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PT-141 Pro research peptide vial and box
PT-141 - Pro
  1. PT-141 Pro research peptide vial and box
  2. PT-141 - Pro

PT-141 – Pro

Pro Series
PT-141 (bremelanotide), a cyclic heptapeptide melanocortin receptor agonist
CAS 189691-06-3C₅₀H₆₈N₁₄O₁₀Approximately 1025.2 g/mol7 amino acidsCyclic peptideLyophilized powder

Price range: $50.00 through $450.00

Ships from lot NHS-PT1-20260817-09 · 10 mg vial · 99% purity · pH Solutions Lab See the COA
Why the Pro Series costs more
  • Synthesized in the USA. Domestic ground and air only, no ocean freight.
  • Released only above 99% HPLC purity.
  • Its own lot and its own published certificate.
How the Pro Series is made and tested
Ships from Austin, TexasUnited States only
Tested by an outside labNever in-house
Every lot publishedIncluding rejected lots
Same-day dispatchOn orders before 2pm ET
SKU: N/A Category: Tags: ,
BATCH
VERIFICATION
LOT NUMBER
NHS-PT1-20260817-09
10 mg vial
IDENTITY
Match (C50H68N14O10, 1025.2 g/mol)
CHROMATOGRAPHIC PURITY
99%
NET CONTENT
10.1121 mg (101.121% of 10 mg label claim)
Analytical characterization

Every result against its specification.

Lot NHS-PT1-20260817-09 · 10 mg vial · pH Solutions Lab · reported 29 September 2026 . The bar shows where the reported result falls against Astramide’s published release criterion. The notch marks the criterion.
Within criterion Above criterion Not on this COA
Test
Method
Criterion
Result
Result vs criterion
Status
Identity
Match to the labelled compound
Match (C50H68N14O10, 1025.2 g/mol)
WITHIN SPEC
Chromatographic purity
HPLC (294 nm)
at or above 99.0%
99%
95 at or above 99.0% 100
WITHIN SPEC
Net content
10.1121 mg (101.121% of 10 mg label claim)
80 120
REPORTED
Appearance
Visual
white lyophilized powder
White to off-white lyophilized powder cake, free of visible particulates
WITHIN SPEC
Water content
Karl Fischer
reported
1.352%
WITHIN SPEC
pH
reported
7.0
WITHIN SPEC
Water activity
within laboratory limit
0.2356 aw, pass
WITHIN SPEC
Microbial panel
not detected
Pass, 10 organisms and counts not detected in 1 g
WITHIN SPEC
Heavy metals
within laboratory limits
Pass. As, Cd, Pb, Hg each 0.000 ppm
WITHIN SPEC
Residual solvents
within laboratory limits
Pass, 12 solvents each 0.000 ppm
WITHIN SPEC
Sterility
sterile
Pass
WITHIN SPEC
Mycotoxins
within laboratory limits
Pass
WITHIN SPEC
Endotoxin
LAL
—
Not reported on this certificate
NOT REPORTED
Values are reported per vial unless otherwise noted. Every figure here is taken from the batch Certificate of Analysis and nothing else.
Certificate of Analysis
PT-141 - Pro · Lot NHS-PT1-20260817-09 · 10 mg vial · Lab No. NHS-PT1-20260817-09
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Quick reference

How to read this report

Same six keys on every Astramide product page. Only the values change.
1Lot numberMatch it to the number printed on your vial. If they differ, this report is not for your vial.
2IdentityMass spectrometry confirms the molecule is the one on the label. It conforms or it does not. There is no partial result.
3Chromatographic purityThe share of the material that is the target peptide. A purity figure quoted without a method is not a purity figure.
4Net contentHow much peptide is in the vial, as measured by the laboratory. A different question from purity.
5EndotoxinMeasured against a ceiling, not a floor. Sensitivity differs by laboratory, so results are not compared across labs.
6Laboratory, method, dateWho ran it, on what instrument, and when. A report with no named laboratory or no date is not a report.
Molecular profile

PT-141 - Pro, in structural terms.

