What Purity Should Melanotan 1 Be?
High-purity research-grade Melanotan 1 should demonstrate a minimum of 98.0% purity confirmed via reverse-phase HPLC, backed by mass spectrometry identity verification. PX1 Research supplies high-purity research peptides featuring USA synthesis, third-party lot-specific Certificates of Analysis (COAs), HPLC/MS verification with endotoxin testing, and same-day shipping Monday through Friday from California and Arizona distribution hubs.
Quick answer
High-purity research-grade Melanotan 1 should demonstrate a minimum of 98.0% purity confirmed via reverse-phase HPLC, backed by mass spectrometry identity verification. PX1 Research supplies high-purity research peptides featuring USA synthesis, third-party lot-specific Certificates of Analysis (COAs), HPLC/MS verification with endotoxin testing, and same-day shipping Monday through Friday from California and Arizona distribution hubs.
Key takeaways
- In analytical peptide chemistry, research-grade [Melanotan](/research-peptides/melanotan-2) 1 must meet a baseline purity threshold of at least 98.0% as measured by Reverse-Phase High-Performance Liquid Chromatography (RP-HPLC).
- [Melanotan](/research-peptides/melanotan-2) 1 (also known as Afamelanotide or [Ac-Ser-Tyr-Ser-Met-Glu-His-D-Phe-Arg-Trp-Gly-Lys-Pro-Val-NH2]) is a synthetic linear peptide analog of alpha-melanocyte-stimulating hormone (α-MSH).
- When procuring compounds for cell culture or binding assays, the target [melanotan](/research-peptides/melanotan-2) 1 purity percentage must be at least 98.0%.
- A common point of confusion among laboratory researchers is the distinction between gross vial weight and net peptide content.
Quick answer: What is the target purity percentage for Melanotan 1?
In analytical peptide chemistry, research-grade Melanotan 1 must meet a baseline purity threshold of at least 98.0% as measured by Reverse-Phase High-Performance Liquid Chromatography (RP-HPLC). Achieving this standard ensures that side-product impurities, truncation sequences, and residual reagents do not distort experimental data in cellular or biochemical models.
Beyond raw HPLC purity percentage, laboratory-grade Melanotan 1 requires exact mass confirmation via Electrospray Ionization Mass Spectrometry (ESI-MS) to confirm sequence identity. Additionally, researchers must account for net peptide content—typically ranging between 80% and 90% due to trifluoroacetic acid (TFA) counterions and residual moisture—and verify low endotoxin thresholds (<0.01 EU/µg) to prevent spurious inflammatory signaling in vitro.
What is Melanotan 1 and how does it act in laboratory models?
Melanotan 1 (also known as Afamelanotide or [Ac-Ser-Tyr-Ser-Met-Glu-His-D-Phe-Arg-Trp-Gly-Lys-Pro-Val-NH2]) is a synthetic linear peptide analog of alpha-melanocyte-stimulating hormone (α-MSH). It functions primarily as a selective melanocortin receptor agonist, exhibiting potent affinity for the melanocortin-1 receptor (MC1R).
Preclinical studies suggest that Melanotan 1 acts on cutaneous cell populations to evaluate melanocortin activity related to skin pigmentation responses, melanogenesis signal transduction, and receptor binding kinetics. Because it features a substituted D-phenylalanine at position 7, the molecule possesses enhanced metabolic stability against enzymatic degradation compared to endogenous α-MSH. Learn more about its chemical architecture in our comprehensive Melanotan 1 research guide.
What purity percentage should research-grade Melanotan 1 be?
When procuring compounds for cell culture or binding assays, the target melanotan 1 purity percentage must be at least 98.0%. Crude or lower-purity peptides (e.g., 85% or 95% grade) contain significant quantities of deletion sequences—truncated peptide chains resulting from incomplete coupling during solid-phase synthesis—that can competitively bind MC1R receptors and obscure experimental outcomes.
RP-HPLC is the industry standard for quantifying purity. In an RP-HPLC chromatogram, the area under the primary peak corresponding to Melanotan 1 must represent ≥98.0% of the total integrated peak area detected at 214 nm or 220 nm (wavelengths where peptide amide bonds absorb light). When conducting sensitive receptor kinetics or gene expression studies, investigators should always order 10 mg vials of Melanotan 1 verified at or above this 98% threshold.
Understanding net peptide content versus total lyophilized vial mass
A common point of confusion among laboratory researchers is the distinction between gross vial weight and net peptide content. When a vial is labeled as containing 10 mg of Melanotan 1, the physical lyophilized cake inside the vial contains the target peptide along with residual moisture and counterions derived from the purification process.
