Ethical Considerations in the Use of Peptides in Sports

Why sport changes the question

Outside organized sport, deciding whether to use a peptide is mostly about personal risk and the law. Our page on the broader ethics of peptide use covers those arguments, and our peptide legal status overview covers the law. Tested sport adds something else: every athlete has signed up to the same rulebook, so one person's choice affects the people they compete against.

That rulebook is broad. As of October 2026, WADA's 2026 Prohibited List names BPC-157 under S0 (non-approved substances) and TB-500 under S2.3 (growth factors). Growth hormone releasers such as CJC-1295 and ipamorelin sit under S2.2.4, and MOTS-c is named under S4.4.1. All of them are banned in and out of competition. Semaglutide and tirzepatide are only in WADA's Monitoring Program, so labs track them but athletes aren't sanctioned. Our page on competitive sports rules has the full placements and the college and pro league rules.

Fairness to rivals

The standard case against doping is about fairness. Athletes in a tested sport agree to compete without certain substances, and someone who uses them in secret gets an edge over everyone who kept that agreement. The Stanford Encyclopedia of Philosophy's entry on human enhancement adds that the edge pushes others toward the same drugs and favors athletes who can afford them.

Not every ethicist accepts the "level playing field" framing. Bengt Kayser and two colleagues argued in a 2007 BMC Medical Ethics paper that sport was never level to begin with. Their example was the Finnish skier Eero Mäntyranta, whose inherited erythropoietin receptor mutation gave him unusually high hemoglobin. He won three Olympic golds in 1964. They proposed medically supervised enhancement in place of outright bans.

The usual reply is that unequal genes and a broken agreement are different problems. Nobody chose their erythropoietin receptor. An athlete who uses a banned peptide chose to break a rule their rivals are keeping, whatever one thinks of the rule itself. That's why the fairness argument is strongest in tested sport and much weaker in untested lifting, where no such agreement exists.

Healing or enhancing

Many athletes see recovery peptides differently from growth hormone releasers. The common reasoning is that BPC-157 or TB-500 for a sore tendon only restores normal function, while GH secretagogues push the body past its baseline. The sport-specific problem is that getting back on the field sooner is itself a competitive advantage.

Kayser and colleagues note that the line is blurred even in accepted medicine. They cite elbow ligament surgery in baseball pitchers, which anecdotally leaves some throwing better than before the injury. Nobody calls that cheating.

WADA doesn't use the healing-versus-enhancing line for these compounds. S0 turns on approval status: it covers any substance "with no current approval by any governmental regulatory health authority for human therapeutic use," whatever the reason someone takes it. Every S0 substance is Specified, and the list's introduction says Specified substances "should not in any way be considered less important or less dangerous" than others. A Therapeutic Use Exemption exists for medical need, but in our reading it assumes an approved treatment, which unapproved peptides don't have.

Health risk to the athlete

Under Article 4.3.1 of the World Anti-Doping Code, WADA can list a substance that meets two of three criteria. One is evidence that it enhances performance or could. Another is an actual or potential health risk. The last is WADA's judgment that its use violates the spirit of sport.

For peptides, the health argument rests mostly on what nobody knows. A 2025 systematic review of BPC-157 in orthopaedic sports medicine (HSS Journal) found consistent healing effects in animal models but concluded that "in-human safety remains unknown." No animal study it found had tracked adverse events beyond 6 weeks. The review also notes that athletes' use is growing.

Product quality adds another layer. In an April 2026 advisory, Health Canada named BPC-157 and TB-500 among the unauthorized injectable peptides it had seized. It warned that such products may hold the wrong amount of active ingredient, or none at all, and may carry contaminants such as endotoxins.

Kayser and colleagues push back here too. They argue that bans drive use underground, which makes it riskier, and that supervision would protect athletes better than prohibition. Defenders of the list answer that even supervised use would push clean athletes toward drug risks they'd rather avoid, and those athletes deserve protection too.

Pressure from rivals and teams

In 1983 the bioethicist Thomas Murray titled a Hastings Center Report essay "The Coercive Power of Drugs in Sports." The coercion argument holds that once some competitors use a drug, an athlete who abstains is no longer choosing freely. The real choice becomes one between their health and their chance to compete. In team sport, the pressure can come from the organization itself.

The Essendon case in Australian football shows how. In early 2012, players signed consent forms at a meeting with sports scientist Stephen Dank and then received injections through the club's supplements program, according to ABC News's account of the Court of Arbitration for Sport (CAS) award. Players were told to keep the injections secret, and the club doctor was kept out of the loop. In January 2016, CAS found the players had used thymosin beta-4 and banned 34 current and former players for two years. The bans were backdated but still kept them out of the 2016 season.

The people who designed that program held the power, yet the players carried the sanction. CAS found by a majority that every player was significantly at fault: none asked the club doctor about the injections, and none who was tested that season disclosed them on a doping control form. The Code does let anti-doping bodies pursue support staff separately for administration and complicity. Our page on peptide legal cases covers Essendon in more detail.

Strict liability

Strict liability is why Essendon ended the way it did. Article 2.1.1 of the Code calls it each athlete's "personal duty to ensure that no Prohibited Substance enters their bodies." An anti-doping body doesn't have to prove the athlete meant to dope, or even knew, to establish a violation.

Intent still matters for the length of a ban. Under the 2021 Code, in force through December 2026, a positive for a non-Specified substance such as TB-500 carries four years unless the athlete shows it wasn't intentional. For a Specified substance such as BPC-157, the ban is two years unless the anti-doping organization proves intent. The 2027 Code, in force from January 1, 2027, reworks these tiers, adding a three-year ban for some non-Specified cases where the use was unrelated to sport performance.

Defenders say strict liability is the only workable rule. If "I didn't know" were a defense, nearly every case would turn on claims nobody can check. Critics answer that with gray-market peptides the rule bites hard. A vial labeled as one compound may contain another, so an athlete can be sanctioned for a substance they never knowingly took. Our page on peptide sourcing and quality control explains why labels are unreliable.

The spirit of sport

The third criterion is the most argued over. The 2021 Code defines the spirit of sport as "the ethical pursuit of human excellence through the dedicated perfection of each Athlete's natural talents." The 2027 Code swaps in "athletic excellence." The Stanford entry traces the idea partly to Murray's view that the "virtuous perfection of natural talents" is the point of sport.

Critics call the criterion vague. Kayser and colleagues argue it rests on an essentialist view that sport tests natural capacities, when sport has always relied on technology. For peptides the debate has a concrete edge. Because S0 is triggered by missing approval, WADA can ban a compound like BPC-157 without human evidence that it improves performance, leaning on health risk and the spirit of sport instead. Supporters call that reasonable caution with untested drugs. Critics call it a ban built on speculation.

The approval test also produces odd edges. Melanotan II isn't named on the list, but as an unapproved substance it falls under S0 by default. GHK-Cu isn't named either, and we couldn't confirm how WADA treats it. Bremelanotide (PT-141) and elamipretide (SS-31) are now approved prescription medicines in the US, so S0 no longer clearly covers them. As of October 2026, we couldn't confirm whether another section does.

What we still don't know

• How many tested athletes use peptides. We found no reliable prevalence data, so claims that "everyone is using" rest on anecdote.
• Whether the 2027 list changes behavior. USADA says its S0 text names "peptides" in general, amid a "striking upward trend" in peptide use.
• How the 2027 Code's new sanction tiers will treat athletes who test positive after using a mislabeled peptide.
• Whether WADA moves semaglutide or tirzepatide onto the list. Both stay in the 2027 Monitoring Program.