PT-141 Research Guidebremelanotide · C-terminal acid · not Melanotan II · not Vyleesi

SRP product and index pages do not print CAS, UNII, PubChem CID, molecular formula, sequence, termini, salt stoichiometry, or a public COA. Identity below is taken only from opened public registries and from primary papers that name PT-141 / bremelanotide.

Opened SRP product page (16 August 2026): title “PT-141 10 mg Melanocortin Research Peptide Vial”. Subhead: “PT-141 (10 mg / 3 mL Vial).” Also Known As: Bremelanotide, PT-141 Acetate. Bullets: 10 mg lyophilized research compound in a 3 mL research vial; COA available for batch verification; Made in the USA; high-purity research material; intended for qualified laboratory and analytical research; securely packaged; For Research Use Only. Not for human or veterinary use. Description: supplied for controlled laboratory evaluation of PT-141 within Research Compounds studies. Research material: PT-141. Listed strength: 10 mg Vial. Research category: Research Compounds. Footer: for laboratory research only; not for human or animal use, consumption, administration, diagnosis, treatment, or therapeutic application. Price printed $60.00. Availability: “5 in stock (can be backordered).” Shipping-box fields: Weight 1 lbs; Dimensions 1 × .5 × 2 in. Reviews (0). Price, stock, and shipping-box fields are vendor listings, not chemistry.

Not printed on the opened product page and therefore not claimed as SRP-verified: cyclic sequence; free-base vs acetate salt stoichiometry; CAS; UNII; CID; a public COA file; a published 10 mg laboratory dose.

Opened SRP index card (compound-research-guides, 16 August 2026): “PT-141 (10 mg Vial)” under Other; tag Evidence profile (not “Dedicated evidence guide”); evidence tier Human clinical evidence; regulated analogue context. Overview: “PT-141 is bremelanotide, a cyclic melanocortin-receptor agonist developed from melanocortin peptide research.” Mechanism: acts centrally through melanocortin receptors involved in sexual response; mechanism differs from vasodilator drugs. Evidence: a regulated prescription bremelanotide product has clinical-trial and labeling evidence for a specific indication; that evidence does not establish equivalence of an unapproved research vial. Quality note: check the current FDA label for the regulated product and distinguish it from research material in formulation, manufacturing, and oversight. Last editorial review printed on that index: August 2026.

Opened dedicated-guide URL http://simpleresearchpeptides.com/research-compound-directory/pt-141-research-guide/ returned HTTP 404 on 16 August 2026. This page is written for that missing standalone listing.

Critical identity point. CID 9941379 / UNII 6Y24O4F92S is the C-terminal carboxylic acid cyclic lactam. Melanotan II (CID 92432; InChIKey JDKLPDJLXHXHNV-MFVUMRCOSA-N) is the C-terminal carboxamide of the same ring. King 2007 (PMID 17584130; PMC 2694735 opened abstract): “PT-141, which is the carboxylate derivative of MT-II.” Formula C50H68N14O10 vs C50H69N15O9. InChIKeys share the stereo suffix MFVUMRCOSA-N but have different first blocks. An SRP “PT-141 10 mg” lot is not automatically the acetate salt, not Melanotan II, not Vyleesi, and not afamelanotide. Confirm sequence, C-terminus (acid vs amide), stereochemistry (D-Phe), lactam closure, and salt on a COA / LC-MS.

Registry chaos that must not be collapsed.

• SRP prints “Also Known As: Bremelanotide, PT-141 Acetate.” That vendor string is not a COA. PubChem depositor synonym “PT-141 FREE BASE” sits on CID 9941379. NCATS acetate UNII PV2WI7495P / CAS 1607799-13-2 is the approved-product salt record. Neither string proves the SRP lot counter-ion or acetate stoichiometry (DailyMed: 1 ≤ x ≤ 2 acetic acid on the approved product).
• openFDA unii on the Vyleesi NDA record prints PV2WI7495P (acetate). DailyMed active moiety is 6Y24O4F92S (free base). Both are real. Do not assign the acetate UNII to the free-base CID, or the free-base UNII to the salt.
• IUPHAR ligand 10408 is bremelanotide (approved: true). Ligand 1323 is MT-II (approved: false; INN empty). Ligand 1324 is afamelanotide (EMA 2014 / FDA 2019). Ligand 1320 is alpha-MSH (approved: false). Those are four different records.
• Vyleesi approval does not convert a research-market lyophilized vial into NDA 210557.

