What makes Melanotan-2 cyclic?

A lactam bridge links side chains within the sequence, closing part of the backbone into a ring and constraining the molecule's conformation.

Melanotan-1, at 1646.85 g/mol in Amino Fuel Labs records, compared with 1024.18 g/mol for Melanotan-2.

Are these approved for human use?

The research material supplied here is not approved and is not for human or veterinary use. Any approval in this molecular family applies to a specific finished pharmaceutical product, not to research material.

How are the two distinguished analytically?

By molecular mass, which differs by more than six hundred daltons, and by distinct chromatographic retention behavior.

Research Comparison Reference

Melanotan-1 vs Melanotan-2: Linear and Cyclic Analog Comparison

A structural reference distinguishing a linear α-MSH analog from a cyclic one, using verified catalog identifiers.

Attribute comparison

Verified attribute comparison for Melanotan-1 vs Melanotan-2: Linear and Cyclic Analog Comparison
Attribute	Melanotan-1	Melanotan-2
Compound class	Linear α-MSH analog	Cyclic α-MSH analog
Peptide or non-peptide	Peptide	Peptide
Amino-acid count	13	7 (cyclic core with terminal residues)
Receptor or pathway classification	Melanocortin receptors	Melanocortin receptors
Molecular weight	1646.85 g/mol	1024.18 g/mol
Physical form	Lyophilized powder	Lyophilized powder
Laboratory research context	Melanocortin receptor studies	Melanocortin receptor studies
Available from Amino Fuel Labs	Yes	Yes

Key structural differences

Melanotan-1 is a linear thirteen-residue analog of alpha-melanocyte stimulating hormone. Its chain retains the full length of the parent hormone with substitutions intended to increase stability.

Melanotan-2 is a truncated and cyclized analog. Cyclization through a lactam bridge constrains the molecule's conformation, and the shortened backbone gives it a molecular weight roughly six hundred daltons lower than melanotan-1.

That cyclic constraint is the defining structural difference and is also what makes the two behave differently in chromatographic separation.

Published research context

The melanocortin analog class has been investigated in receptor pharmacology research, and one linear analog in this family has been developed as an approved finished pharmaceutical product in certain jurisdictions for a specific rare-disease indication. That approval applies to a specific finished product and its manufacturer only.

Research material supplied by Amino Fuel Labs is not that product, is not approved, and is not for human or veterinary use.

Frequently asked questions

What makes Melanotan-2 cyclic?: A lactam bridge links side chains within the sequence, closing part of the backbone into a ring and constraining the molecule's conformation.
Which is larger?: Melanotan-1, at 1646.85 g/mol in Amino Fuel Labs records, compared with 1024.18 g/mol for Melanotan-2.
Are these approved for human use?: The research material supplied here is not approved and is not for human or veterinary use. Any approval in this molecular family applies to a specific finished pharmaceutical product, not to research material.
How are the two distinguished analytically?: By molecular mass, which differs by more than six hundred daltons, and by distinct chromatographic retention behavior.

References

PubChem — melanocortin analog records — National Center for Biotechnology Information
PubMed — melanocortin receptor analog literature — National Library of Medicine

Research use only. The information in this library is educational and is not medical advice. Products are not intended to diagnose, treat, cure, or prevent disease and are not for human or veterinary consumption.