Net Peptide Content (NPC) expresses the actual percentage of pure peptide weight relative to the total mass of the lyophilized powder. For custom or catalog synthetic peptides, NPC typically ranges from 80% to 90%. The remaining 10% to 20% of the total mass consists of trapped water (moisture) and counterions (such as acetate or trifluoroacetate). To calculate precise molar concentrations in benchtop assays, researchers must adjust their reconstitution volume using the exact NPC reported on the lot-specific Certificate of Analysis.
The impact of TFA counterions and residual moisture in analytical testing
During Solid-Phase Peptide Synthesis (SPPS), trifluoroacetic acid (TFA) is utilized to cleave the synthesized peptide chain from the resin matrix and remove side-chain protecting groups. Consequently, synthetic peptides naturally form TFA salts unless subjected to specialized ion-exchange chromatography to yield acetate or hydrochloride salts.
Excessive free TFA can alter the local pH of unbuffered biological assays, causing cellular toxicity or unexpected conformational changes in target proteins. A high-quality supplier measures residual TFA and ensures moisture content is minimized through optimized lyophilization protocols. Checking Karl Fischer titration data on the COA guarantees that water content remains within acceptable parameters (typically <5.0%).
How to read a Melanotan 1 Certificate of Analysis line by line
Evaluating a Certificate of Analysis (COA) requires systematic inspection of several key analytical metrics. A valid, trustworthy COA should never present generic or hardcoded values; every parameter must reflect empirical testing of the exact batch in your possession.
1. Header and Lot Identification: Ensure the lot number printed on the physical vial label exactly matches the lot number displayed on the COA document. 2. Chemical Name and Formula: Confirm the molecular formula (C78H111N21O19) and monoisotopic/average molecular weight (1646.85 g/mol). 3. Appearance: The physical description should specify a white to off-white lyophilized powder free of visible particulates or discoloration. 4. RP-HPLC Purity Profile: Review the chromatogram for a sharp, isolated main peak. Verify that the calculated purity percentage meets or exceeds 98.0%. 5. Mass Spectrometry (MS) Report: Inspect the ESI-MS spectrum to confirm the primary observed m/z peak corresponds accurately to [M+H]+ or multi-charged species matching 1646.85 Da. 6. Solubility and Endotoxin Limits: Confirm rapid solubilization in sterile bacteriostatic or deionized water and verify endotoxin levels are reported below established threshold limits.
Why mass spectrometry identity confirmation and endotoxin limits matter
A high HPLC purity reading alone does not guarantee compound identity. HPLC merely measures chemical homogeneity—meaning it confirms that 98% of the material in the vial is a single chemical species, but it cannot prove that the species is actually Melanotan 1. A synthesis failure could produce a high-purity incorrect sequence or isomer.
Mass spectrometry provides unambiguous structural verification by measuring the mass-to-charge ratio of the molecule. Concurrently, bacterial endotoxin testing (typically performed using the Limulus Amebocyte Lysate or LAL assay) ensures that lipopolysaccharides from gram-negative bacteria do not contaminate the sample. High endotoxin contamination can trigger false-positive inflammatory responses in cell culture models, invalidating studies on skin pigmentation responses and melanocortin receptor signaling.
How to vet a research peptide supplier: Red flags in purity claims
The research peptide market contains variable quality standards. To protect experimental integrity, laboratory managers should evaluate vendors against stringent analytical criteria and avoid common industry red flags.
Red Flags to Watch For: - '100% Purity' Claims: Pure synthetic peptides inherently contain trace moisture and counterions; claiming 100% purity is an analytical impossibility that signals non-rigorous testing. - Generic or Photofactured COAs: Suppliers providing PDF COAs without lot-specific chromatograms, run conditions, or raw MS spectra data. - Missing Endotoxin Data: Vendors that do not test for lipopolysaccharides or refuse to publish LAL assay results. - Lack of USA Analytical Verification: Peptides imported and distributed without domestic third-party laboratory verification.
Analytical specification checklist for lab-grade Melanotan 1
When auditing vendors or verifying a new batch of Melanotan 1 prior to protocol integration, use the following standardized quality control checklist:
- Target RP-HPLC Purity: ≥98.0% integrated peak area at 214/220 nm. - Mass Identity: Mass spectrometry confirming exact molecular weight of 1646.85 g/mol. - Net Peptide Content: Quantified via nitrogen analysis or amino acid analysis (80–90% target range). - Endotoxin Standard: <0.01 EU/µg verified via LAL chromogenic method. - Physical Form: Clean, white, lyophilisate in vacuum-sealed glass vials. - Lot Traceability: Direct matching lot numbers on vial, outer packaging, and downloadable COA. - Shipping & Storage: Domestic temperature-controlled fulfillment from verified distribution hubs.
