Knowing the minimal detectable dose can facilitate the interpretation of a hair test result: II. Case example with ibutamoren (MK-677), a growth hormone secretagogue.

Kintz P, Gheddar L

Clinica chimica acta; international journal of clinical chemistry27 Aug 2025Cited by 1 (Europe PMC)

PMID40882886DOI10.1016/j.cca.2025.120578PepBankPUB-40882886

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Summary

The text of this summary is not shown here, because the article license does not allow reuse. Read it at the source (opens in a new tab)

Text rights: Publisher copyright. Results still quote short attributed sentences.

Results from this study4

2 results from studies that gave the peptide. 2 results from people.

01HumanCase report or seriesPharmacokinetics
In a male volunteer, ibutamoren was detected at 1.3 pg/mg in hair after a single 10 mg exposure.
In plain wordsIn a male volunteer, ibutamoren was detected in hair after a single dose.
Peptide
MK-677 (ibutamoren)
Outcome
Not applicableHair concentration after single exposure
Study
n = 1
Outcome group
Pharmacokinetics · Pharmacology
Studied dose
10 mg single dose · single exposureAs given in this study (human).
Measurements
Hair concentration
1.3 pg/mg
segment 0 to 1 cm
Source sentences
Summary
After a single exposure to 10 mg, ibutamoren tested positive at 1.3 pg/mg (segment 0 to 1 cm).
1 context sentence(design, population, supporting numbers)
Summary · context
A single 10 mg dose of ibutamoren, a growth hormone secretagogue, was administered to a male volunteer and his hair was collected 4 weeks after exposure.
Report a problemFND-4088288603
02HumanCase report or seriesPharmacokinetics
In an athletic-performance user, hair ibutamoren was 224 pg/mg after consumption of 60 capsules at 10 mg.
In plain wordsIn a user seeking better athletic performance, ibutamoren was detected in hair after repeated use.
Peptide
MK-677 (ibutamoren)
Outcome
Not applicableHair concentration after repeated use
Study
n = 1
Outcome group
Pharmacokinetics · Pharmacology
Studied dose
60 capsules of 10 mg over 90 days · 90 daysAs given in this study (human).
Measurements
Hair concentration
224 pg/mg
0 to 4 cm segment
Source sentences
Summary
After consumption of 60 capsules at 10 mg (whole vial), the 0 to 4 cm hair segment of a user for enhancement of athletic performances tested positive at 224 pg/mg, highlighting for the first time the incorporation in hair of this molecule.
1 context sentence(design, population, supporting numbers)
Summary · context
In addition, the hair specimen of a subject who took 60 capsules of 10 mg ibutamoren over 90 days was collected 4 weeks after drug discontinuation.
Report a problemFND-4088288604

Studies that did not test the peptide alone2

In this study, MK-677 (ibutamoren) was a lab tool or a carrier, part of a mix, or the subject of a lab method. These results are not evidence about taking MK-677 (ibutamoren).

03LabNot a test of MK-677 (ibutamoren) aloneIn vitro (cell-free)Other
In a hair assay for ibutamoren, linearity was verified from 0.5 to 250 pg/mg with R-squared of 0.9961.
In plain wordsIn lab tests, the ibutamoren hair assay was linear over the reported concentration range.
Peptide
MK-677 (ibutamoren)
Outcome
Not applicableAssay linearity
Study
n: not reported in source
Hair extraction and analytical assay
Outcome group
Analytical methods and detection · Pharmacology
Source sentences
Summary
Linearity was verified from 0.5 to 250 pg/mg (R² = 0.9961).
1 context sentence(design, population, supporting numbers)
Summary · context
After addition of bicalutamide-D₄ used as internal standard and incubation in phosphate buffer pH = 9.5, 25 mg of hair samples were extracted and purified by liquid/liquid extraction.
In this study, MK-677 (ibutamoren) was a lab tool or a carrier, part of a mix, or the subject of a lab method. This result is not evidence about taking MK-677 (ibutamoren).
Report a problemFND-4088288601
04LabNot a test of MK-677 (ibutamoren) aloneIn vitro (cell-free)Other
The ibutamoren hair assay had a detection limit of 0.1 pg/mg.
In plain wordsIn lab tests, the ibutamoren hair assay detected very low concentrations.
Peptide
MK-677 (ibutamoren)
Outcome
Not applicableDetection limit
Study
n: not reported in source
Hair extraction and analytical assay
Outcome group
Analytical methods and detection · Pharmacology
Source sentences
Summary
The limit of detection was 0.1 pg/mg.
1 context sentence(design, population, supporting numbers)
Summary · context
After addition of bicalutamide-D₄ used as internal standard and incubation in phosphate buffer pH = 9.5, 25 mg of hair samples were extracted and purified by liquid/liquid extraction.
In this study, MK-677 (ibutamoren) was a lab tool or a carrier, part of a mix, or the subject of a lab method. This result is not evidence about taking MK-677 (ibutamoren).
Report a problemFND-4088288602

AI wrote and checked these results. AI can make mistakes, so check important results against the source.

Version history

PepBank keeps every version of the data on this study. Status changes from Retraction Watch, Europe PMC and Crossref are listed with their source.

Version 2Current
14 Oct 2026, 05:02 UTC
Study results updated
Version 1
14 Oct 2026, 01:46 UTC
First added · source update from Europe PMC

Subjects

Terms as the source lists them.

Publication types

Journal Article

MeSH terms

Keywords

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