analysis    January 5, 2021   Volume 13, Issue 5 1034-1047 doi: 10.1002/dta.2988
Cheung HW, Wong KS, To NS, Bond AJ, Farrington AF, Prabhu A, Curl P, Wan TSM, Ho ENM.Selective androgen receptor (AR) modulators (SARMs) are potent anabolic agents with a high potential of misuse in horseracing and equestrian sports. In this study, we applied label-free proteomics to discover plasma protein biomarkers in geldings (castrated horses) after administration with a popular SARM named RAD140. Tryptic peptides were prepared from plasma samples and analyzed by nano-flow ultrahigh-performance liquid chromatography-high-resolution tandem mass spectrometry (nano-UHPLC-HRMS/MS) using data-independent acquisition (DIA) method. Orthogonal projection on latent structure-discr...
Whole-genome resequencing using genomic DNA extracted from horsehair roots for gene-doping control in horse sports.
Journal of equine science    December 18, 2020   Volume 31, Issue 4 75-83 doi: 10.1294/jes.31.75
Tozaki T, Ohnuma A, Kikuchi M, Ishige T, Kakoi H, Hirota KI, Hamilton NA, Kusano K, Nagata SI.Gene doping is prohibited in horseracing and equestrian sports. In previous studies, we developed non-targeted transgene and genome editing detection methods based on whole genome resequencing (WGR) using genomic DNA extracted from whole blood. In this study, we aimed to develop a WGR method using DNA extracts from hair roots. Hair roots are a preferred substrate because their collection is less invasive than blood collection. Hair is also easier to store for long periods of time. Although almost all genomic DNA extracted from hair root samples stored for years at room temperature was degraded...
Metabolic study of GW1516 in equine urine using liquid chromatography/electrospray ionization Q-Exactive high-resolution mass spectrometry for doping control.
Rapid communications in mass spectrometry : RCM    December 16, 2020   Volume 35, Issue 5 e9028 doi: 10.1002/rcm.9028
Ishii H, Shibuya M, Leung GN, Yamashita S, Yamada M, Kushiro A, Kasashima Y, Okada J, Kawasaki K, Kijima-Suda I.The use of GW1516, a peroxisome proliferator-activated receptor δ (PPAR δ) agonist, is strictly prohibited in both horseracing and equestrian competitions. However, little is known about its metabolic fate in horses. To the best of our knowledge, this is the first reported metabolic study of GW1516 in equine urine. Methods: Urine samples obtained from a thoroughbred after nasoesophageal administration with GW1516 were protein-precipitated and the supernatants were subsequently analyzed by liquid chromatography/electrospray ionization high-resolution mass spectrometry (LC/ESI-HRMS) with a Q-E...
Metabolism and excretion of the benzodiazepine analogue etizolam in the horse.
Drug testing and analysis    November 15, 2020   Volume 13, Issue 3 583-594 doi: 10.1002/dta.2967
Johnson E, van Heemst J, Benavides J, Gray B.Etizolam is a benzodiazepine analogue that is approved for use in Japan, Italy and India but has recently appeared as a nonapproved product on the illicit drug market in Europe and North America. Etizolam was identified in a crystalline material seized at a Kentucky racetrack, raising concerns that this drug may have been used in racing. The aim of this study was to characterize the metabolism and excretion of etizolam in horses to generate information on its disposition and to incorporate the correct urinary and serum target analytes into anti-doping screening procedures. Etizolam was adminis...
Evaluation of dried blood spots as an alternative sample matrix for equine antidoping analysis.
Drug testing and analysis    October 19, 2020   Volume 13, Issue 2 386-396 doi: 10.1002/dta.2934
Moeller BC, Yang Z.Controlling the abuse of prohibited substances such as anabolic steroids, selective androgen receptor modulators, β-adrenoceptor agonists, and blood doping agents is of great interest to racing authorities. The use of dried blood spots (DBS) as an alternative sampling approach may be a feasible approach for controlling the use of these agents. To assess the feasibility of using DBS in equine blood, an 11-min liquid chromatography-mass spectrometry method was developed on a triple quadrupole mass spectrometer following extraction from Whatman 903 DBS cards. A total of 50 compounds across multi...