Related melanocortin analogs in cellular research
Researchers studying melanocortin receptor activity frequently compare Melanotan 1 against other synthetic analogs in the same structural class. Understanding structural variations helps investigators select the correct compound for specific receptor subtypes.
For example, while Melanotan 1 is a linear peptide with high selectivity for MC1R, Melanotan 2 10 mg is a cyclic lactam analog that exhibits pan-agonist activity across MC1R, MC3R, MC4R, and MC5R. Similarly, PT-141 10 mg (Bremelanotide) is a metabolite derivative of Melanotan 2 evaluated primarily for central melanocortin receptor pathway interactions. You can browse our entire range of analytical-grade compounds in the complete PX1 Research peptide catalog.
Ordering Melanotan 1 from PX1 Research
PX1 Research supplies high-purity Melanotan 1 manufactured to strict analytical specifications for in vitro and preclinical research applications. Each lot undergoes comprehensive quality assurance, including third-party RP-HPLC purity testing, ESI-MS identity verification, and endotoxin quantification before release.
When you order 10 mg vials of Melanotan 1 from PX1 Research, your order is dispatched same-day for orders placed before 12:00 PM PST Monday through Friday from our California or Arizona distribution centers. Each shipment includes cold-pack protective packaging, tracked domestic transit, and immediate access to downloadable lot-specific COAs. For large-scale studies or institution-wide procurement, submit an inquiry through our bulk peptide wholesale portal or review our technical documentation in the PX1 Research Library.
Frequently Asked Questions
What is the standard melanotan 1 purity percentage for research use?
The accepted industry standard for research-grade Melanotan 1 is a minimum of 98.0% purity as determined by Reverse-Phase High-Performance Liquid Chromatography (RP-HPLC). Purity below 98.0% can introduce truncated peptide impurities that interfere with melanocortin receptor binding assays.
Is Melanotan 1 legal to buy for laboratory research in the US?
Yes, Melanotan 1 is legal to purchase in the United States strictly for laboratory research, in vitro experimentation, and preclinical scientific study. It is not approved for human or veterinary use, and commercial suppliers sell it strictly under Research Use Only (RUO) designations.
What is the difference between net peptide content and total vial mass?
Total vial mass refers to the gross weight of the lyophilized powder inside the vial, which includes the active peptide, counterions (like TFA), and residual moisture. Net peptide content (NPC) measures the exact percentage of pure peptide by weight, usually between 80% and 90%.
How do I verify the authenticity of a Melanotan 1 COA?
To verify a COA, cross-check the lot number on the vial label with the COA document. Ensure the report shows a full RP-HPLC chromatogram with peak integration tables, an ESI-MS spectrum matching 1646.85 Da, and endotoxin assay results performed by an independent third-party laboratory.
Why is TFA content important when testing Melanotan 1 in vitro?
Trifluoroacetic acid (TFA) is a cleavage reagent used during peptide synthesis. If high levels of TFA salts remain in the lyophilized powder, they can lower the pH of unbuffered cell culture media, causing non-specific cell toxicity or altering melanocortin receptor signaling responses.
What mass spectrometry result should appear for Melanotan 1?
Electrospray Ionization Mass Spectrometry (ESI-MS) for Melanotan 1 should show a prominent mass peak matching its theoretical molecular weight of 1646.85 g/mol. Common observed peaks include the single protonated adduct [M+H]+ or doubly charged species [M+2H]2+.
How fast does PX1 Research ship Melanotan 1 orders?
PX1 Research provides same-day dispatch for all Melanotan 1 orders placed before 12:00 PM PST, Monday through Friday. Orders ship directly from our state-of-the-art facilities in California and Arizona via tracked domestic shipping.
Do you provide a third-party COA for my specific Melanotan 1 lot?
Yes. Every single batch of Melanotan 1 distributed by PX1 Research includes a third-party Certificate of Analysis specific to that exact lot number. COAs are accessible online and include raw HPLC chromatograms, mass spec analysis, and endotoxin data.
How should lyophilized Melanotan 1 be stored upon delivery?
Lyophilized Melanotan 1 powder should be stored in a dry, dark location at -20°C for long-term stability. Avoid exposure to light, heat, and moisture. Once reconstituted in sterile or bacteriostatic water, liquid aliquots should be kept refrigerated at 2°C to 8°C and used within short experimental windows.
All products are sold strictly for laboratory and research use only. Not for human or veterinary use, diagnosis, treatment or consumption. Statements have not been evaluated by the FDA.