Peptides Banned by WADA: What the 2025 Prohibited List Actually Says

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Peptides Banned by WADA: What the 2025 Prohibited List Actually Says

Every year, the World Anti-Doping Agency (WADA) publishes its Prohibited List — a comprehensive document outlining every substance and method banned in competitive sport. For athletes, coaches, and researchers, understanding which peptides appear on this list, and why, is essential. This article breaks down the key peptide categories prohibited by WADA, drawing directly from the 2025 Prohibited List, which came into effect on 1 January 2025.

What Is the WADA Prohibited List?

The WADA Prohibited List is updated annually and comes into effect on 1 January each year. It is the global standard for anti-doping in sport, adopted by all signatories to the World Anti-Doping Code, including international federations, national anti-doping organisations, and the International Olympic Committee.

Substances are added to the Prohibited List if they meet at least two of the following three criteria:

  • They have the potential to enhance sport performance
  • They represent an actual or potential health risk to the athlete
  • They violate the spirit of sport

Peptides appear across several sections of the 2025 Prohibited List, primarily due to their performance-enhancing potential.

Section S1: Anabolic Agents

While this section is primarily associated with anabolic steroids, certain peptide hormones with anabolic properties fall under related categories. Selective Androgen Receptor Modulators (SARMs), though not peptides in the traditional sense, are listed here and are often discussed alongside peptide research.

Section S2: Peptide Hormones, Growth Factors, Related Substances and Mimetics

This is the most relevant section for peptides in the 2025 list. WADA prohibits the following categories under S2:

Erythropoiesis-Stimulating Agents (ESAs)

These include erythropoietin (EPO) and its analogues. EPO is a peptide hormone produced naturally by the kidneys that stimulates red blood cell production. Synthetic versions and analogues — including darbepoetin alfa, methoxy polyethylene glycol-epoetin beta, and biosimilar EPO compounds — are all prohibited.

Peptide Hormones and Their Releasing Factors

The 2025 list explicitly prohibits:

  • Growth Hormone (GH) and its fragments and releasing factors, including Growth Hormone Releasing Hormone (GHRH) and its analogues such as CJC-1295 and sermorelin
  • Growth Hormone Releasing Peptides (GHRPs) including GHRP-1, GHRP-2, GHRP-3, GHRP-4, GHRP-5, GHRP-6, and hexarelin
  • Ghrelin and ghrelin mimetics, including ipamorelin and anamorelin
  • Insulin-like Growth Factors (IGFs), including IGF-1 and all its analogues
  • Insulin and all insulin analogues
  • Chorionic Gonadotrophin (CG) and Luteinising Hormone (LH) and their releasing factors, including gonadorelin, buserelin, deslorelin, leuprorelin, nafarelin, and triptorelin
  • Corticotrophins and their releasing factors

Growth Factors and Growth Factor Modulators

WADA's 2025 list prohibits growth factors that affect muscle, tendon, or ligament protein synthesis, vascularisation, energy utilisation, or regenerative capacity. This includes:

  • Fibroblast Growth Factors (FGFs)
  • Hepatocyte Growth Factor (HGF)
  • Mechano Growth Factors (MGFs)
  • Platelet-Derived Growth Factor (PDGF)
  • Vascular Endothelial Growth Factor (VEGF)

Any other growth factor affecting the same systems and not otherwise mentioned is also prohibited under the catch-all provisions of S2.

Section S4: Hormone and Metabolic Modulators

Several peptide-related compounds appear in S4 of the 2025 list, including:

  • Thymosin Beta-4 (TB-500) — prohibited as a metabolic modulator due to its role in tissue repair and potential performance enhancement
  • BPC-157 — peptides with similar mechanisms that modulate healing and recovery fall under the catch-all provisions of S4
  • Melanotan II — a synthetic analogue of alpha-melanocyte-stimulating hormone, prohibited under this section

The S4 catch-all clause covers any substance with a similar chemical structure or biological effect to those listed, meaning novel peptides developed to mimic prohibited compounds are also banned under the 2025 list.

In-Competition vs. Out-of-Competition

It is important to note that some substances on the 2025 Prohibited List are banned at all times (both in and out of competition), while others are only prohibited in-competition.

Most peptide hormones under S2 are prohibited at all times, meaning an athlete cannot use them during training periods either. This is a critical distinction, as some athletes mistakenly believe that out-of-competition use carries no risk — under the 2025 list, it does.

The "Prohibited at All Times" Category

The following peptide-related substances are explicitly prohibited at all times under the 2025 WADA framework:

  • Erythropoiesis-stimulating agents
  • Growth hormone and its releasing factors
  • GHRPs and ghrelin mimetics
  • IGF-1 and analogues
  • Insulin (except for approved therapeutic use exemptions)
  • Thymosin Beta-4

Therapeutic Use Exemptions (TUEs)

Athletes who require a prohibited substance for legitimate medical reasons may apply for a Therapeutic Use Exemption (TUE). For example, an athlete with a diagnosed growth hormone deficiency may be granted a TUE for growth hormone therapy. TUEs must be applied for in advance and approved by the relevant anti-doping authority before the substance is used. The TUE process remains unchanged in 2025.

Why Does WADA Prohibit These Peptides?

The rationale behind prohibiting peptide hormones and their releasing factors centres on their ability to artificially enhance physiological processes that directly impact athletic performance:

  • GH and GHRPs increase muscle mass, reduce body fat, and accelerate recovery
  • EPO and ESAs increase oxygen-carrying capacity, directly improving endurance
  • IGF-1 promotes muscle hypertrophy and accelerates tissue repair
  • TB-500 and BPC-157 may accelerate healing of injuries, allowing athletes to train harder and recover faster

WADA's position is that these advantages go beyond natural human capability and undermine the principle of fair competition.

Research Context

Many of these peptides are the subject of ongoing legitimate scientific research. Institutions and researchers study these compounds to better understand human physiology and develop treatments for conditions such as growth hormone deficiency, muscle wasting diseases, and chronic injuries. The 2025 prohibition applies specifically to use in competitive sport — it does not affect the broader scientific and research landscape.

Staying Up to Date

The Prohibited List is updated annually. Athletes and support personnel are strongly advised to check the current 2025 list at wada-ama.org before using any substance, including supplements, as contamination and mislabelling can also result in a positive test.

WADA also operates the Global DRO (Drug Reference Online) tool, which allows athletes to check the status of specific substances in their sport.

Summary

Under the 2025 WADA Prohibited List, peptides appear across multiple sections, primarily S2 (Peptide Hormones, Growth Factors and Related Substances) and S4 (Hormone and Metabolic Modulators). Key prohibited peptides include growth hormone and its releasing factors, GHRPs, EPO, IGF-1, insulin, TB-500, and Melanotan II. Most are prohibited at all times, not just in competition. Athletes should always consult the current WADA Prohibited List and consider applying for a TUE where medically necessary.

This article is intended for informational and research purposes only. For research-grade peptides supplied to verified researchers and institutions, visit  EuroPeptide