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Study · Animal study (in vivo) · horse · 2026

5 results

Low-dose histrelin for ovulation induction in mares: a partially randomized crossover pilot study.

de Barros Fogagnoli L, Jose KCA, Weckl R, Mota CMO, Fernandes MO, Machado RC, Camargo CE, Michelotto PV

Veterinary research communications20 Oct 2026

PMID42897392 (opens in a new tab)PMCIDPMC13680520 (opens in a new tab)DOI10.1007/s11259-026-11583-9 (opens in a new tab)PepBankPUB-42897392
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Summary

This partially randomized crossover pilot study evaluated reduced doses of histrelin for ovulation induction in mares and compared intramuscular (IM) administration with pharmacopuncture at the Bai-hui and Yan-chi acupoints. Eleven mares were enrolled, of which nine completed all eight protocols and were included in the analyses. The protocols comprised 250 µg histrelin IM (standard dose), 75 µg IM, 25 µg IM, no intervention, saline at Bai-hui, saline at Yan-chi, 25 µg histrelin at Bai-hui, and 25 µg histrelin at Yan-chi. Ovulation was assessed by transrectal ultrasonography at scheduled examinations until detected, with ovulation within 48 h as the primary outcome. Ovulations first detected at 24 h were excluded from the primary analysis. Ovulation within 48 h occurred in 88.9% (8/9) of observations with 250 µg IM, 87.5% (7/8) with 75 µg IM, 87.5% (7/8) with 25 µg IM, 37.5% (3/8) with no intervention, 50.0% (3/6) with saline at Bai-hui, 100% (9/9) with 25 µg histrelin at Bai-hui, 12.5% (1/8) with saline at Yan-chi, and 87.5% (7/8) with 25 µg histrelin at Yan-chi. Exact 95% confidence intervals were wide, reflecting the small sample size. Exploratory pairwise comparisons with the no-intervention protocol were performed without adjustment for multiple comparisons and should be interpreted cautiously. The findings provide preliminary evidence that reduced histrelin doses, including 25 µg, may induce ovulation within 48 h in mares. However, this study did not demonstrate an advantage of pharmacopuncture over IM administration of the same reduced dose. Larger, fully randomized studies are required to confirm the efficacy of reduced-dose histrelin and determine whether administration at specific acupoints provides any additional effect.
CC BYText from Europe PMC. Highlighted sentences are the source of results.

Results from this study5

5 results from studies that gave the peptide. No result from this study comes from people.

  1. 01AnimalAnimal study (in vivo)Efficacy outcome

    In mares, ovulation within 48 h occurred in 88.9% (8/9) after 250 µg intramuscular histrelin.

    In plain wordsIn mares, 88.9% ovulated within 48 h after 250 µg intramuscular histrelin.

    Peptide
    Histrelin
    Outcome
    Direction not reportedOvulation within 48 h
    Study

    horsen = 9

    Mares
    Analysis
    Primary
    Outcome group
    Sex hormones and fertility · Reproductive and sexual health
    Studied dose
    250 µg · intramuscularAs given in this study (horse).

    Source sentences

    Summary
    Ovulation within 48 h occurred in 88.9% (8/9) of observations with 250 µg IM
    3 context sentences
    Summary · context
    This partially randomized crossover pilot study evaluated reduced doses of histrelin for ovulation induction in mares and compared intramuscular (IM) administration with pharmacopuncture at the Bai-hui and Yan-chi acupoints.
    Summary · context
    Ovulation was assessed by transrectal ultrasonography at scheduled examinations until detected, with ovulation within 48 h as the primary outcome.
    Summary · context
    Ovulations first detected at 24 h were excluded from the primary analysis.
  2. 02AnimalAnimal study (in vivo)Efficacy outcome

    In mares, ovulation within 48 h occurred in 100% (9/9) after 25 µg histrelin at Bai-hui.

    In plain wordsIn mares, 100% ovulated within 48 h after 25 µg histrelin at Bai-hui.

    Peptide
    Histrelin
    Outcome
    Direction not reportedOvulation within 48 h
    Study

    horsen = 9

    Mares
    Analysis
    Primary
    Outcome group
    Sex hormones and fertility · Reproductive and sexual health
    Studied dose
    25 µg · pharmacopuncture at Bai-huiAs given in this study (horse).

