Skip to content

Study · Measured the body's own peptide · 1990

2 results

Naloxone inhibits oxytocin release at orgasm in man.

Murphy MR, Checkley SA, Seckl JR, Lightman SL

The Journal of clinical endocrinology and metabolism1 Oct 1990Cited by 73 (Europe PMC)

PMID2401707 (opens in a new tab)DOI10.1210/jcem-71-4-1056 (opens in a new tab)PepBankPUB-02401707
Publisher pagePubMedAsk about this study
Jump to 2 results

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 study2

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 levelRandomized controlled trialMechanism

    In eight men, mean plasma oxytocin rose to 362% of baseline values at orgasm after placebo (saline).

    In plain wordsIn eight men, the body's own oxytocin level in blood rose at orgasm after placebo.

    Peptide
    Oxytocin
    Outcome
    IncreasePlasma oxytocin at orgasm with placebo
    Study

    n = 8

    Comparator
    Baseline
    Outcome group
    Sexual function · Reproductive and sexual health

    Measurements

    plasma oxytocin
    362 % of baseline
    orgasm with placebo

    Source sentences

    Summary
    Mean plasma oxytocin rose to 362% of baseline values at orgasm with placebo (saline)
    2 context sentences
    Summary · context
    We examined the effect of naloxone on plasma oxytocin levels during sexual activity in men.
    Summary · context
    Eight normal men took part in a double-blind, two-period, cross-over design.

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

  2. 02HumanEndogenous levelRandomized controlled trialMechanism

    In eight men, plasma oxytocin showed no increase at orgasm with naloxone, unlike the rise seen with placebo.

    In plain wordsIn eight men, the body's own oxytocin level in blood did not rise at orgasm after naloxone, unlike after placebo.

    Peptide
    Oxytocin
    Outcome
    DecreasePlasma oxytocin at orgasm with naloxone
    Study

    n = 8

    Comparator
    Placebo (saline)
    Outcome group
    Sexual function · Reproductive and sexual health

    Source sentences

    Summary
    Mean plasma oxytocin rose to 362% of baseline values at orgasm with placebo (saline) but showed no increase with naloxone (P less than 0.01).
    2 context sentences
    Summary · context
    We examined the effect of naloxone on plasma oxytocin levels during sexual activity in men.
    Summary · context
    Eight normal men took part in a double-blind, two-period, cross-over design.

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

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.

PepBank is a research reference. Talk to a doctor before you use any peptide.