Ibutamoren

Ibutamoren is a non-peptide growth hormone secretagogue that stimulates the secretion of growth hormone and IGF-1. Ibutamoren is not currently approved for medical use, such as in cases of growth hormone deficiency.

Doping Relevance

Due to the stimulation of growth hormone release following administration of ibutamoren, the substance is considered relevant to doping.

The possibility of the misuse of growth hormone secretagogues (including ibutamoren) in sports was already highlighted in 2006 and 2007 in publications by Mario Thevis et al. [1, 2].

Growth hormone secretagogues were first specifically listed by name on the World Anti-Doping Agency (WADA) Prohibited List in 2015 under the designation GHS (growth hormone secretagogues), with the ghrelin mimetics anamorelin, ipamorelin, and tabimorelin cited as examples. Although ibutamoren is not listed by name, it is classified by WADA as a related compound with effects similar to those of the growth hormone secretagogue group and is therefore prohibited.

Detection of Doping and Doping Cases

Ibutamoren can be detected using mass spectrometric methods on urine samples [3, 4], taking into account that ibutamoren is extensively metabolized and hydroxylated metabolites can be identified [3].

According to statistics from WADA-accredited laboratories worldwide, 2 positive test results
for ibutamoren were reported in 2015, 4 in 2016, and 11 in 2017.

References

[1] Thevis, M., Wilkens, F., Geyer, H., Schänzer, W. Determination of therapeutics with growth-hormone secretagogue activity in human urine for doping control purposes. Rapid Commun. Mass Spectrom. 20 (2006) 3393–3402
Abstract

[2] Thevis M, Schänzer W Emerging Drugs - Potential for misuse in sport and doping control detection strategies Mini-Reviews in Medicinal Chemistry, 7 (2007) 533–539
Abstract

[3] Sobolevsky T, Prasolov I, Rodchenkov G: Urinary metabolism of ibutamoren, a small-molecule growth hormone secretagogue. In: Schänzer W, Thevis M, Geyer H, Mareck U (eds.). Recent advances in doping analysis (21). Sportverlag Strauß, Cologne (2013), 182–186
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[4] Thevis M, Schänzer W. Analytical approaches for the detection of emerging therapeutics and non-approved drugs in human doping controls. J Pharm Biomed Anal. 2014, 101:66-83
Abstract