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How testing finds peptides: the published methods

The old belief that peptides are invisible to testing is out of date. Anti-doping laboratories have published urine methods for most of the peptides athletes are offered. This page sets out what those papers did, what they found, and the limits they admit.

Last updated November 3, 2026 · Reviewed by Grey Peptides Editorial Board · ✓ Every claim sourced · No products sold, no seller named

📋 Key takeaways

GH-releasing peptides: urine methods detect GHRPs and their metabolites, some up to two days after a single dose.13

BPC-157: a validated urine method reached 0.1 ng/mL, and BPC-157 stayed stable in urine for at least four days.5

TB-500: detection methods exist in horses, and a long-lived metabolite was found in rats up to 72 hours after dosing.79

Methods are not the whole story. Seized products tell laboratories what to look for, and cases also start from evidence other than a sample.10

On this page

  1. Growth hormone-releasing peptides
  2. GHRH analogues: CJC-1295, sermorelin, tesamorelin
  3. BPC-157
  4. TB-500 and thymosin β4
  5. What the methods cannot tell you
  6. Frequently asked questions
  7. Related on Grey Peptides
  8. Sources

Growth hormone-releasing peptides

The growth hormone-releasing peptides (GHRPs) raise the body's own growth hormone, which is why the established test for injected growth hormone does not catch them.1 Three papers built the urine methods:

  • A screening method (2011). Cologne's laboratory extracted GHRP-1, GHRP-2, GHRP-4, GHRP-5, GHRP-6 and others from urine and detected them by liquid chromatography and mass spectrometry, with limits of detection of 0.2 to 1 ng/mL. Because the metabolism of most targets was unknown, the method focused on the intact peptides, with high-resolution data kept so it could be searched later for metabolites.1
  • GHRP-2 in volunteers (2010). After an intravenous dose in ten male volunteers, unchanged GHRP-2 and its specific metabolite were detected in urine in all ten.2
  • Nasal doses and metabolites (2015). After a nasal dose, GHRP-2 and its metabolites were detected in urine up to 47 hours later; GHRP-6 was mostly excreted unchanged and detected for 23 hours; and metabolites of hexarelin and ipamorelin were still detected after the parent compounds had gone. Each compound was given to one volunteer, so the windows are indicative only.3

GHRH analogues: CJC-1295, sermorelin, tesamorelin

A 2021 study noted that GHRH and its synthetic analogues did not appear to have been found in anti-doping samples, despite admissions and intelligence of their use, probably because of low urine concentrations and limited knowledge of their metabolism. It identified 19 major metabolites of sermorelin, tesamorelin, CJC-1295 and CJC-1295 with DAC in the laboratory, synthesised them as reference materials, and built a method with limits of detection generally at or below 1 ng/mL, the performance WADA requires.4 It was tested in fortified urine, not in people who had taken the drugs (our reading of the abstract).

BPC-157

BPC-157 first reached anti-doping laboratories in confiscated vials. In 2017 a US laboratory showed it forms a stable metabolite in plasma, validated a urine method with a limit of detection of 0.1 ng/mL, and found BPC-157 stable in urine for at least four days; measuring the metabolite alongside the parent improved specificity.5 A 2023 study mapped its metabolism further using stable isotope labelling and high-resolution mass spectrometry, for use in doping control.6 Neither paper measured how long BPC-157 stays detectable after a human dose (our reading of the abstracts).

TB-500 and thymosin β4

TB-500 is a synthetic, acetylated fragment of thymosin β4, not the whole protein; see TB-500 is not thymosin beta-4.

  • Horses (2012). The Hong Kong Jockey Club's laboratory detected acetylated LKKTETQ, the key ingredient of TB-500, and its metabolites in horses given a single dose, at 0.01 ng/mL in urine and 0.02 ng/mL in plasma.7
  • Identification (2012). A Belgian laboratory identified the acetylated 17-23 fragment in a TB-500 product, synthesised it, and set out a strategy for detecting it in plasma and urine.8
  • Rats (2024). In rats, the metabolite Ac-LK was the most abundant in the first six hours, and Ac-LKK was a long-term metabolite detected up to 72 hours.9

None of these is a human excretion study, so how long TB-500 can be detected in a person is not established in this literature (our reading).

