Skip to content

Reference information only. Therapept does not sell peptides and does not provide medical advice.Research-use notice

Therapept

Growth hormone secretagogue

Ipamorelin — evidence

What has been published, classified by the kind of document it is. This is not a protocol, not a score, and not a recommendation for use.

Evidence overview

5 records in this file

  • CLINICAL TRIAL1
  • ANIMAL1
  • REVIEW1
  • REGULATORY2

Research areas. Anti-doping; Clinical evidence appraisal; GH secretagogue pharmacology; Human GH-axis pharmacology; United States compounding.

Publication span. 1998–2026.

What we know

  • Preclinical pharmacology (Raun 1998) characterised it as a selective GH secretagogue in the systems tested.
  • A volunteer PK/PD study (Gobburu 1999) modelled GH release in humans. That is a hormone-axis experiment, not an approved indication.
  • It is the only compound in this library currently on FDA's active 503B Category 2 table (added 29 September 2023).

Editorial reading of the records below, labelled as Therapept analysis. How records are built

What remains uncertain

  • Controlled human data on clinical disease endpoints.
  • Whether commercial material containing unnatural amino acids is characterised to the standard FDA's Category 2 note flags as difficult.

Regulatory notes

FDA compounding Category 2

  • No approved drug product exists in Drugs@FDA.
  • Ipamorelin acetate is on FDA's active 503B Category 2 table, added 29 September 2023 — bulk drug substances that may present significant safety risks when used in compounding.
  • FDA's published concerns include immunogenicity risk from aggregation and impurities, and the difficulty of characterising an API containing unnatural amino acids.
  • A separate 503A nomination was withdrawn by the nominator.

Regulatory status describes how a substance is classified. It is not a safety assessment of any particular material.

Studies and documents

  1. REVIEW2026Narrative review

    Safety and efficacy of approved and unapproved peptide therapies for musculoskeletal injuries and athletic performance

    Mendias CL, Awan TMSports Medicine

    Objective
    To contrast approved peptide drugs with unapproved compounds marketed in sports medicine.
    Endpoint investigated
    Published safety/efficacy and regulatory status

    Sports Medicine review of approved and unapproved peptides marketed for injury and performance, including ipamorelin. Frames many unapproved peptides as having favourable animal findings and scarce rigorous human safety data.

    Limitations. Narrative. Not a substitute for primary PK papers.

    DOI 10.1007/s40279-026-02437-0Mendias and Awan, Sports Med (2026)Reviewed 12 September 2026

  2. REGULATORY2026Anti-doping listing

    WADA Prohibited List — S2.2.4 growth hormone secretagogues

    World Anti-Doping AgencyWADA Prohibited List

    Objective
    To record the 2026 Prohibited List entry.
    Endpoint investigated
    Sporting prohibition status

    Named at S2.2.4 among growth hormone secretagogues. Prohibited at all times; non-Specified.

    Limitations. Anti-doping classification only.

    WADA 2026 Prohibited ListReviewed 12 September 2026

  3. REGULATORY2023Regulatory listing

    FDA 503B Category 2 — ipamorelin acetate (added 29 September 2023)

    U.S. Food and Drug AdministrationFDA compounding communications

    Objective
    To record the active Category 2 placement and FDA's published concerns.
    Endpoint investigated
    Compounding classification

    Of the compounds in this library, ipamorelin acetate is the one currently on FDA's active 503B Category 2 table — bulk substances that may present significant safety risks when used in compounding. Published concerns include immunogenicity from aggregation and impurities, and characterisation of an API containing unnatural amino acids.

    Limitations. Category 2 is a compounding-risk classification, not a completed clinical evidence review.

    FDA — Certain bulk drug substances for use in compounding may present significant safety risksReviewed 12 September 2026

  4. CLINICAL TRIAL1999Human pharmacokinetic / pharmacodynamic study

    Pharmacokinetic-pharmacodynamic modeling of ipamorelin, a growth hormone releasing peptide, in human volunteers

    Gobburu JV, Agersø H, Jusko WJ, Ynddal LPharmaceutical Research

    Population
    Healthy human volunteers in a PK/PD study
    Objective
    To model the pharmacokinetics of ipamorelin and its relationship to GH release in volunteers.
    Endpoint investigated
    PK/PD of GH release, not a therapeutic endpoint

    Volunteer PK/PD study linking ipamorelin exposure to GH release. It shows a hormone-axis effect under experimental conditions. It does not test a clinical indication.

    Limitations. Healthy volunteers; hormone biomarker, not a disease endpoint; small experimental programme by later Phase 3 standards. No approved product followed.

    DOI 10.1023/A:1018955126402Gobburu et al., Pharm Res (1999)Reviewed 12 September 2026

  5. ANIMAL1998Preclinical pharmacology (in vitro and animal)

    Ipamorelin, the first selective growth hormone secretagogue

    Raun K, Hansen BS, Johansen NL, et al.European Journal of Endocrinology

    Population
    Pituitary in-vitro systems and animal GH-release models
    Objective
    To characterise ipamorelin as a growth-hormone secretagogue and compare selectivity with earlier GHRPs.
    Endpoint investigated
    GH release and selectivity versus cortisol, prolactin and ACTH in preclinical systems

    Foundational pharmacology paper describing ipamorelin as a pentapeptide GH secretagogue with greater selectivity than earlier GHRPs in the systems tested. It is a characterisation study, not a human efficacy trial.

    Limitations. Preclinical. Selectivity in these models is not a human safety or efficacy finding. No approved product exists.

    DOI 10.1530/eje.0.1390552Raun et al., Eur J Endocrinol (1998)Reviewed 12 September 2026

Last reviewed 3 September 2026 · Compiled by Therapept Editorial · How these records are built