PT-141, also known by its nonproprietary name bremelanotide, is a synthetic cyclic heptapeptide analogue of alpha-melanocyte-stimulating hormone (α-MSH) that activates melanocortin receptors.[2][9] It...
Certificate of Analysis included with every order.
Technical Specifications
Purity
≥98%
Form
Lyophilized powder
Storage
-20°C
Molecular Weight
1025.16 Da (C50H68N14O10)
Sequence
Ac-Nle-cyclo(Asp-His-D-Phe-Arg-Trp-Lys)-OH
CAS Number
189691-06-3
About PT-141 (Bremelanotide)
PT-141, also known by its nonproprietary name bremelanotide, is a synthetic cyclic heptapeptide analogue of alpha-melanocyte-stimulating hormone (α-MSH) that activates melanocortin receptors.[2][9] Its structure is Ac-Nle-cyclo(Asp-His-D-Phe-Arg-Trp-Lys)-OH, with an acetylated N-terminus and a free carboxylic acid at the C-terminus; formula C50H68N14O10, molecular weight 1025.16.[2][13][14] Pepitiva supplies PT-141 as a lyophilized powder (10 mg vials, ≥98% purity, CAS 189691-06-3) for in vitro and preclinical research.
Regulatory status
Bremelanotide is an approved medicine: the FDA approved it on June 21, 2019, as a new molecular entity, for premenopausal women with acquired, generalized hypoactive sexual desire disorder (HSDD).[1][2] The label states that it is not indicated for postmenopausal women or men, nor to enhance sexual performance.[2] The product sold here is a research-grade peptide, not a pharmaceutical product, and is intended only for laboratory use.
Why researchers study PT-141
PT-141 was one of the first compounds shown to act on sexual desire through the central nervous system rather than on genital blood flow: in female rats it selectively increased solicitational behavior without changing lordosis, pacing or general motor activity.[9] It is a reference tool for the central melanocortin system.[10]
For research use only. Not for human consumption.
Quality & Storage
≥98% purity. Lyophilized powder. Storage: -20°C. For research purposes only.
Mechanism of Action
Melanocortin receptor agonism
Bremelanotide activates several melanocortin receptor subtypes non-selectively, with the potency order MC1R, MC4R, MC3R, MC5R, MC2R; binding at MC1R and MC4R is the most relevant at therapeutic exposure.[2] MC1R is expressed on melanocytes, where activation increases melanin and pigmentation.[2]
Central action
In rats, PT-141 increased c-Fos immunoreactivity in hypothalamic neurons, in a region that is connected to the penile corpus cavernosum.[8] A sponsor-affiliated review proposes that bremelanotide acts on presynaptic MC4R in the medial preoptic area of the hypothalamus, increasing dopamine release; this is based mainly on animal studies, and the label states that the mechanism in HSDD is unknown.[2][10]
Pharmacokinetics in humans
After a single subcutaneous administration, the mean terminal half-life was about 2.7 hours (range 1.9 to 4.0 hours); metabolism proceeds by hydrolysis of the peptide bonds of the cyclic peptide.[2]
Research Applications
Clinical research background
Phase 3 trials (2019): two 24-week placebo-controlled trials in 1,267 premenopausal women with HSDD found statistically significant improvements in desire and in distress related to low desire; nausea, flushing and headache were more common than with placebo. The trials were funded by the developers.[3]
52-week open-label extension (2019): no new safety signals; nausea (40.4%), flushing (20.6%) and headache (12.0%) were the most common related adverse events.[4]
Safety across development (2022): about 3,500 subjects in 43 studies; focal hyperpigmentation was rare with label-consistent use but occurred in more than one-third of subjects after up to 16 consecutive daily doses; small, transient blood pressure increases were observed.[5]
Ambulatory blood pressure (2017): systolic pressure rose by 2.4 to 3.0 mmHg relative to placebo in the 4 hours after dosing, with a reduction in heart rate.[6]
Independent reanalysis (2024): an independent analysis of the phase 3 data concluded that benefits were statistically modest and limited to outcomes with little validity evidence in HSDD.[7]
Laboratory research applications
Melanocortin receptor pharmacology: subtype selectivity profiling across MC1R to MC5R.[2]
Behavioral neuroscience: appetitive versus reflexive components of sexual behavior in rodent models.[9]
Hypothalamic circuits: MC4R signaling and dopamine release in the medial preoptic area.[10]
Analytical methods: LC-HRMS identification of bremelanotide and the related peptide melanotan II in seized products.[11]
Related neuroendocrine research:Kisspeptin has also been studied in HSDD through a different pathway, the KISS1R/GnRH axis.
The clinical findings above are summarized as scientific background only. This product is sold for laboratory research and is not intended for human or veterinary use.
Storage & Handling Guidelines
Proper storage and handling are essential to maintain peptide integrity and ensure reliable research results. All Pepitiva Biolabs peptides are supplied as lyophilized (freeze-dried) powder, which provides excellent long-term stability when stored correctly. Store lyophilized peptides at -20°C for long-term storage or 2-8°C for short-term use. Once reconstituted, peptide solutions should be stored at 2-8°C and used within the timeframe specified in the product documentation. Always use sterile bacteriostatic water for reconstitution and handle peptides in a clean laboratory environment to prevent contamination. Avoid repeated freeze-thaw cycles, as thermal stress can cause peptide degradation and loss of biological activity.
