When an Athlete Tests Positive for a Peptide

On 5 December 2014, doping control officers from UK Anti-Doping turned up at a Leigh Centurions training session and collected an out-of-competition urine sample from the prop forward Jamie Acton. The laboratory analysed it and found nothing prohibited, and at UKAD's instruction it went into long-term storage. On 5 February 2021 UKAD asked the laboratory to take it out and run a retrospective analysis for growth hormone-releasing peptides. This time the report came back with adverse analytical findings for GHRP-6 and for one of its breakdown products. Acton received a two-year ban, deemed to run from 30 April 2021 to 29 April 2023. It was the first UKAD case in which a sample had been found positive after re-analysis following long-term storage 1.

What happens when an athlete tests positive for a peptide? A laboratory reports that a prohibited substance or its metabolite is present in a sample, the athlete is notified, and a legal process begins in which the finding itself is close to decisive and almost everything else goes to the length of the sanction. What the finding proves is narrow: that the substance was in that sample. Just as instructive is how many peptide cases never involve a positive test. The analytical chemistry of detection is a subject in its own right, covered elsewhere on this site. This piece follows three public, adjudicated cases to see how a peptide violation is actually established, and what a sanction does and does not tell anyone watching.

From a sample to a sanction

The route from a finding to a ban is procedural and fairly standard across sports. A sample is split at collection into two sealed parts. If the laboratory reports an adverse analytical finding in the first, the anti-doping organisation reviews it, notifies the athlete, and the athlete can ask for the second part to be analysed. If a charge follows, the athlete can accept the proposed sanction or contest it before an independent hearing body, and decisions can ultimately be appealed to the Court of Arbitration for Sport 6. Most cases end with the athlete accepting, which is why most of them are short press releases rather than long judgments.

Underneath the procedure sits the principle that shapes everything: strict liability. Each athlete is responsible for any prohibited substance found in their sample, and a violation is established by its presence regardless of whether the athlete used it intentionally, carelessly or unknowingly 5. An athlete's explanation, whether a contaminated supplement, a doctor's advice or a mistake, does not change whether a violation happened. It can change the consequences, sometimes substantially.

What an adverse finding proves, and what it does not

Read the Acton case closely and the limits of a finding come into focus. The laboratory report established that GHRP-6 and a breakdown product of it were present in a urine sample collected on a particular day in 2014 1. That is what an adverse analytical finding is: a statement about the contents of a container, backed by a validated method and a chain of custody. Everything else in the public account concerns process: when the sample was collected, when it was re-analysed, and when the ban runs.

A finding cannot say, and does not try to say, why the substance was there, whether it improved anyone's performance, how much was taken or over what period. Those questions matter to the sanction and are argued out in hearings where there is a hearing. They do not decide whether a violation took place. Spectators tend to read a positive test as proof of cheating and a clean test as proof of innocence, and the Acton case undermines both readings. A clean result in 2014 was not innocence; it was the limit of what anyone was then looking for.

The freezer as a time machine

The more interesting feature of the case is the storage. Anti-doping laboratories keep selected samples in secure long-term storage so they can be re-examined when methods improve or when new intelligence points to a substance nobody had been looking for 1. A sample is therefore not a single test at a single moment. It is an open question that can be asked again with better instruments years after the athlete has forgotten giving it.

For peptides this matters more than for most substance classes, because the list of compounds laboratories look for has grown so quickly. A sequence that circulated unseen in one season can be targeted a few seasons later, and the archive of stored samples becomes a record waiting to be read. The deterrent logic is plain: the relevant test is not the one that exists on the day the sample is given but the one that will exist when it is next taken out of storage. UKAD described Acton's case as a first of its kind 1. It was not presented as a one-off.

The case with no positive test

The most famous peptide case in the history of sport began with no positive test at all. During the 2012 season, players at the Essendon Football Club in the Australian Football League took part in a club supplements programme. The anti-doping authorities alleged that the programme included injections of thymosin beta-4, a prohibited peptide. In March 2015 the AFL's anti-doping tribunal found the charges against thirty-four current and former players not proven. The World Anti-Doping Agency appealed to the Court of Arbitration for Sport 2.

On 11 January 2016 the CAS panel upheld the appeal. It said it was comfortably satisfied, the anti-doping standard of proof, higher than the balance of probabilities but lower than proof beyond reasonable doubt, that the players had used thymosin beta-4. Each received a two-year period of ineligibility backdated to 31 March 2015, with credit for time already served, which in practice kept most out for the 2016 season 2. The case turned on how circumstantial evidence should be weighed. The tribunal had treated it as links in a chain, where each link must hold; the CAS panel treated it as strands in a cable, where individually weak strands can together bear the load 2.

For anyone who equates doping with a failed test, the case is unsettling, and it was meant to be. It established, very publicly, that a peptide violation can be proved from documents, testimony and circumstance, without any sample ever showing anything. The test is one route to a sanction, and not always the main one.

The confession

The third route is the simplest, and the newest cases increasingly take it. BPC-157 was not prohibited before 2022. That year it was added by name to the Prohibited List in the category for non-approved substances, those with no current approval for therapeutic use in people. Because it has no approved medical use, no therapeutic use exemption can be granted for it 3. Its naming came as the compound's popularity grew, not as the result of any new human evidence about it.

In August 2024 the US Anti-Doping Agency announced that an independent arbitrator had imposed a one-year sanction, beginning on 10 April 2024, on the speedskater Kamryn Lute. She had used a supplement containing BPC-157 that had been recommended by a medical provider. She never tested positive for it or for any other prohibited substance. She declared the use and admitted it during the agency's investigation 4. The violation was established by her own account.

Why the list keeps growing

Set side by side, the three cases trace the history of the list itself. GHRP-6 belongs to a family of growth hormone-releasing peptides that the Prohibited List has long named as a class. Thymosin beta-4 was caught by broad wording about growth factors and substances with similar effects. BPC-157 was added explicitly once it became too common to leave to general wording. The list is revised every year, and a substance usually appears on it by name only after it has appeared in gyms, clinics and case files 7.

That lag is not a failure. It is how the list is built: it follows the market. The same research peptides that trend on social media turn up a season or two later in anti-doping intelligence, and then in the annual revision. A peptide's appearance on the list is often the first formal acknowledgement by any public body that people outside a laboratory are using it.

What a sanction does not tell you

One more misreading is worth correcting, because it runs in the opposite direction. A substance on the Prohibited List is not thereby shown to work. Inclusion is a judgement about potential for performance enhancement, risk to health and the spirit of sport, made by an organisation that has to act before the evidence is in 7. Plenty of listed substances have no convincing evidence of improving anyone's performance. They are listed because they might, because they are unassessed, or because allowing them would make the rules unenforceable. An athlete banned for a peptide has been found to have broken a rule. Nobody has found that the peptide did anything.

That is where a piece about cases has to stop. Behind each adverse finding sit questions this account deliberately leaves alone: how the method was validated, what the reference material was, how the laboratory established that a metabolite belonged to the parent compound, and how long after use such a finding remains possible. They are questions for the analytical chemist and the expert witness. The public record answers something simpler and still worth knowing: a peptide case can begin in a freezer, in a filing cabinet or in an interview room, and only sometimes at the moment a sample is tested.