WADA Prohibited List and research peptides: how BPC-157 and TB-500 are classified and detected
Prepared by: Research Desk. Sources are linked for verification.
Published 23 October 2026
At a glance
- Primary record: the World Anti-Doping Agency (WADA) Prohibited List, updated annually and in force at all times (in and out of competition) for categories S0 and S2
- Compounds covered: BPC-157 (listed explicitly under S0 since 2022) and thymosin beta-4 and its derivatives such as TB-500 (listed under S2.3)
- Analytical literature: high-resolution liquid chromatography–mass spectrometry (UHPLC-HRMS) methods published between 2022 and 2026 track parent peptides and cleavage metabolites in urine and dried blood matrices
- US regulatory status: neither BPC-157 nor TB-500 is an FDA-approved drug; both appear on FDA's safety-risk page and on the July 2026 Pharmacy Compounding Advisory Committee agenda
How the WADA Prohibited List categorises research peptides
Anti-doping rules do not wait for a compound to receive marketing authorisation from a medicine regulator. Instead, the WADA Prohibited List captures experimental and research-grade peptides through two overlapping categories that apply both in competition and out of competition:
- Category S0 (Non-Approved Substances). This catch-all category covers any pharmacological substance that is not addressed by another section of the List and has no current approval by any governmental regulatory health authority for human therapeutic use. That includes compounds in preclinical or clinical development, discontinued drug candidates and designer or research-only peptides. Starting with the 2022 Prohibited List, WADA added BPC-157 by name as an explicit example under Category S0 so that athletes and support personnel could find it in a text search of the document.
- Category S2 (Peptide Hormones, Growth Factors, Related Substances, and Mimetics). Section S2.2 covers growth hormone releasing peptides (GHRPs), growth hormone secretagogues and releasing factors such as CJC-1295, ipamorelin, hexarelin, tabimorelin and tesamorelin. Section S2.3 covers growth factors and growth factor modulators affecting muscle, tendon or ligament protein synthesis and vascularisation, and explicitly names thymosin-beta4 and its derivatives, giving TB-500 as an example.
Because both S0 and S2 are "at all times" categories, anti-doping laboratories screen for these peptides in out-of-competition urine and blood samples as well as race-day or event-day samples.
How anti-doping laboratories detect BPC-157 and TB-500
Short linear peptides are cleaved rapidly by peptidases in blood and tissues, which means that the intact parent peptide may appear in urine only briefly after administration in animal or in-vitro models. Analytical chemists working in anti-doping control therefore map stable breakdown fragments (metabolites) and screen for both the intact chain and its diagnostic fragments.
| Compound | Sequence / structure | Key analytical papers | Matrices studied |
|---|---|---|---|
| BPC-157 | 15-residue linear peptide (GEPPPGKPADDAGLV) | He et al., 2022, PubMed; awan / stable-isotope study, 2023, PubMed | Rat and dog plasma/urine; human liver microsomes and S9 fractions |
| TB-500 (thymosin beta-4 fragment) | N-acetylated heptapeptide Ac-LKKTETQ (or 43-residue parent) | Quantification and metabolite study, 2024, PubMed; Equine population study, 2025, PubMed | In-vitro incubations, rat biological matrices, equine plasma/urine |
| Multi-peptide panels | Peptidic and non-peptidic doping agents | Harmonized blood workflow, 2026, PubMed | Dried blood spots (DBS) and liquid blood |
BPC-157 metabolism and mass spectrometry
In a 2022 preclinical pharmacokinetic study in rats and dogs (He et al., 2022, PubMed), researchers reported that intact BPC-157 had a short elimination half-life and was degraded into shorter peptide fragments and constituent amino acids. Building on that challenge, a 2023 study in Molecules (PubMed) used stable-isotope labelling combined with ultra-high-performance liquid chromatography and high-resolution mass spectrometry (UHPLC-HRMS) to characterise the in-vitro metabolic profile of BPC-157 for doping control, identifying characteristic N- and C-terminal truncation products that extend the detection window.
TB-500 and thymosin beta-4 fragments
The name TB-500 is used in research catalogues both for the full 43-residue protein thymosin beta-4 and for its synthetic N-acetylated active-site heptapeptide fragment, Ac-Leu-Lys-Lys-Thr-Glu-Thr-Gln (Ac-LKKTETQ). A 2024 analytical paper in the Journal of Chromatography B (PubMed) validated a UHPLC-Q-Exactive Orbitrap tandem mass spectrometry method to quantify TB-500 alongside its cleavage metabolites in in-vitro assays and in rats. In 2025, a study in Drug Testing and Analysis (PubMed) reported a population baseline and detection strategy for thymosin beta-4 in equine doping control.
More recently, a July 2026 paper in The Analyst (PubMed) described a rapid, harmonized extraction and mass-spectrometry workflow that screens both peptidic and non-peptidic doping agents in dried blood spots and liquid blood matrices.
How sport listings differ from medicine regulation
A listing on the WADA Prohibited List is a sport-governance rule, not a drug-approval record or a clinical trial finding:
- WADA's criteria. Under the World Anti-Doping Code, a substance is considered for the Prohibited List if it meets at least two of three criteria: potential to enhance sport performance, actual or potential health risk to the athlete, or violation of the spirit of sport. For Category S0, the absence of regulatory approval for human therapeutic use is sufficient to place a pharmacologically active substance off-limits in tested sport.
- FDA's records. In the United States, FDA evaluates bulk drug substances nominated for pharmacy compounding under section 503A. As covered in our report on the July 2026 FDA compounding committee, both BPC-157 and TB-500 were placed on the 23 July 2026 advisory committee agenda, and both appear on FDA's page of bulk drug substances that may present significant safety risks among withdrawn Category 2 nominations.
For how to distinguish sport rules, advisory committee agendas and peer-reviewed trials, see our guide on how to read a research or regulatory signal.
Limitations of the evidence
- Analytical doping-control papers establish how laboratories detect a compound and its metabolites in biological samples; they do not evaluate clinical safety or efficacy in humans.
- Metabolic profiles generated in human liver microsomes, rat plasma or equine samples may not match human in-vivo urinary excretion kinetics in every detail.
- Catalogue products sold as TB-500 may contain either the 7-residue fragment Ac-LKKTETQ or the 43-residue thymosin beta-4 sequence, so analytical studies specify the exact molecular mass and sequence tested.
Key terms
- Category S0. The section of the WADA Prohibited List covering pharmacologically active substances with no current governmental regulatory approval for human therapeutic use.
- Category S2. The section covering peptide hormones, growth factors, related substances and mimetics.
- UHPLC-HRMS. Ultra-high-performance liquid chromatography coupled to high-resolution mass spectrometry, used to separate and identify peptides and their breakdown fragments by exact mass-to-charge ratio.
- Dried blood spot (DBS). A sampling method in which small drops of blood are dried on filter paper for transport and mass-spectrometric analysis.
Where researchers source it
Purita is a store that lists BPC-157 for laboratory research use only. Its product page labels the item for research use only and not for human or animal administration.
Affiliate disclosure: this is a paid link. KlowSignal earns a commission if a purchase is made through it, at no extra cost to the buyer. A listing is not an endorsement or a statement about product quality. See the affiliate disclosure.
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