The sorry tale of the Essendon Football Club drug saga reached a new low last Tuesday as 34 past and present players were handed year-long suspensions for the use of the banned peptide thymosin-beta 4 (Tβ4).

The terms ‘peptide’ and Tβ4 have been circulated and trumpeted to the point of exhaustion by the media circus and couch-experts alike. And yet, ironically, there has been little regard to what they actually are and do.

On the most basic level, a peptide is essentially a small protein. Billions of unique peptides exist, all with different effects and functions in the body. Physiological examples include insulin, oxytocin, and casein, the main protein in milk. Thus, to taunt Essendon supporters for the use of “peptides” is rather non-specific. A much more intelligent insult would be to focus on the administration of thymosin beta-4.

Thymosin beta-4 is a naturally occurring peptide, and is found ubiquitously in our cells. A range of studies on animal models have indicated several key biological activities for Tβ4, such as “promot[ing] wound repair, tissue protection, and regeneration in the skin, eye, heart and central nervous system”. Only a handful of clinical trials in humans have attempted to explore these roles practically.

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There have been encouraging results for the use of Tβ4 as a topical gel to treat venous stasis ulcers, a type of wound that develops on the lower leg of patients with chronic vascular disease. Two other reports indicated that Tβ4, formulated in eye-drops, may enhance corneal wound healing in diabetic patients, and improve ocular discomfort. These are the most advanced trials to date. As of yet, despite promising animal models, there has been no significant study exploring the efficacy of intravenous Tβ4 injections in treating ischemic heart injury.

This current literature is notable for its apparent irrelevancy to an AFL footballer. It begs the question; did Tβ4 make a difference to the Essendon players? The only honest answer is that we don’t know. Most of our understanding exists on a molecular and cellular level, without any significant appreciation of how Tβ4 influences applicable outcomes such as exercise performance, endurance, muscle strength, and time to recovery. Furthermore, as the majority of research has been performed on mice, rat and pig models, any results are not directly translatable to a human, let alone an elite athlete. This is a stark contrast to a supplement such as EPO, which has been investigated thoroughly.

Despite this, Tβ4’s place on the banned-substances list is warranted. It reflects the possibility that the effects of the supplement may manifest as a tangible improvement in athletes. However, any time a journalist flippantly declares it “heals damaged tissue and speeds recovery”, it should be noted that such claims are a harmful distortion of the facts.

Ultimately, this lack of literature on the drug best serves to illustrate the recklessness of Stephen Dank in committing to something so experimental in nature. Perhaps he was privy to anecdotal evidence the rest of us weren’t. The drug has been used by amateur athletes and bodybuilders, and reportedly in the equine industry. Nevertheless, any benefits are unsubstantiated, which lends to an exasperation shared by supporters as to why Dank would risk so much for a substance that potentially offers no advantage at all. As a supporter, I would have much preferred a drug that allowed us to hit a target inside 50.

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Fortunately for the players, despite the appending doom touted by the media, the current research suggests Tβ4 is safe. 23 non-clinical toxicology studies have been performed “that demonstrate the safety of Tβ4 for its current and planned uses in man”. Significantly, a human clinical trial in healthy volunteers found “intravenous administration of Tβ4 appears to be safe and well-tolerated by all subjects with no dose limiting toxicity or serious adverse events reported”. Admittedly, this trial is limited in that it only followed subjects for a period of 28 days, and thus there is a need for further research if Tβ4 is ever to be developed as a medication.

In the end, despite three years of intense scrutiny, the drug at the centre of the investigation remains poorly understood. In this regard, it could serve as a reflection of the whole ordeal. Everyone has an opinion, often voiced with authority and conviction. The reality is that much of this complex narrative continues to be a mystery. Many would have been well served by the humble words of the Socratic paradox – “I know that I know nothing”.

Disclaimer: This is not a reflection on the merit of the recent verdict, which requires a separate, more nuanced debate.

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