Equine metabolism of the selective androgen receptor modulator AC-262536 in vitro and in urine, plasma and hair following oral administration.
Drug testing and analysis    October 15, 2020   Volume 13, Issue 2 369-385 doi: 10.1002/dta.2932
Cutler C, Viljanto M, Taylor P, Habershon-Butcher J, Muir T, Biddle S, Van Eenoo P.AC-262536 is one of a number of selective androgen receptor modulators that are being developed by the pharmaceutical industry for treatment of a range of clinical conditions including androgen replacement therapy. Though not available therapeutically, selective androgen receptor modulators are widely available to purchase online as (illegal) supplement products. The growth- and bone-promoting effects, along with fewer associated negative side effects compared with anabolic-androgenic steroids, make these compounds a significant threat with regard to doping control in sport. The aim of this st...
A duplex qPCR assay for human erythropoietin (EPO) transgene to control gene doping in horses.
Drug testing and analysis    October 14, 2020   Volume 13, Issue 1 113-121 doi: 10.1002/dta.2907
Cheung HW, Wong KS, Lin VYC, Wan TSM, Ho ENM.The misuse of genetic manipulation technology to enhance athletic performance is termed gene doping which is prohibited in human sports, horseracing, and equestrian sports. Although many qPCR assays have been developed, most assays employ genomic DNA (gDNA) from humans, non-human primates, and mice as a background and they may not be applicable for testing horse samples. This study aimed to develop a qPCR assay for the detection of human erythropoietin (hEPO) transgene in horse blood cells where the viral vectors used in gene therapy can reside for months. For the detection of hEPO transgene, ...
Detection and identification of ACP-105 and its metabolites in equine urine using LC/MS/MS after oral administration.
Drug testing and analysis    September 6, 2020   Volume 13, Issue 2 299-317 doi: 10.1002/dta.2918
Subhahar MB, Karakka Kal AK, Philip M, K Karatt T, N I, Vazhat RA, M P MA.ACP-105 is a novel nonsteroidal selective androgen receptor modulator (SARM) with a tissue-specific agonist effect and does not have side effects associated with the use of common androgens. This research reports a comprehensive study for the detection of ACP-105 and its metabolites in racehorses after oral administration (in vivo) and postulating its structures using mass spectrometric techniques. To obtain the metabolic profile of ACP-105, a selective and reliable LC-MS/MS method was developed. The chemical structures of the metabolites were determined based on their fragmentation pattern, a...
Doping control analysis of GW1516 in equine plasma using liquid chromatography/electrospray ionization Q-Exactive high-resolution mass spectrometry.
Rapid communications in mass spectrometry : RCM    August 11, 2020   Volume 34, Issue 23 e8920 doi: 10.1002/rcm.8920
Ishii H, Leung GN, Yamashita S, Yamada M, Kushiro A, Kasashima Y, Okada J, Kawasaki K, Kijima-Suda I.GW1516 is a peroxisome proliferator-activated receptor-δ agonist in the class of hormones and metabolic modulators. The use of GW1516 is banned in both horseracing and equestrian competitions. To the best of our knowledge, this is the first metabolic study of GW1516 in horses. Methods: After protein precipitation of pre- and post-administration plasma GW1516 samples, the supernatants were analyzed using liquid chromatography/electrospray ionization Q-Exactive high-resolution mass spectrometry to detect GW1516 and its metabolites. Monoisotopic ions of GW1516 and its metabolites were monitored ...
Detection of non-targeted transgenes by whole-genome resequencing for gene-doping control.