    Source sentences

    Summary
    100% (9/9) with 25 µg histrelin at Bai-hui
    3 context sentences
    Summary · context
    This partially randomized crossover pilot study evaluated reduced doses of histrelin for ovulation induction in mares and compared intramuscular (IM) administration with pharmacopuncture at the Bai-hui and Yan-chi acupoints.
    Summary · context
    Ovulation was assessed by transrectal ultrasonography at scheduled examinations until detected, with ovulation within 48 h as the primary outcome.
    Summary · context
    Ovulations first detected at 24 h were excluded from the primary analysis.
  3. 03AnimalAnimal study (in vivo)Efficacy outcome

    In mares, ovulation within 48 h occurred in 87.5% (7/8) after 75 µg intramuscular histrelin.

    In plain wordsIn mares, 87.5% ovulated within 48 h after 75 µg intramuscular histrelin.

    Peptide
    Histrelin
    Outcome
    Direction not reportedOvulation within 48 h
    Study

    horsen = 8

    Mares
    Analysis
    Primary
    Outcome group
    Sex hormones and fertility · Reproductive and sexual health
    Studied dose
    75 µg · intramuscularAs given in this study (horse).

    Source sentences

    Summary
    87.5% (7/8) with 75 µg IM
    3 context sentences
    Summary · context
    This partially randomized crossover pilot study evaluated reduced doses of histrelin for ovulation induction in mares and compared intramuscular (IM) administration with pharmacopuncture at the Bai-hui and Yan-chi acupoints.
    Summary · context
    Ovulation was assessed by transrectal ultrasonography at scheduled examinations until detected, with ovulation within 48 h as the primary outcome.
    Summary · context
    Ovulations first detected at 24 h were excluded from the primary analysis.
  4. 04AnimalAnimal study (in vivo)Efficacy outcome

    In mares, ovulation within 48 h occurred in 87.5% (7/8) after 25 µg intramuscular histrelin.

    In plain wordsIn mares, 87.5% ovulated within 48 h after 25 µg intramuscular histrelin.

    Peptide
    Histrelin
    Outcome
    Direction not reportedOvulation within 48 h
    Study

    horsen = 8

    Mares
    Analysis
    Primary
    Outcome group
    Sex hormones and fertility · Reproductive and sexual health
    Studied dose
    25 µg · intramuscularAs given in this study (horse).

    Source sentences

    Summary
    87.5% (7/8) with 25 µg IM
    3 context sentences
    Summary · context
    This partially randomized crossover pilot study evaluated reduced doses of histrelin for ovulation induction in mares and compared intramuscular (IM) administration with pharmacopuncture at the Bai-hui and Yan-chi acupoints.
    Summary · context
    Ovulation was assessed by transrectal ultrasonography at scheduled examinations until detected, with ovulation within 48 h as the primary outcome.
    Summary · context
    Ovulations first detected at 24 h were excluded from the primary analysis.
  5. 05AnimalAnimal study (in vivo)Efficacy outcome

    In mares, ovulation within 48 h occurred in 87.5% (7/8) after 25 µg histrelin at Yan-chi.

    In plain wordsIn mares, 87.5% ovulated within 48 h after 25 µg histrelin at Yan-chi.

    Peptide
    Histrelin
    Outcome
    Direction not reportedOvulation within 48 h
    Study

    horsen = 8

    Mares
    Analysis
    Primary
    Outcome group
    Sex hormones and fertility · Reproductive and sexual health
    Studied dose
    25 µg · pharmacopuncture at Yan-chiAs given in this study (horse).

    Source sentences

    Summary
    87.5% (7/8) with 25 µg histrelin at Yan-chi.
    3 context sentences
    Summary · context
    This partially randomized crossover pilot study evaluated reduced doses of histrelin for ovulation induction in mares and compared intramuscular (IM) administration with pharmacopuncture at the Bai-hui and Yan-chi acupoints.
    Summary · context
    Ovulation was assessed by transrectal ultrasonography at scheduled examinations until detected, with ovulation within 48 h as the primary outcome.
    Summary · context
    Ovulations first detected at 24 h were excluded from the primary analysis.

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, 16:35 UTC

    First added · source update from Europe PMC

Subjects

Terms as the source lists them.

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