Catalog “melanocortin research” language does not convert a research cyclic heptapeptide into Vyleesi, Scenesse, Melanotan II, endogenous alpha-MSH, or the KPV tripeptide.

The standalone vial is not Melanotan II. One atom-level difference: MT-II is the 23-carboxamide; bremelanotide is the 23-carboxylic acid (IUPHAR IUPAC; PubChem condensed -OH vs -NH2). King 2007 (PMID 17584130) and Hadley and Dorr 2006 (PMID 16412534) describe PT-141 as the Palatin carboxylate analogue that entered human sexual-dysfunction development after MT-II. IUPHAR ligand 1323 is approved: false. The opened SRP Melanotan II 10 mg page is a different SKU.

The standalone vial is not Vyleesi. Vyleesi is NDA 210557, a sterile glycerin/water autoinjector solution (DailyMed). The SRP listing is a 10 mg lyophilized research vial with an RUO footer. Formulation, manufacturing, fill, and oversight are not the same. Opened SRP index: regulated-product evidence “does not establish equivalence of an unapproved research vial.”

The standalone vial is not Melanotan I / afamelanotide / Scenesse. Sawyer 1980 (PMID 6777774) made linear [Nle4, D-Phe7]-alpha-MSH. That linear 13-mer is IUPHAR ligand 1324 (afamelanotide; Scenesse; EMA 2014 / FDA 2019). Different sequence length, formula, and InChIKey.

The standalone vial is not alpha-MSH. The parent hormone is the 13-residue linear peptide (IUPHAR 1320). PT-141 is a truncated, Nle4 / D-Phe7, Asp–Lys lactam, C-terminal acid analogue.

The standalone vial is not KPV. KPV is three residues (Lys-Pro-Val) at the C-terminus of alpha-MSH. PT-141 is a cyclic 4–10 fragment analogue. The opened SRP KPV index card is a Recovery / Inflammation Preclinical evidence entry. Do not cite KPV colitis or keratinocyte papers as PT-141 evidence.

Do not equate this vial with alpha-MSH, ACTH, Melanotan I, afamelanotide / Scenesse, Melanotan II, KPV, or the Vyleesi autoinjector. Research use only.

Opened primary papers and the opened DailyMed label support a non-selective cyclic melanocortin-agonist working model. It is not a treatment claim for this vial. It was not generated with an SRP 10 mg vial. Observed means a measurement in an opened paper or opened label. Proposed means a hypothesis. Not shown means the opened sources did not establish it for a research-market lot.

SRP index Evidence profile for this SKU: Human clinical evidence; regulated analogue context. That is the house tier. This page does not upgrade a research vial to NDA 210557. PT-141 ≠ Melanotan II ≠ afamelanotide ≠ alpha-MSH ≠ KPV ≠ Vyleesi. Historical language is not a completed therapeutic program for this vial.

ClinicalTrials.gov (opened; this molecule as intervention). query.intr=bremelanotide returned totalCount 10 (API v2; versionHolder 2026-08-14). All ten IDs were returned on that list. Those ten records belong to bremelanotide / Vyleesi development or post-approval work. They do not authorize a human-use protocol, a dose, a reconstitution recipe, or a claim that this SRP vial is a sexual-function product.

Read the “not this vial” column in your head. A regulated autoinjector product exists. That approval does not convert a research-market lyophilized vial into NDA 210557. Historical routes, trial arms, and label strengths are study / product conditions, not instructions.

