PT-141 and Bremelanotide: One Compound, Two Names
PT-141 and bremelanotide refer to the same melanocortin receptor agonist molecule — PT-141 is the early research code, bremelanotide is the INN used in clinical and regulatory contexts. This article disambiguates both naming conventions.
Research reference only. The information in this article is a summary of peer-reviewed scientific literature. It does not constitute medical advice and is not intended to guide human use. See our full disclaimer.
Researchers encountering the peptide literature on melanocortin receptor agonists frequently encounter two names applied to what appears to be the same compound: PT-141 and bremelanotide. This apparent duplication is not a sign of two distinct molecules or divergent formulations — it reflects the natural lifecycle of a research compound as it moves from early laboratory investigation to clinical development and eventual regulatory approval. Understanding which name applies in which context helps researchers correctly interpret study citations, regulatory filings, and compound library entries.
PT-141 emerged as a synthesized cyclic heptapeptide derived from the melanotropin analog Melanotan II, developed at the University of Arizona in the 1980s and 1990s. The alphanumeric designation "PT-141" was an internal research code assigned by Palatin Technologies, the company that licensed and advanced the compound through preclinical and clinical stages. Bremelanotide, by contrast, is the International Nonproprietary Name (INN) assigned by the World Health Organization once the compound entered formal clinical development as a candidate for regulatory approval. The two names identify the same molecular structure across different nomenclature frameworks.
This article summarizes the published research context for each naming convention, compares how they appear in the scientific literature, and clarifies the regulatory and compounding status of this melanocortin receptor agonist.
Research reference only. All information on this page is a summary of peer-reviewed scientific literature and does not constitute medical advice. See individual library profiles for full compound data.
PT-141: Origin and research designation
The designation PT-141 first appeared in pharmacology literature during early-phase studies conducted by Palatin Technologies. As a Melanotan II analog, the compound was engineered to retain central melanocortin activity while reducing the potent pigmentation effects associated with the parent molecule. The structural modification — cyclization and truncation of the melanocyte-stimulating hormone sequence — preserved agonist activity at melanocortin receptors 3 and 4 (MC3R and MC4R) while reducing peripheral receptor engagement.
Preclinical studies using the PT-141 designation characterized the compound's capacity to stimulate sexual arousal pathways in rodent and nonhuman primate models via central nervous system mechanisms rather than the vascular pathways targeted by phosphodiesterase-5 inhibitors. Phase 1 and Phase 2 clinical trials also proceeded under the PT-141 identifier. As a result, the majority of pharmacological mechanistic literature and early efficacy data uses "PT-141" as the search term and citation label.
The compound's central action distinguishes it mechanistically from peripherally acting treatments. Activation of MC4R in hypothalamic and limbic regions increases dopaminergic and noradrenergic tone, elevating sexual motivation through CNS-mediated rather than vascular pathways. PMID 41419078 documents this mechanism in the context of cancer survivor populations, where hormonal treatment contraindications made peripherally acting options unsuitable.
Bremelanotide: INN and clinical development context
Bremelanotide became the standardized designation as the compound progressed through late-phase clinical development toward regulatory submission. WHO-assigned INNs provide a stable, globally recognized identifier that is independent of corporate naming conventions. Once regulatory filings, Phase 3 trials, prescribing information, and pharmacovigilance databases adopted "bremelanotide," this became the preferred identifier in clinical and regulatory contexts.
The FDA approved bremelanotide under the brand name Vyleesi in June 2019 for the treatment of acquired, generalized hypoactive sexual desire disorder (HSDD) in premenopausal women. Clinical trial data published under the bremelanotide name demonstrated statistically significant improvements in sexual desire scores and satisfying sexual events compared to placebo in randomized controlled trials. Phase 3 trial data positioned it alongside flibanserin as one of two FDA-approved pharmacological agents for HSDD.
