Melanotan I vs Melanotan II: Melanocortin Research Comparison
Understanding the structural and receptor binding differences between linear and cyclic melanocortin analogs in research applications.
Quick Comparison
| Category | Melanotan I | Melanotan II |
|---|---|---|
| Compound Type | Alpha-MSH analog | Alpha-MSH analog (circular) |
| Amino Acid Length | 13 amino acids | 7 amino acids (cyclic) |
| Structure | Linear peptide | Cyclic peptide |
| Receptor Target | MC1R (primary) | MC1R, MC3R, MC4R, MC5R |
| Research Focus | Melanocortin-1 pathway studies | Broad melanocortin system research |
| Purity Standard | ≥98% HPLC verified | ≥98% HPLC verified |
| Availability | 10mg vials | 10mg vials |
What Is Melanotan I?
Melanotan I (also known as Afamelanotide) is a synthetic linear peptide analog of alpha-melanocyte stimulating hormone (α-MSH). It consists of 13 amino acids and primarily targets the melanocortin-1 receptor (MC1R).
In laboratory research, Melanotan I is studied for:
- MC1R receptor characterization and binding studies
- Melanocortin pathway signaling research
- Selective receptor activation models
- Peptide stability and pharmacokinetic studies
Its relatively selective MC1R affinity makes MT-I valuable for focused receptor pathway research without significant cross-receptor activation.
What Is Melanotan II?
Melanotan II is a synthetic cyclic heptapeptide (7 amino acids) that acts as a non-selective melanocortin receptor agonist. Its cyclic structure provides binding affinity across multiple melanocortin receptor subtypes (MC1R, MC3R, MC4R, MC5R).
In research settings, Melanotan II is studied for:
- Broad melanocortin receptor system research
- Multi-receptor activation patterns
- Cyclic peptide structure-activity relationships
- MC4R pathway investigations
The non-selective receptor profile of MT-II makes it useful for studying the broader melanocortin system and receptor cross-talk.
Key Differences for Researchers
The structural differences between these compounds result in distinct research applications:
Structural Configuration
Melanotan I is a linear 13-amino acid peptide, while Melanotan II is a cyclic 7-amino acid peptide. The cyclic structure provides conformational constraints that influence receptor binding.
Receptor Selectivity
MT-I shows primary affinity for MC1R, enabling focused pathway studies. MT-II binds across MC1R, MC3R, MC4R, and MC5R subtypes, making it suitable for broader melanocortin system research.
Research Applications
Researchers studying isolated MC1R signaling may prefer MT-I for its selectivity. Those investigating melanocortin system interactions or MC4R pathways often utilize MT-II for its broader receptor engagement.
Stability Characteristics
The cyclic structure of MT-II generally provides enhanced stability compared to linear peptides. Both compounds require proper cold storage and protection from light for optimal stability.
Why Documentation & Testing Matter
In research settings, the reliability of results depends entirely on the quality and consistency of materials used. Third-party verification provides an objective baseline for researchers to trust their experimental inputs.
Third-Party Testing
Independent laboratory verification ensures unbiased purity and identity confirmation.
Batch Consistency
Each production batch is individually tested and documented for reproducibility.
≥98% Purity Standard
HPLC and mass spectrometry verification for research-grade quality assurance.
Transparent COAs
Complete Certificates of Analysis available for every product and batch.
Research-Grade Standards from Maple Research Labs
We're committed to providing researchers with consistently high-quality compounds, transparent documentation, and reliable service across Canada.
Canadian-Based Fulfillment
Fast domestic shipping from within Canada, reducing transit times and customs delays.
Independent Lab Testing
Every batch verified by third-party laboratories for purity and identity confirmation.
Research-Only Compliance
Clear labeling and documentation designed for legitimate research applications.
Consistent Quality Standards
Rigorous QC protocols ensure batch-to-batch consistency for reliable research outcomes.
Frequently Asked Questions
What is the main structural difference between MT-I and MT-II?
Melanotan I (Afamelanotide) is a linear 13-amino acid peptide, while Melanotan II is a shorter 7-amino acid cyclic peptide. The cyclic structure of MT-II provides different receptor binding characteristics and broader receptor affinity.
Why do researchers study melanocortin peptides?
Melanocortin peptides are studied for their roles in melanocortin receptor signaling pathways, which are involved in various physiological processes. Research focuses on receptor characterization, binding affinity, and pathway activation patterns.
Are these compounds approved for use?
Afamelanotide (MT-I analog) has received regulatory approval for specific medical conditions in some jurisdictions. MT-II remains a research compound. Products from Maple Research Labs are sold strictly for laboratory research purposes only.
What documentation is available?
All products have batch-specific Certificates of Analysis available with HPLC purity verification, mass spectrometry identity confirmation, and complete synthesis documentation.
How should melanocortin peptides be stored?
Lyophilized peptides should be stored at -20°C in a dry, dark environment. Reconstituted peptides require refrigeration at 2-8°C and should be used within recommended timeframes for optimal stability.
Explore Research-Grade Compounds
All products include third-party testing documentation, batch-specific Certificates of Analysis, and secure checkout. For research use only.
Research Use Only: Products are intended for laboratory and scientific research purposes only. Not for human or veterinary use. By purchasing, you confirm compliance with all applicable regulations.