Gene therapy    August 7, 2020   Volume 28, Issue 3-4 199-205 doi: 10.1038/s41434-020-00185-y
Tozaki T, Ohnuma A, Takasu M, Nakamura K, Kikuchi M, Ishige T, Kakoi H, Hirora KI, Tamura N, Kusano K, Nagata SI.Gene doping has raised concerns in human and equestrian sports and the horseracing industry. There are two possible types of gene doping in the sports and racing industry: (1) administration of a gene-doping substance to postnatal animals and (2) generation of genetically engineered animals by modifying eggs. In this study, we aimed to identify genetically engineered animals by whole-genome resequencing (WGR) for gene-doping control. Transgenic cell lines, in which the erythropoietin gene (EPO) cDNA form was inserted into the genome of horse fibroblasts, were constructed as a model of genetica...
Doping control analysis of total arsenic in equine plasma.
Drug testing and analysis    July 20, 2020   Volume 12, Issue 10 1462-1469 doi: 10.1002/dta.2896
Chan GHM, Tang W, Curl P, Lin Y, Wan TSM, Ho ENM.Arsenic can be easily found in our surrounding environment. Because of its ubiquitous nature, horse urine and blood invariably contain low levels of arsenic. Nevertheless, inorganic arsenic, despite its general use as a tonic for horses, is an effective doping agent having a deleterious effect because of its ability to induce gastroenteritis. The misuse of arsenic in horseracing has been controlled by an international urinary threshold of total arsenic at 0.3 μg/mL. However, an equivalent threshold for total arsenic in plasma is yet to be established. In this study, an inductively coupled pla...
Detection of bioactive peptides including gonadotrophin-releasing factors (GnRHs) in horse urine using ultra-high performance liquid chromatography-high resolution mass spectrometry (UHPLC/HRMS).
Drug testing and analysis    July 17, 2020   Volume 12, Issue 9 1274-1286 doi: 10.1002/dta.2880
Kwok KY, Choi TLS, Kwok WH, Lau MY, Leung EMK, Leung GNW, Wong JKY, Wan TSM, Adrian FF, Prabhu A, Ho ENM.The use of bioactive peptides as a doping agent in both human and animal sports has become increasingly popular in recent years. As such, methods to control the misuse of bioactive peptides in equine sports have received attention. This paper describes a sensitive accurate mass method for the detection of 40 bioactive peptides and two non-peptide growth hormone secretagogues (< 2 kDa) at low pg/mL levels in horse urine using ultra-high performance liquid chromatography-high resolution mass spectrometry (UHPLC/HRMS). A simple mixed-mode cation exchange solid-phase extraction (SPE) cartridge was...
Application of a non-target variable data independent workflow (vDIA) for the screening of prohibited substances in doping control testing.
Drug testing and analysis    July 15, 2020   Volume 13, Issue 5 1008-1033 doi: 10.1002/dta.2881
Leung DKK, Wong ASY, Zhou QL, Wan TSM, Ho ENM.A non-target variable Data Independent Acquisition (vDIA) workflow based on accurate mass measurements using a Q Exactive OrbiTrap is presented for the first time for equine doping control testing. The vDIA workflow uses a combination of MS1 events (1 to 2) and multiple vDIA events to cover the analytes of interest. The workflow basically captures a digital image of a sample allowing all relevant MS1 and MS2 data to be recorded. In theory, the workflow can accommodate an unlimited number of analytes as long as they are amenable to the sample extraction protocol and fall within the mass limits ...
An innovative derivatization-free IC-MS/MS method for the detection of bisphosphonates in horse plasma.
Drug testing and analysis    July 14, 2020   Volume 12, Issue 10 1452-1461 doi: 10.1002/dta.2892
Garcia P, Pinètre J, Morel S, Jaubert M, Deruy X, Perot I, Delcourt V, Loup B, Popot MA, Bailly-Chouriberry L.Bisphosphonates are prohibited drugs according to Article 6 of the International Agreement on Breeding, Racing and Wagering of the International Federation of Horseracing Authorities (IFHA) and the International Equestrian Federation (FEI). These compounds are used for the treatment of lameness, navicular and bone diseases in horses and are divided into two groups: non-nitrogen-containing bisphosphonate drugs (e.g. clodronic acid) and nitrogen-containing bisphosphonate drugs (e.g. zoledronic acid). Their hydrophilic properties and the high affinity for the bone matrix make the control of their...