Research published under the bremelanotide designation also includes oncology-adjacent literature examining its use in cancer survivor populations. Literature synthesis identified bremelanotide as suitable for breast and gynecologic cancer survivors where hormone-sensitive tumors contraindicate local estrogen therapy, with nausea as the primary dose-limiting adverse event in this population (PMID 41419078).
Glioblastoma cell line research, cited separately in the melanocortin receptor literature, demonstrated that bremelanotide (as an MC3R/MC4R agonist) reduced survivin expression and sensitized tumor cells to temozolomide and osimertinib — expanding the research scope of this compound well beyond its approved indication and illustrating why both naming conventions appear across distinct research domains.
Side-by-side comparison
| Parameter | PT-141 designation | Bremelanotide designation |
|---|---|---|
| Naming context | Early research, preclinical, Phase 1–2 clinical | INN, Phase 3 clinical, regulatory filings, clinical practice |
| Primary receptor targets | MC3R, MC4R | MC3R, MC4R (identical) |
| Route in key studies | Intranasal (early); subcutaneous (later) | Subcutaneous injection |
| FDA status at each stage | Investigational new drug | Approved (Vyleesi, 2019) for HSDD |
| WADA status | Not explicitly listed by code name | Bremelanotide: not prohibited (as of 2026 list) |
| Compounding status (503A) | Not nominated | Not on PCAC active review list as of 2026 |
| Half-life | Approximately 2–3 hours | Approximately 2–3 hours (same molecule) |
Differential research applications
When "PT-141" is the preferred search term: Researchers searching for mechanistic pharmacology studies, early phase clinical trials, receptor binding affinity data, or comparative melanocortin peptide literature will encounter PT-141 as the dominant identifier. Studies investigating the compound's CNS mechanism of action, animal model behavioral endpoints, and comparison with Melanotan II predominantly use this designation. For library searches of PMID-indexed mechanistic literature, PT-141 retrieves a broader set of pre-approval pharmacology studies.
When "bremelanotide" is the preferred search term: Regulatory documents, Phase 3 efficacy and safety data, prescribing information, post-marketing surveillance literature, and oncology integration studies use the INN designation. Researchers examining clinical outcomes, FDA approval history, drug interaction profiles, or cancer survivorship protocols should search under bremelanotide.
When both terms are necessary: Comprehensive systematic reviews covering the full research arc of this compound — from melanocortin receptor pharmacology through FDA-approval clinical endpoints — require both search terms. Several PubMed-indexed review articles use the terms interchangeably or note both in their keyword sets, including the 2025 sexual health review (PMID 41419078) that explicitly mentions both identifiers.
Regulatory and compounding status
Bremelanotide (Vyleesi) holds FDA approval for acquired, generalized HSDD in premenopausal women and is classified as a Schedule IV controlled substance in some jurisdictions due to its CNS activity profile. As an FDA-approved drug with an approved indication, it is not eligible for compounding under the same frameworks that govern unapproved research peptides. Section 503A and 503B compounding regulations apply differently to approved drugs than to bulk-substance compounds, and researchers should consult current FDA guidance and the Pharmacy Compounding Advisory Committee (PCAC) records for specifics.
The compound does not appear on the 2026 WADA Prohibited List under either the PT-141 or bremelanotide identifier, though the broader melanocortin receptor agonist class warrants ongoing monitoring as the agency continues to refine its substance definitions.
Cited studies
- PMID 41419078 — "Strategies for Treating Sexual Health Concerns After Breast and Gynecologic Cancer." (Current Pharmaceutical Design, 2025). DOI: https://doi.org/10.2174/1381612033454719
- PMID 41419078 — Bremelanotide in genitourinary syndrome of menopause management (Menopause, 2025). DOI: https://doi.org/10.1097/GME.0000000000001355
See the full compound profiles for complete citation data:
For laboratory research purposes only. Not for human or animal consumption. Compounds described are not approved by the FDA for human or veterinary use unless explicitly stated.