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Study · Non-randomized trial · n = 7 · 1986

4 results

Gonadotropin releasing hormone (GnRH) agonists in male contraception.

Swerdloff RS, Steiner BS, Bhasin S

Medical biology1 Jan 1986Cited by 3 (Europe PMC)

PMID2939304 (opens in a new tab)PepBankPUB-02939304
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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

4 results from studies that gave the peptide. 4 results from people.

  1. 01HumanNon-randomized trialEfficacy outcome

    In men receiving nafarelin infusion and background testosterone, 3 of 7 were azoospermic.

    In plain wordsIn men receiving nafarelin infusion and background testosterone, 3 of 7 had no sperm in semen.

    Peptide
    Nafarelin
    Outcome
    Not applicableAzoospermia with infusion
    Study

    n = 7

    Outcome group
    Sex hormones and fertility · Reproductive and sexual health
    Studied dose
    400 micrograms daily · constant subcutaneous infusion · 16 weeksAs given in this study (human).

    Measurements

    Azoospermic subjects
    3 subjects
    infusion 400 micrograms/day, of 7 subjects

    Source sentences

    Summary
    With infusion treatment, 3 of 7 subjects were azoospermic, a fourth subject had less than 1 million sperm per ml of semen and 5 of 7 subjects had sperm counts less than 5 million per ml.
    3 context sentences
    Summary · context
    In this report 400 micrograms of the GnRH agonist was given daily by constant subcutaneous infusion and the results compared to an earlier study in which 200 micrograms of the same agonist was given as a single daily subcutaneous injection.
    Summary · context
    A potent gonadotropin releasing hormone (GnRH) agonist, D(Nal2)6 GnRH (Nafarelin) has been administered to two groups of normal men for 16 weeks by two routes in order to assess its effectiveness in suppressing spermatogenesis.
    Summary · context
    All subjects in both groups received an intramuscular injection of testosterone enanthate (200 mg) every two weeks to prevent symptoms of androgen deficiency.
  2. 02HumanNon-randomized trialEfficacy outcome

    In men receiving nafarelin infusion and background testosterone, a fourth subject had less than 1 million sperm/ml.

    In plain wordsIn men receiving nafarelin infusion and background testosterone, another subject had fewer than 1 million sperm/ml.

    Peptide
    Nafarelin
    Outcome
    Not applicableSperm count below one million
    Study

    n = 7

    Outcome group
    Sex hormones and fertility · Reproductive and sexual health
    Studied dose
    400 micrograms daily · constant subcutaneous infusion · 16 weeksAs given in this study (human).

    Measurements

    Sperm concentration
    < 1 million/ml
    one further subject (a fourth) on infusion

    Source sentences

    Summary
    With infusion treatment, 3 of 7 subjects were azoospermic, a fourth subject had less than 1 million sperm per ml of semen and 5 of 7 subjects had sperm counts less than 5 million per ml.
    3 context sentences
    Summary · context
    In this report 400 micrograms of the GnRH agonist was given daily by constant subcutaneous infusion and the results compared to an earlier study in which 200 micrograms of the same agonist was given as a single daily subcutaneous injection.
    Summary · context
    A potent gonadotropin releasing hormone (GnRH) agonist, D(Nal2)6 GnRH (Nafarelin) has been administered to two groups of normal men for 16 weeks by two routes in order to assess its effectiveness in suppressing spermatogenesis.
    Summary · context
    All subjects in both groups received an intramuscular injection of testosterone enanthate (200 mg) every two weeks to prevent symptoms of androgen deficiency.
  3. 03HumanNon-randomized trialEfficacy outcome

    In men receiving nafarelin infusion and background testosterone, 5 of 7 had fewer than 5 million sperm/ml.

    In plain wordsIn men receiving nafarelin infusion and background testosterone, 5 of 7 had fewer than 5 million sperm/ml.

    Peptide
    Nafarelin
    Outcome
    Not applicableSperm count below five million
    Study

    n = 7

    Outcome group
    Sex hormones and fertility · Reproductive and sexual health
    Studied dose
    400 micrograms daily · constant subcutaneous infusion · 16 weeksAs given in this study (human).

    Measurements

    Subjects with sperm count below 5 million/ml
    5 subjects
    infusion 400 micrograms/day, of 7 subjects

    Source sentences

    Summary
    With infusion treatment, 3 of 7 subjects were azoospermic, a fourth subject had less than 1 million sperm per ml of semen and 5 of 7 subjects had sperm counts less than 5 million per ml.
    3 context sentences
    Summary · context
    In this report 400 micrograms of the GnRH agonist was given daily by constant subcutaneous infusion and the results compared to an earlier study in which 200 micrograms of the same agonist was given as a single daily subcutaneous injection.
    Summary · context
    A potent gonadotropin releasing hormone (GnRH) agonist, D(Nal2)6 GnRH (Nafarelin) has been administered to two groups of normal men for 16 weeks by two routes in order to assess its effectiveness in suppressing spermatogenesis.
    Summary · context
    All subjects in both groups received an intramuscular injection of testosterone enanthate (200 mg) every two weeks to prevent symptoms of androgen deficiency.
  4. 04HumanNon-randomized trialEfficacy outcome

    In normal men also receiving testosterone, nafarelin 400 micrograms/day by constant subcutaneous infusion suppressed spermatogenesis more than 200 micrograms/day by single daily injection in an earlier study; whether route or dose explains the difference is unclear.

    In plain wordsIn men given testosterone too, higher-dose nafarelin infusion cut sperm production more than lower-dose injection in an earlier study; dose versus route is unclear.

    Peptide
    Nafarelin
    Outcome
    DecreaseSpermatogenesis versus earlier injection regimen
    Study

    n: not reported in source

    Comparator
    Nafarelin 200 micrograms daily subcutaneous injection, with shared testosterone
    Outcome group
    Sex hormones and fertility · Reproductive and sexual health
    Studied dose
    400 micrograms daily · constant subcutaneous infusion · 16 weeksAs given in this study (human).

    Source sentences

    Summary
    The higher dose infusion regimen was much more effective in suppressing spermatogenesis than the single daily injection.
    3 context sentences
    Summary · context
    In this report 400 micrograms of the GnRH agonist was given daily by constant subcutaneous infusion and the results compared to an earlier study in which 200 micrograms of the same agonist was given as a single daily subcutaneous injection.
    Summary · context
    A potent gonadotropin releasing hormone (GnRH) agonist, D(Nal2)6 GnRH (Nafarelin) has been administered to two groups of normal men for 16 weeks by two routes in order to assess its effectiveness in suppressing spermatogenesis.
    Summary · context
    All subjects in both groups received an intramuscular injection of testosterone enanthate (200 mg) every two weeks to prevent symptoms of androgen deficiency.

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

    28 Oct 2026, 02:03 UTC

    Study results updated

  2. Version 1

    27 Oct 2026, 16:36 UTC

    First added · source update from Europe PMC

Subjects

Terms as the source lists them.

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