Rugby league player receives sanction

  • Doping Violation Update

Sport Integrity Australia acknowledges the decision of the National Rugby League (NRL) to sanction athlete Michael Jennings for the presence of prohibited substances and their metabolites and the use of prohibited substances.

Mr Jennings returned an Adverse Analytical Finding (AAF) from an out-of-competition doping control test on 21 September 2020.

His sample detected the presence of LGD-4033 (Ligandrol) and its metabolite Di-hydroxy-LGD-4033 and Ibutamoren and its metabolites Desbenzyl Ibutamoren and OH Ibutamoren.

It was determined that Mr Jennings had committed the anti-doping rule violations of presence and use of prohibited substances.

LGD-4033 (Ligandrol) is listed under Class S1 (Anabolic Agents) and Ibutamoren is listed under Class S2 (Peptide Hormones, Growth Factors, Related Substances, and Mimetics) of the Prohibited List. Both LGD-4033 (Ligandrol) and Ibutamoren are prohibited at all times.

The NRL imposed a three (3) year ban on Mr Jennings commencing on 21 September 2020.

Mr Jennings will be eligible to return to competition on 21 September 2023.


LGD-4033 is promoted as a selective non-steroidal anabolic agent. It is claimed to be a substance that induces muscle (and bone) growth without the side effects associated with steroid use. However, information on the safety of LGD-4033 is scarce due to a lack of medium and long-term clinical trials - hence the medium and long-term health impacts are unknown.

It should be noted that a number of Selective Androgen Receptor Modulators (SARMs) have associated health-risks, particularly for the heart and liver.

There are a number of health concerns for substances listed under Class S2 (Peptide Hormones, Growth Factors and Related Substances, and Mimetics). Long-term studies in the use of growth hormone releasing peptides (GHRPs) have not been performed as the majority available on the internet have not been approved for human use. As such, they are considered a Schedule 10 poison and are prohibited to sell, supply and use.

Sport Integrity Australia is committed to protecting the right of clean athletes to fair competition.

If you are aware of any suspicious doping activity, you can: 

Sport Integrity Australia recommends athletes check substances and medications before taking them and to follow our advice on any supplements

The Sport Integrity app provides a useful resource for athletes and support staff to check substances and medications. Additionally, it provides information on how to find batch-tested supplements or see if a Therapeutic Use Exemption (TUE) is required.

The Sport Integrity app is available for free download via the App Store and on Google Play

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