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Study · Measured the body's own peptide · 1989

3 results

Elevated plasma levels of oxytocin in women taking low-dose oral contraceptives. Identification of the plasma oxytocin with high performance liquid chromatography.

Stock S, Silber M, Uvnäs-Moberg K

Acta obstetricia et gynecologica Scandinavica1 Jan 1989Cited by 13 (Europe PMC)

PMID2678880 (opens in a new tab)DOI10.3109/00016348909087694 (opens in a new tab)PepBankPUB-02678880
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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 study3

No result from this study comes from a test of the peptide.

Natural levels measured2

These results measure the body's own peptide. Nobody was given the peptide. They are not evidence about taking it. They are left out of key results, evidence counts and charts.

  1. 01HumanEndogenous levelNon-randomized trialOther

    In women, low-dose oral contraceptives significantly increased plasma oxytocin concentrations in the luteal phase (p less than 0.02).

    In plain wordsIn women, low-dose birth control pills were linked to higher levels of the body's own oxytocin in blood.

    Peptide
    Oxytocin
    Outcome
    IncreasePlasma oxytocin with oral contraceptives
    Study

    n = 20

    Comparator
    No oral contraceptives
    Outcome group
    Sex hormones and fertility · Endocrine and hormones

    Source sentences

    Summary
    A significant increase in oxytocin concentrations was observed following ingestion of oral contraceptives (p less than 0.02).
    2 context sentences
    Summary · context
    Twenty women participated in an open cross-over study.
    Summary · context
    Six consecutive blood samples were drawn twice, with a 4-week interval, in the luteal phase of the menstrual cycle when the women were/were not taking oral contraceptives.

    This result measures the body's own Oxytocin. Nobody was given the peptide. It is not evidence about taking it.

  2. 02HumanEndogenous levelNon-randomized trialOther

    In women, those with the highest plasma oxytocin during a normal menstrual cycle had the largest increase when taking oral contraceptives.

    In plain wordsIn women, those with the highest natural oxytocin levels showed the biggest rise on birth control pills.

    Peptide
    Oxytocin
    Outcome
    Not applicableOxytocin rise by baseline level
    Study

    n = 20

    Comparator
    No oral contraceptives
    Outcome group
    Sex hormones and fertility · Endocrine and hormones

    Source sentences

    Summary
    Women with the highest oxytocin levels during a normal menstrual cycle increased their levels the most when on oral contraceptives.
    2 context sentences
    Summary · context
    Twenty women participated in an open cross-over study.
    Summary · context
    Six consecutive blood samples were drawn twice, with a 4-week interval, in the luteal phase of the menstrual cycle when the women were/were not taking oral contraceptives.

    This result measures the body's own Oxytocin. Nobody was given the peptide. It is not evidence about taking it.

Studies that did not test the peptide alone1

In this study, Oxytocin 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 Oxytocin.

  1. 03HumanNot a test of Oxytocin aloneNon-randomized trialOther

    In women's plasma, HPLC showed that immunoreactive oxytocin, with or without oral contraceptives, co-eluted with synthetic oxytocin standard.

    In plain wordsIn blood samples from women, the substance measured as oxytocin behaved like pure oxytocin in a laboratory separation test.

    Peptide
    Oxytocin
    Outcome
    Not applicableChromatographic identity of plasma immunoreactive oxytocin
    Study

    n = 20

    Outcome group
    Analytical methods and detection · Endocrine and hormones

    Source sentences

    Summary
    Analysis with high performance liquid chromatography demonstrated that immunoreactive oxytocin found in plasma, whether with or without oral contraceptives, co-eluted with synthetic oxytocin standard.
    2 context sentences
    Summary · context
    Twenty women participated in an open cross-over study.
    Summary · context
    Six consecutive blood samples were drawn twice, with a 4-week interval, in the luteal phase of the menstrual cycle when the women were/were not taking oral contraceptives.

    In this study, Oxytocin 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 Oxytocin.

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.

  1. Version 2Current

    11 Oct 2026, 20:03 UTC

    Study results updated

  2. Version 1

    9 Oct 2026, 02:52 UTC

    First added · source update from Europe PMC

Subjects

Terms as the source lists them.

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