PT-141 - Pro molecular structure
Sequence
Ac-Nle-cyclo[Asp-His-D-Phe-Arg-Trp-Lys]-OH (lactam bridge between the Asp and Lys side chains)
Molecular formula
C₅₀H₆₈N₁₄O₁₀
Molecular weight
Approximately 1025.2 g/mol
CAS number
189691-06-3
Peptide length
7 amino acids
Structure type
Cyclic peptide
Parent sequence
Alpha-melanocyte-stimulating hormone (alpha-MSH) core sequence His-Phe-Arg-Trp
Primary molecular target
Melanocortin receptors, chiefly MC4R and MC3R, which are class A G protein-coupled receptors that signal through Gs and cAMP. PT-141 is not selective and also acts at other melanocortin receptor subtypes.
Physical form
Lyophilized powder
PubChem CID
9941379

PT-141 (bremelanotide) is a synthetic cyclic heptapeptide. A lactam bridge between the side chains of aspartic acid and lysine closes a ring around His-D-Phe-Arg-Trp, the core sequence of alpha-MSH. The N-terminus carries acetyl-norleucine and the C-terminus is a free carboxylic acid. It differs from melanotan II only at the C-terminus, where melanotan II carries an amide.

Research profile

Where PT-141 - Pro appears in the literature.

Melanocortin Biology; Receptor Pharmacology; GPCR Signaling; Peptide Chemistry; Neuroscience
Research applications
  • Published studies have used PT-141 and related cyclic alpha-MSH analogues in:
  • Melanocortin receptor binding and subtype selectivity studies
  • MC4R and MC3R cAMP signaling studies
  • Structure-activity studies of cyclic alpha-MSH analogues
  • Conformational studies of lactam-bridged melanotropins
Experimental systems
  • Cell lines expressing cloned melanocortin receptors (MC1R, MC3R, MC4R, MC5R)
  • Membrane preparations for radioligand binding
  • Peptides in solution for NMR spectroscopy
Specific assays
  • Radioligand binding assays
  • cAMP accumulation assays
  • Receptor cloning and expression
  • NMR spectroscopy and molecular dynamics
Measured endpoints
  • Binding affinity at each melanocortin receptor subtype
  • cAMP production and functional potency
  • Receptor subtype selectivity
  • Solution conformation of the cyclic peptide
Pcs

Single Vial, Pack of 10
Strength

10mg
Mechanism and research context

What has been studied, and in what systems.

PT-141 belongs to the lactam-bridged cyclic analogues of alpha-MSH. Nuclear magnetic resonance and molecular dynamics studies of these superpotent cyclic melanotropins described how ring closure constrains the His-D-Phe-Arg-Trp core into a receptor-active conformation (Al-Obeidi et al., 1998).

Its main targets are melanocortin receptors. MC4R, the fourth melanocortin receptor to be cloned, was identified in 1993 as a brain-expressed receptor that raises cAMP when activated by melanocortin peptides (Gantz et al., 1993).

A review of melanocortin ligands developed between 1954 and 2016 traced how cyclic analogues such as melanotan II and bremelanotide were derived and compared their activity across receptor subtypes (Ericson et al., 2017). These studies place PT-141 in melanocortin receptor pharmacology research.

These are published research systems. They do not describe approved clinical applications, and they do not establish efficacy or safety in humans.

Cited literature

Gantz I et al., 1993. Molecular cloning, expression, and gene localization of a fourth melanocortin receptor. J Biol Chem. PMID 8392067. https://pubmed.ncbi.nlm.nih.gov/8392067/
Al-Obeidi F et al., 1998. NMR and quenched molecular dynamics studies of superpotent linear and cyclic alpha-melanotropins. J Pept Res. PMID 9650716. https://pubmed.ncbi.nlm.nih.gov/9650716/
Ericson MD et al., 2017. Bench-top to clinical therapies: A review of melanocortin ligands from 1954 to 2016. Biochim Biophys Acta Mol Basis Dis. PMID 28363699. https://pubmed.ncbi.nlm.nih.gov/28363699/

Evidence level
The melanocortin receptor pharmacology of cyclic alpha-MSH analogues, including PT-141, is well characterised in binding, signaling and structural studies. Statements on this page describe experimental systems, not outcomes in humans.
Handling and storage
As supplied
Lyophilized powder in a sealed vial. Held in laboratory-rated freezers from arrival to shipment.
Storage
Store per the conditions printed on the vial label. Avoid heat, moisture and repeated temperature cycling.
Handling
For qualified professionals in controlled laboratory environments, following validated laboratory procedures.
Frequently asked questions

About this compound and its batch data.