Quantification and validation of nine nonsteroidal anti-inflammatory drugs in equine urine using gas chromatography-mass spectrometry for doping control.
Drug testing and analysis    June 28, 2020   Volume 12, Issue 8 1065-1077 doi: 10.1002/dta.2864
Göktaş EF, Kabil E, Arıöz F.Nonsteroidal anti-inflammatory drugs (NSAIDs) are commonly used in therapeutic doses in human and veterinary medicine for the treatment of inflammation, pain, and fever. A method for the simultaneous determination of nine NSAIDs, known as therapeutic prohibited substances, in equine urine was developed and fully validated according to the European Commission Decision 2002/657/EC and Association of Official Racing Chemists criteria. The validation was performed for naproxen, flunixin, ketoprofen, diclofenac, eltenac, meclofenamic acid, phenylbutazone, vedaprofen, and carprofen in equine urine i...
Quantitative analysis of paracetamol, metacetamol, and orthocetamol in equine urine from racehorses in Japan using liquid chromatography-electrospray ionization-tandem mass spectrometry.
Drug testing and analysis    June 24, 2020   Volume 12, Issue 8 1196-1202 doi: 10.1002/dta.2860
Ishii H, Obara T, Kusano K, Kijima-Suda I.Paracetamol is commonly used as an over-the-counter analgesic and antipyretic medication for humans, but not sold as a legitimate therapeutic medication for horses in Japan. However, paracetamol is commonly found in horses together with its two isomers, metacetamol and orthocetamol. We previously reported that paracetamol and orthocetamol were both present in selected feed consumed by Japanese racehorses. For the purpose of the doping control of paracetamol in local Japanese horses, we proposed establishing residue limits (Japanese residue limits, JRLs) to minimize the risk of reporting parace...
Determination of bromhexine and its metabolites in equine serum samples by liquid chromatography – Tandem mass spectrometry: Applicability to the elimination study after single oral dose.
Journal of chromatography. B, Analytical technologies in the biomedical and life sciences    May 30, 2020   Volume 1151 122197 doi: 10.1016/j.jchromb.2020.122197
Waraksa E, Owczarek K, Kubica P, Kłodzińska E, Ozimek M, Wrzesień R, Bobrowska-Korczak B, Namieśnik J.Bromhexine (BH), expectorant used in the treatment of respiratory disorders associated with viscid or excessive mucus, is not permitted for use in the competing horse by many authorities in horseracing and Olympic disciplines. Metabolic studies are of the great importance in anti-doping field because they allow for updating the selection of the most appropriate markers for prohibited substances, such as metabolites present at higher concentration levels and/or lasted for a longer period of time in biological samples than a parent drug. This study describes LC-MS/MS-based method for simultaneou...
Enhanced UHPLC-MS/MS screening of selective androgen receptor modulators following urine hydrolysis.
MethodsX    May 21, 2020   Volume 7 100926 doi: 10.1016/j.mex.2020.100926
Gadaj A, Ventura E, Healy J, Botrè F, Sterk SS, Buckley T, Mooney MH.Selective androgen receptor modulators (SARMs) represent non-steroidal agents commonly abused in human and animal (i.e. equine, canine) sports, with potential for further misuse as growth promoting agents in livestock-based farming. As a direct response to the real and possible implications of illicit application in both sport as well as food production systems, this study incorporated enzymatic hydrolysis (β-glucuronidase/arylsulfatase) into a previously established protocol while maintaining the minimal volume (200 µL) of urine sample required to detect SARMs encompassing various pharmacop...
A high-throughput and broad-spectrum screening method for analysing over 120 drugs in horse urine using liquid chromatography-high-resolution mass spectrometry.