Quality Control & Certification
This product is manufactured under strict quality control protocols and has been verified through comprehensive analytical testing. Each batch undergoes reverse-phase HPLC analysis for purity determination and electrospray ionization mass spectrometry (ESI-MS) for molecular identity confirmation. A detailed Certificate of Analysis (COA) is available for download, documenting purity percentage, molecular weight verification, appearance, and recommended storage conditions. Pepitiva Biolabs maintains batch-level traceability from synthesis through delivery, ensuring complete transparency and quality assurance for your research.
Frequently Asked Questions
What is the molecular weight of PT-141?
1025.16 (KEGG DRUG D06569; PubChem lists 1025.2 g/mol). Formula C50H68N14O10, CAS 189691-06-3.
Is PT-141 the same as bremelanotide?
Yes. PT-141 is the development code and bremelanotide is the nonproprietary name of the same cyclic peptide, Ac-Nle-cyclo(Asp-His-D-Phe-Arg-Trp-Lys)-OH.
Is bremelanotide FDA approved?
Yes. The FDA approved it on June 21, 2019 (application 210557) for premenopausal women with acquired, generalized hypoactive sexual desire disorder. The research-grade peptide sold here is not a pharmaceutical product and is for laboratory use only.
Which receptors does PT-141 act on?
Melanocortin receptors, non-selectively, with the potency order MC1R, MC4R, MC3R, MC5R, MC2R. MC4R activity is linked to its central effects and MC1R activity to pigmentation.
What is PT-141 used for in research?
Melanocortin receptor pharmacology, studies of central control of sexual behavior in animal models, and analytical method development. It is sold here for laboratory research only.
How should PT-141 be stored?
Keep the lyophilized powder at −20 °C, protected from light and moisture.
Is this product approved for human use?
No. This product is intended exclusively for in vitro scientific research and laboratory use. It is not approved for human or veterinary use, not intended for diagnostic or therapeutic purposes, and should not be administered to humans or animals under any circumstances.
How do I reconstitute this peptide?
Add sterile bacteriostatic water slowly to the vial, directing the stream against the glass wall rather than directly onto the lyophilized powder. Gently swirl the vial until the powder is fully dissolved — do not shake vigorously. The recommended reconstitution volume depends on your desired concentration. Refer to the product documentation for specific guidance.
Can I get a Certificate of Analysis (COA)?
Yes. A Certificate of Analysis is included with every order and is also available for download from the product page. The COA documents HPLC purity, mass spectrometry identity confirmation, batch number, production date, and storage recommendations.
Scientific References
U.S. Food and Drug Administration. Drugs@FDA: application 210557 (bremelanotide acetate); original approval June 21, 2019, new molecular entity. Source
U.S. Food and Drug Administration. Bremelanotide injection, prescribing information (NDA 210557), 2019: sections 1, 5, 11 and 12. Source
Kingsberg SA, Clayton AH, Portman D, et al. Bremelanotide for the Treatment of Hypoactive Sexual Desire Disorder: Two Randomized Phase 3 Trials. Obstet Gynecol. 2019;134(5):899-908. PubMed
Simon JA, Kingsberg SA, Portman D, et al. Long-Term Safety and Efficacy of Bremelanotide for Hypoactive Sexual Desire Disorder. Obstet Gynecol. 2019;134(5):909-917. PubMed
Clayton AH, Kingsberg SA, Portman D, et al. Safety Profile of Bremelanotide Across the Clinical Development Program. J Womens Health (Larchmt). 2022;31(2):171-182. PubMed
White WB, Myers MG, Jordan R, Lucas J. Usefulness of ambulatory blood pressure monitoring to assess the melanocortin receptor agonist bremelanotide. J Hypertens. 2017;35(4):761-768. PubMed
Spielmans GI, Ellefson EM. Small Effects, Questionable Outcomes: Bremelanotide for Hypoactive Sexual Desire Disorder. J Sex Res. 2024;61(4):540-561. PubMed
Molinoff PB, Shadiack AM, Earle D, et al. PT-141: a melanocortin agonist for the treatment of sexual dysfunction. Ann N Y Acad Sci. 2003;994:96-102. PubMed
Pfaus JG, Shadiack A, Van Soest T, et al. Selective facilitation of sexual solicitation in the female rat by a melanocortin receptor agonist. Proc Natl Acad Sci U S A. 2004;101(27):10201-10204. PubMed
Pfaus JG, Sadiq A, Spana C, Clayton AH. The neurobiology of bremelanotide for the treatment of hypoactive sexual desire disorder in premenopausal women. CNS Spectr. 2022;27(3):281-289. PubMed
Mestria S, Odoardi S, Frison G, Strano Rossi S. LC-HRMS characterization of the skin pigmentation and sexual enhancers melanotan II and bremelanotide sold on the black market of performance and image enhancing drugs. Drug Test Anal. 2021;13(4):876-882. PubMed
Dhillon S, Keam SJ. Bremelanotide: First Approval. Drugs. 2019;79(14):1599-1606. PubMed
PubChem. Bremelanotide, CID 9941379: C50H68N14O10, 1025.2 g/mol, CAS 189691-06-3. Source
KEGG DRUG D06569: Bremelanotide (PT-141). Formula C50H68N14O10, molecular weight 1025.16. Source
Sources are peer-reviewed publications indexed in PubMed and trial registrations on ClinicalTrials.gov. Each citation was checked against its PubMed record.
For research use only. Not for human consumption.
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