What is PT-141 peptide?

PT-141, also called bremelanotide, is a synthetic cyclic heptapeptide (Ac-Nle-cyclo[Asp-His-D-Phe-Arg-Trp-Lys]-OH) built around the core sequence of alpha-melanocyte-stimulating hormone. Its formula is C50H68N14O10, its molecular weight is about 1025.2 g/mol and its CAS number is 189691-06-3. PT-141 Pro is supplied as a lyophilized powder in a 10 mg vial. Sold for research use only.

What has PT-141 been examined for in published research?

PT-141 has been studied as a melanocortin receptor agonist. Its main target, MC4R, was cloned in 1993 and shown to raise cAMP when activated (Gantz et al., 1993, PMID 8392067), and reviews have compared cyclic alpha-MSH analogues such as PT-141 across receptor subtypes (Ericson et al., 2017, PMID 28363699). This page describes laboratory research. Astramide makes no claim about outcomes in humans.

What purity does the current PT-141 Pro lot reach?

Lot NHS-PT1-20260817-09 returned 99% chromatographic purity by HPLC at 294 nm, reported by pH Solutions Lab on 29 September 2026 under certificate 260824-899-NHS-1. Identity was confirmed as a match to bremelanotide (C50H68N14O10, 1025.2 g/mol). The lot meets the Pro Series release criterion of at or above 99% HPLC purity. The full certificate is published on this page.

How much PT-141 is in the vial?

The label claim is 10 mg per vial. For lot NHS-PT1-20260817-09, the laboratory measured 10.1121 mg of PT-141, which is 101.121% of the 10 mg label claim. Astramide publishes the measured figure exactly as the laboratory reports it, above or below the label. Net content and chromatographic purity are separate measurements.

How should PT-141 be stored for research use?

Lyophilized PT-141 is stored at -20°C and protected from light. Once reconstituted, the solution is held at 2 to 8°C and used within 14 to 30 days. Repeated temperature cycling and exposure to moisture should be avoided, because both can affect peptide stability and the comparability of experimental results.

Is PT-141 the same as melanotan II?

No, but they are closely related. Both share the same lactam-bridged cyclic core built on alpha-MSH. PT-141 ends in a free carboxylic acid (C50H68N14O10, CAS 189691-06-3), while melanotan II ends in an amide (C50H69N15O9, CAS 121062-08-6). They are separate compounds with separate CAS numbers, and receptor studies compare them directly (Ericson et al., 2017, PMID 28363699).

How is Astramide's PT-141 Pro tested?

Lot NHS-PT1-20260817-09 was tested by pH Solutions Lab, an independent ISO/IEC 17025:2017 accredited laboratory (A2LA R243, PJLA Testing #84351). The certificate reports identity, chromatographic purity at 294 nm, net content, water content, pH, water activity, a 10-organism microbial panel, heavy metals, residual solvents, sterility and mycotoxins. Results apply only to this lot.

What does Pro Series mean for PT-141 Pro?

PT-141 Pro is part of the Astramide Pro Series. It is American-made, synthesized in the USA, and moves by domestic ground and air only, with no ocean freight. It is released under its own lot, and only when HPLC purity measures at or above 99%. The full certificate for each lot is published on this page.

Research use only

This product is intended strictly for in-vitro laboratory research conducted by qualified professionals. It is not intended for human or animal consumption, clinical use, or therapeutic application. The statements on this page have not been reviewed by the FDA. These research peptides are not intended to diagnose, treat, cure, or prevent any disease. Research Use Only.

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