Drug testing and analysis    May 18, 2020   Volume 12, Issue 7 900-917 doi: 10.1002/dta.2799
Wong JKY, Chan GHM, Choi TLS, Kwok KY, Lau MY, Leung GNW, Wan TSM, Ho ENM.A high-throughput method has been developed for the doping control analysis of 124 drug targets, processing up to 154 horse urine samples in as short as 4.5 h, from the time the samples arrive at the laboratory to the reporting deadline of 30 min before the first race, including sample receipt and registration, preparation and instrument analysis and data vetting time. Sample preparation involves a brief enzyme hydrolysis step (30 min) to detect both free and glucuronide-conjugated drug targets. This is followed by extraction using solid-supported liquid extraction (SLE) and analysis using liq...
Presence of Antimicrobials in Postrace Samples in Japanese Thoroughbred Racing.
Journal of equine veterinary science    May 12, 2020   Volume 91 103115 doi: 10.1016/j.jevs.2020.103115
Mizobe F, Mori M, Nagata SI, Yamashita S, Okada J, Kusano K.Ever since 'One Health' concept was introduced in early 2000s, judicious use of antimicrobials by veterinarians has become an issue of great concern. Recently, findings of anti-inflammatory effects in certain types of antimicrobials have raised a subject for discussion among racing authorities. Regulatory framework of antimicrobials in racing should be based on best interest of horse welfare and doping control perspective, but basic data on prevalence of antimicrobials are lacking. Analysis of 100 postrace urinary samples collected from 10 Japanese racecourses by targeting 21 antimicrobials us...
Doping control analysis of antipsychotics and other prohibited substances in equine plasma by liquid chromatography/tandem mass spectrometry.
Journal of chromatography. B, Analytical technologies in the biomedical and life sciences    May 1, 2020   Volume 1147 122132 doi: 10.1016/j.jchromb.2020.122132
Wong ASY, Choi TLS, Kwok KY, Wong JKY, Wan TSM, Ho ENM.Antipsychotics are banned substances and considered by the Fédération Equestrian Internationale (FEI) to have no legitimate use in equine medicine and/or have a high potential for abuse. These substances are also prohibited in horseracing according to Article 6 of the International Agreement on Breeding, Racing and Wagering (published by the International Federation of Horseracing Authorities). Over the years, antipsychotics have been abused or misused in equestrian sports and horseracing. A recent review of literature shows that there is yet a comprehensive screening method for antipsychoti...
Microfluidic Quantitative PCR Detection of 12 Transgenes from Horse Plasma for Gene Doping Control.
Genes    April 23, 2020   Volume 11, Issue 4 457 doi: 10.3390/genes11040457
Tozaki T, Ohnuma A, Kikuchi M, Ishige T, Kakoi H, Hirota KI, Kusano K, Nagata SI.Gene doping, an activity which abuses and misuses gene therapy, is a major concern in sports and horseracing industries. Effective methods capable of detecting and monitoring gene doping are urgently needed. Although several PCR-based methods that detect transgenes have been developed, many of them focus only on a single transgene. However, numerous genes associated with athletic ability may be potential gene-doping material. Here, we developed a detection method that targets multiple transgenes. We targeted 12 genes that may be associated with athletic performance and designed two TaqMan prob...
[Antidoping rules in equine sports and pharmacological aspects of rule-consistent medical treatment and feeding of sport horses].
Tierarztliche Praxis. Ausgabe G, Grosstiere/Nutztiere    April 23, 2020   Volume 48, Issue 2 106-117 doi: 10.1055/a-1128-4286
Hertzsch R.Veterinarians play an essential role in the prevention of doping in equine sports, both as attending clinicians as well as official competition veterinarians. This complex task requires comprehensive knowledge concerning the pertinent regulations. These include official laws, such as the animal protection and medicines laws as as well as rules issued by the responsible equine sports authority. Furthermore, veterinarians are required to determine adequate withdrawal times following the legitimate use of medications in sport horses. This may be performed by applying appropriate data published by...
Identification of ex vivo catabolites of peptides with doping potential in equine plasma by HILIC-HRMS.