• IUPHAR ligand 10408: type Peptide; approved: true; approvalSource FDA (2019); INN bremelanotide; INN number 8737.
• openFDA Drugs@FDA: NDA 210557; brand VYLEESI; generic BREMELANOTIDE; sponsor COSETTE; ORIG submission_status_date 20190621; Type 1 NME; route SUBCUTANEOUS; substance_name BREMELANOTIDE ACETATE.
• DailyMed (opened 16 August 2026): VYLEESI-bremelanotide injection; NDC 0713-0897-04 / 0713-0897-06; packager Cosette Pharmaceuticals, Inc.; Category HUMAN PRESCRIPTION DRUG LABEL; Marketing Status New Drug Application; Initial U.S. Approval 2019; revised 3/2024. Indication text is for premenopausal women with acquired, generalized HSDD with listed exclusions and Limitations of Use (not for postmenopausal women or men; not to enhance sexual performance). Contraindication: uncontrolled hypertension or known cardiovascular disease. That is label text for Vyleesi. It is not a treatment claim for this SKU.
• DailyMed description of the approved product: sterile clear solution in a pre-filled syringe / single-dose autoinjector; inactive ingredients 2.5% glycerin, sterile water, HCl or NaOH for pH. That is not a 10 mg lyophilized research vial.
• NCATS UNII 6Y24O4F92S: US Approved Rx (2019); source NDA210557. Acetate UNII PV2WI7495P: separate salt record; CAS 1607799-13-2.
• SRP product page: Research Use Only footer. No public COA on the opened product HTML.
• This SKU is a research-use-only lyophilized vial. It is not Vyleesi and not Scenesse.

• No human reconstitution, administration, or dosing protocol.
• No claim that this vial is Vyleesi, a sexual-function product, a tanning product, or a performance product.
• No claim that PT-141 is Melanotan II, afamelanotide / Scenesse, alpha-MSH, or KPV.
• No invented CAS, UNII, CID, NCT, or PMID.
• No use of acetate UNII PV2WI7495P as proof of the SRP lot salt.
• No transcription of DailyMed section 2 as a protocol for this SKU.
• Phase 3 / label outcomes apply to the approved autoinjector product in a defined population. They do not establish efficacy or safety of a research-market 10 mg vial.
• Spielmans 2024 (PMID 36809187) is listed so the Phase 3 program is not presented as unquestioned. It is not a reason to invent a contrary NCT.

Each card is a single opened record. Historical routes, trial arms, and label strengths are study / product conditions, not instructions. No reconstitution scheme appears here.

PT-141 / bremelanotide is an investigational laboratory research peptide on this listing. A different formulated product (Vyleesi) is an FDA-approved prescription autoinjector. This page is educational. It does not provide dosing, reconstitution, administration, or any human-use instructions. The 10 mg mass is a vendor listing, not a published laboratory protocol and not the approved-product fill.

Simple Research Peptides (SRP) materials are for laboratory research only and are not for human or veterinary use, consumption, administration, diagnosis, treatment, or therapeutic application.

Laboratory identity is the first practical issue. Opened registries describe bremelanotide as CID 9941379 / CAS 189691-06-3 / UNII 6Y24O4F92S / Ac-Nle-c[Asp-His-D-Phe-Arg-Trp-Lys]-OH. SRP product pages do not print sequence, CAS, UNII, C-terminus, salt, or a public COA. A method written for Melanotan II (C-amide), afamelanotide, alpha-MSH, KPV, or Vyleesi is not automatically valid for this vial.

Confirm peptide identity, C-terminus (acid vs amide), stereochemistry (D-Phe), lactam closure, salt, and purity by LC-MS before treating a vial as the literature article or as NDA 210557 material. Independently sourced research peptides are not established as equivalent to Palatin clinical lots or to Cosette Vyleesi. Historical IN exposures and autoinjector-product conditions are study / label facts. They are not a reconstitution scheme.

No reconstitution scheme, no administration route, and no human or veterinary use protocol appears on this page. Research use only.

Sources actually opened for the locked draft. Do not add PMIDs or NCTs that are not on the allowed list.

Allowed PMID list used on this page: 2555512, 6777774, 12851303, 14963471, 15226502, 16412534, 17584130, 22335602, 27181790, 28189361, 31599840, 31599847, 35147466, 36189794, 36809187.

Allowed NCT list used on this page: NCT02333071, NCT02338960, NCT01382719, NCT00425256, NCT04179734, NCT03973047, NCT04943068, NCT05709444, NCT06565611, NCT06867835.

Product links are research materials, not treatment recommendations. Opened SRP PT-141 page: PT-141 10 mg Melanocortin Research Peptide Vial; category Research Compounds. Footer: for laboratory research only; not for human or animal use, consumption, administration, diagnosis, treatment, or therapeutic application. Sequence, CAS, UNII, C-terminus, salt, and a public COA were not printed. Do not confuse with Melanotan II 10 mg, KPV 10 mg, alpha-MSH (IUPHAR 1320), afamelanotide / Scenesse (1324), or the Vyleesi autoinjector (NDA 210557).