What the methods cannot tell you

  • No safe window. The detection windows above come from single doses in one or a few people, animals or test tubes. They are not a guide to timing, and laboratories can re-examine stored data for metabolites identified later.13
  • Seizures guide testing. Norway's doping control laboratory found peptide- and protein-based substances in 28% of black-market products seized in 2011 to 2014; its authors describe analysing seized products as a way to predict what will turn up in athletes' urine, and for anabolic steroids the two matched.10
  • Cases do not need a positive test. Our drug-testing guide covers sanction cases built on declarations, tips and products.
  • The product may not be what it says. A vial or supplement can contain something else that is prohibited; see contaminated supplements and products.

Frequently asked questions

Can a drug test detect BPC-157?

A validated urine method detects BPC-157 at 0.1 ng/mL, and BPC-157 was stable in urine for at least four days in that study. How long it stays detectable after a human dose has not been published.

Do GHRPs and ipamorelin show up on tests?

Yes, by methods designed for them: urine methods detect GHRPs and their metabolites, some up to 47 hours after a single nasal dose in a volunteer.

Athletes, peptides and testing hub WADA status by compound The 2027 Prohibited List Therapeutic use exemptions Contaminated supplements and products WADA Prohibited List hub Do peptides show up on drug tests? Our report on the 2027 List TB-500 is not thymosin beta-4 The grey market

Sources

Studies are cited by PMID and checked on PubMed; figures are quoted from their abstracts. Read November 3, 2026.

  1. Thomas A, Höppner S, Geyer H, et al. Determination of growth hormone releasing peptides (GHRP) and their major metabolites in human urine for doping controls by means of liquid chromatography mass spectrometry. Anal Bioanal Chem 2011;401(2):507-516. PMID 21298258. Source
  2. Okano M, Sato M, Ikekita A, Kageyama S. Determination of growth hormone secretagogue pralmorelin (GHRP-2) and its metabolite in human urine by liquid chromatography/electrospray ionization tandem mass spectrometry. Rapid Commun Mass Spectrom 2010;24(14):2046-2056. PMID 20552695. Source
  3. Semenistaya E, Zvereva I, Thomas A, et al. Determination of growth hormone releasing peptides metabolites in human urine after nasal administration of GHRP-1, GHRP-2, GHRP-6, Hexarelin, and Ipamorelin. Drug Test Anal 2015;7(10):919-925. PMID 25869809. Source
  4. Memdouh S, Gavrilović I, Ng K, Cowan D, Abbate V. Advances in the detection of growth hormone releasing hormone synthetic analogs. Drug Test Anal 2021;13(11-12):1871-1887. PMID 34665524. Source
  5. Cox HD, Miller GD, Eichner D. Detection and in vitro metabolism of the confiscated peptides BPC 157 and MGF R23H. Drug Test Anal 2017;9(10):1490-1498. PMID 28035768. Source
  6. Tian T, Jing J, Li Y, Wang Y, Deng X, Shan Y. Stable isotope labeling-based nontargeted strategy for characterization of the in vitro metabolic profile of a novel doping BPC-157 in doping control by UHPLC-HRMS. Molecules 2023;28(21):7345. PMID 37959764. Source
  7. Ho ENM, Kwok WH, Lau MY, et al. Doping control analysis of TB-500, a synthetic version of an active region of thymosin β4, in equine urine and plasma by liquid chromatography-mass spectrometry. J Chromatogr A 2012;1265:57-69. PMID 23084823. Source
  8. Esposito S, Deventer K, Goeman J, Van der Eycken J, Van Eenoo P. Synthesis and characterization of the N-terminal acetylated 17-23 fragment of thymosin beta 4 identified in TB-500, a product suspected to possess doping potential. Drug Test Anal 2012;4(9):733-738. PMID 22962027. Source
  9. Rahaman KA, Muresan AR, Min H, et al. Simultaneous quantification of TB-500 and its metabolites in in-vitro experiments and rats by UHPLC-Q-Exactive orbitrap MS/MS and their screening by wound healing activities in-vitro. J Chromatogr B 2024;1235:124033. PMID 38382158. Source
  10. Hullstein IR, Malerod-Fjeld H, Dehnes Y, Hemmersbach P. Black market products confiscated in Norway 2011-2014 compared to analytical findings in urine samples. Drug Test Anal 2015;7(11-12):1025-1029. PMID 26607218. Source

This section reports the WADA Prohibited List, the anti-doping standards and published research, and our reading of them. It is not legal advice or an anti-doping ruling: an athlete's own anti-doping organisation gives the answer that counts. Grey Peptides sells nothing, links to no seller and rates none.