Drug testing and analysis    March 24, 2020   Volume 12, Issue 6 771-784 doi: 10.1002/dta.2781
Guan F, Fay S, Li X, You Y, Robinson MA.Bioactive peptides pose a great threat to sports integrity. The detection of these peptides is essential for enforcing their prohibition in sports. Identifying the catabolites of these peptides that are formed ex vivo in plasma may improve their detection. In the present study, the stability of 27 bioactive peptides with protection at both termini in equine plasma was examined under different incubation conditions, using HILIC coupled to HRMS. Of the 27 peptides, 13 were stable after incubation at 37°C for 72 hr, but the remaining 14 were less stable. Ex vivo catabolites of these 14 peptides ...
Detection of intra-articular gene therapy in horses using quantitative real time PCR in synovial fluid and plasma.
Drug testing and analysis    March 16, 2020   Volume 12, Issue 6 743-751 doi: 10.1002/dta.2785
Haughan J, Jiang Z, Stefanovski D, Moss KL, Ortved KF, Robinson MA.Gene therapy promotes the expression of missing or defective genes and can be curative following administration of a single dose. Gene therapy is prohibited in equine athletes by regulatory bodies due to the high potential for abuse and novel analytical methods are needed for detection. The goal of this study was to detect the administration of an experimental gene therapy: a recombinant adeno-associated viral vector (rAAV) carrying a transgene for the anti-inflammatory cytokine IL-10 (rAAV-IL10). Twelve horses were randomly assigned to receive an intra-articular injection of rAAV-IL10 or phos...
Label-free Proteomics for Discovering Biomarker Candidates for Controlling Krypton Misuse in Castrated Horses (Geldings).
Journal of proteome research    February 25, 2020   Volume 19, Issue 3 1196-1208 doi: 10.1021/acs.jproteome.9b00724
Wong KS, Cheung HW, Choi TLS, Kwok WH, Curl P, Mechie SC, Prabhu A, Wan TSM, Ho ENM.Recent advances in label-free quantitative proteomics may support its application in identifying and monitoring biomarkers for the purpose of doping control in equine sports. In this study, we developed a workflow of label-free quantitative proteomics to propose plasma protein biomarkers in horses after administration with krypton (Kr), a potential erythropoiesis-stimulating agent. Plasma proteomes were profiled by using nanoliquid chromatography-high-resolution mass spectrometry. An in-house mass spectral library consisting of 1121 proteins was compiled using samples collected from geldings (...
Using Inductively Coupled Plasma Mass Spectrometry to Assess Essential and Performance-Enhancing Metals in the Urine of Racehorses.
Journal of analytical toxicology    February 6, 2020   Volume 44, Issue 5 490-498 doi: 10.1093/jat/bkaa004
Karakka Kal AK, Perwad Z, K Karatt T, Nalakath J, Subhahar M.Recently, an increased tendency to use various metals has been observed in the sports competition fields. Many of these metals and their organic complexes reportedly have good pharmacologic, therapeutic and performance-enhancement uses; they are banned or recommended as controlled medications in competitive sports. The objective of this research was to determine the concentration of pharmacologically relevant metals in urine samples collected from racehorses at various sport events, develop a method and assess the concentrations of above metals using inductively coupled plasma mass spectrometr...
In vivo metabolism of the designer anabolic steroid hemapolin in the thoroughbred horse.
Drug testing and analysis    February 4, 2020   Volume 12, Issue 6 752-762 doi: 10.1002/dta.2769
Waller CC, Weththasinghe SA, McClure L, Cawley AT, Suann C, Suann E, Sutherland E, Cooper E, Heather A, McLeod MD.Hemapolin (2α,3α-epithio-17α-methyl-5α-androstan-17β-ol) is a designer steroid that is an ingredient in several "dietary" and "nutritional" supplements available online. As an unusual chemical modification to the steroid A-ring could allow this compound to pass through antidoping screens undetected, the metabolism of hemapolin was investigated by an in vivo equine drug administration study coupled with GC-MS analysis. Following administration of synthetically prepared hemapolin to a thoroughbred horse, madol (17α-methyl-5α-androst-2-en-17β-ol), reduced and dihydroxylated madol (17α-me...
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